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D-Bot Core-XY 3D Printer

by spauda01, published

D-Bot Core-XY 3D Printer by spauda01 Sep 6, 2015
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Summary

Remix of the Core-XY C-Bot.

300mm x 200mm x 325mm print volume

$550 approximate cost

Read the build guide before ordering parts.

Larger cover photo: http://i.imgur.com/oFbBbEb.jpg

Example prints made with the D-Bot: http://www.thingiverse.com/spauda01/makes

Demo Videos: https://www.youtube.com/playlist?list=PLtTX7qAE76Mwo2uvCK9YH6KMR-vQdPqly

All credit for the original C-Bot design goes to cfeniak.
Thanks to those who contributed at http://www.openbuilds.com/threads/c-bot.726/

Optional Components

Ramps 1.4 Enclosure - http://www.thingiverse.com/thing:1352320
Cable Chain - http://www.thingiverse.com/thing:1167746
Vslot Endcaps - http://www.thingiverse.com/thing:398515
Tubing Clips - http://www.thingiverse.com/thing:1232213
Bowden retraction stabilizer - http://www.thingiverse.com/thing:936611
Extruder Manual Feed Knob (small) - http://www.thingiverse.com/thing:474394
Vslot Channel Cover - http://www.thingiverse.com/thing:832077

D-Bot and C-Bot Differences

1) The lead screws and Z motors were moved forward to better lift the print bed from its center of gravity rather than use a fully cantilevered print bed.
2) Increased printable Z height to 330mm (~13")
3) Use of 20mm rails for the bottom sections to save cost and reduce bulk.
4) Various adjustments of printable parts, either to add plastic where it seemed like more rigidity was needed or to subtract plastic where it was not needed.
5) Accessories such as a simplified spool holder a cable chain for bed wiring
6) Relocated endstop mounting to maximize Y travel and utilize default homing scheme.
7) Overall reduction in cost compared to the original bill of materials (2$ square nuts vs 40$ Tnuts, etc.)

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Should I be concerned that the gantry is out of square with the frame? The frame is square, but when the left side of the gantry wheel plate is flush up against the left idler assembly, the right is off by about 1/2". I can drop that down to about 1/4" by pulling the frame out of square on the left side (The left side of the frame ends up at 14.125", where as the right is 14".)

Are your rails cut accurately? Did your printed parts come out clean? Loosen the bolts that hold the Hbar ends to the gantry rail and retighten evenly

I'm planning to do a larger build - 400x400 or 500x500 ... is there any reason I couldn't use the 76oz stepper motors in the BOM. Or should I get some 84oz motors.

If I get a different motor - do I need to configure them/tune them etc?

Printers with beds larger than 300x300 are very impractical, even with a volcano extruder large prints which take up most of the bed would take several days to print and if the power went out or you had a layer shift all that work would go to waste. If you printed small stuff you would be wasting huge amounts of power heating a giant bed you don't need. The larger and heavier the bed gets, the harder it is to keep it level and stable and with longer belts and a bigger XY gantry prints will have ringing artifacts. If you want to print giant objects just make them in pieces and assemble. Biggest size I would recommend anyone going on this style printer is 300x300x600 and that's only if you really know what you are doing and you build it well.

But back to you original question, I dont know.

Thank you for your experience and advice.

how many of those chain liks did u need ?

Is there any reason you have to use the ~1/4" spacers with the wheels? I'm currently on the Z axis, and I'm finding them difficult to thread onto the bolt. I can drill them out if needed, but I also noticed that once I adjust the wheels to be tight, they're no longer butted up against the spacers anyway.

That doesn't sound right. If you havent already, post your build by clicking 'I made one' and upload some pictures of the problem areas

I bought some aluminum spacers at the hardware store. I'll get photos up later this evening.

finally starting the build but am noticing the shims and spacers are pretty tight on the m5 screws, to the point where the spacers and wheels need to be threaded on. Should I open the diameter of the part and print again or is that ok?

I had to increase the ID by 0.4 mm and decrease the OD by 0.3 as well to have a better fit and better wheel roll. It also made installing the wheels less PITA.

Depends on the accuracy of your printer but I just drilled mine out to the right size.

Everything has fit perfectly and snug except for these... I could probably drill out the spacers but the shims would be really tough...

I used metal shims that come with the wheels. Was a kit of wheel, bearings, shims and locknut.

You are right, would be pita to drill those. If you want to reprint, scale in the x/y by say.. 5%? see how it goes.

I have been trying to build a D-Bot and have been having issues with the v-wheels wheels binding and not rolling along the v-slot. In an attempt to isolate the issue I placed a wheel, spacers and nut on an m5 bolt and tightened it up. When attempting to rotate the wheel i noticed that even though the spacers were transferring the clamping force to only the inner race of the bearing the wheel was no longer smoothly turning. I ordered metal spacers to put between the bearings instead of the printed spacers but am out of ideas.

Is this a common hurdle that everyone had to overcome?

Yes it was definitely a pain in the ass to get all four wheels to make full contact and not have it bind. I think I'm still having some minor problems. Right now its good enough until I decide to take everything apart and redo it.

2 days ago - Modified 2 days ago
beepbeep - in reply to bzillins

As everybody sets the distance between bed and nozzle differently, some people squishing the first layer down, others having it virtually floating, there's little chance that the printed spacers are going to work for everybody. Best thing to do is print them, caliper them, adjust and reprint until you get the size exact.

I'm thinking of swapping to the metal ones too. Are these the ones? Just the regular mini v wheel shims? http://ooznest.co.uk/V-Slot/Shims-Spacers/Mini-V-Precision-Shim

Those are the ones I bought, I'll let you know how they worked Saturday

If your shims are slightly too thin, they will allow the bearings to bind up. I had good luck with printed shims but others prefer metal shims

I cleaned up the spacers and probably undersized them accidentally, that makes perfect sense.

Thanks for the quick reply!

My wheels had to have 2 shims in the middle, not 1. After digging around, the website i purchased them from mentioned it too. Always wondered why they gave an extra shim when I bought them :)

Is anyone else having problems with the STL files?
And are these the latest ones?
Thanks

Anyone out there using a chimera or dual extruder set up on their D-Bot? If so are you using dual bowden extruders?

Also if anyone has their D-Bot enclosed would love to see that!

Can I use E3D All-metal v6 HotEnd Full Kit 3.00mm Bowden (24v) with this? All my current filament is PLA 3.00 mm
Also what about Bondtech QR Universal Extruder - 3.00mm?

I suppose if you had a 24v power supply, you might need to modify the extruder bracket. I've never tried 3mm filament so I'm not sure what other changes you would need.

Confused about changing filament using this bowden system.

I'm used to the direct drive extruder and I heat up my nozzle, push a bit of filament and then pull back - which pulls everything out of the hotend, then load and push the new filament through the nozzle until I can see it coming out. Then purge the old by extruding new.

Do you pull out the ptfe tube at the hotend side when changing filament? - Or - how is the best method for changing filaments?

Heat up the hot end.
Manually retract the filament by using the feed knob or command via repetier host or other program to retract 1000mm, which should be more than plenty to get out all the way out.
Insert the new filament, manually feed it forward or command the extruder to feed via software depending how long your bowden tube is.
Keep feeding filament 10mm at a time until it flushes out the old color and the filament is coming out at the new color solidly.

Does anyone know where to source a flat aluminum plate for a 300x300mm bed? I've looked at 12x12+ aluminum cast plate (Mic-6) but it only comes in 1/4" at the thinnest, which is pretty heavy stuff.

Why not a thinner aluminum plate as a heat spreader with glass on top to keep it flat

I'm worried the glass will warp over time when big prints press it onto the aluminum plate.

That won't happen unless you get really crappy glass or you are heating it to like 500C or something crazy

Hanging around /r/3dprinting I've heard of some cases of the glass warping along with the aluminum bed in normal conditions.

This comment has been deleted.

I use a 3/8" thick MIC6 plate (for some reason it was cheaper than the 1/4" plate) and it heats up quickly and does a pretty good job. It probably doean't come thinner than 1/4" because they can't guarantee flatness below that

5 days ago - Modified 5 days ago
geoxile - in reply to spiffcow

Can 2 typical nema17 motors really support that weight? That must be over 6lb, and another 3+lb from the aluminum extrusions.

Yep. I even use bed correction instead of springs so its constantly moving. It works fine.

Are you still running 1/16 stepper drivers? If not, think 1/32 would make difference?

Created a Facebook group to discuss this excellent printer

https://www.facebook.com/groups/1711323699127948/

Facebook is okay for kids posting photos of cats... I think Google groups is more suited to grown up things.

Would you mind if I created a Facebook group for this excellent printer?

Can you send me the path for that group when you have it set up? Or post it here

Go ahead

cool...can I use your pics? I'm in the process of making mine still

sure, just give credit and link back to http://www.thingiverse.com/thing:1001065

D-Bot Core-XY 3D Printer
Jun 24, 2016 - Modified Jun 24, 2016

I'm having aweird issue with slicing, specifically, so far, on the right motor mount. It's creating some mid-air triangles like there's hidden geometry in the STL file. It's highlighted yellow as a bridge in this shot:
https://i.gyazo.com/e501de6097190af75222a0af220d973f.png

Any insight?

Jun 25, 2016 - Modified 6 days ago
KDan - in reply to Kittera

Change layer height very slightly in Simplify 3D. For example, if you are printing a primary layer height of 0.2000mm, change it to 0.2001. That will fix the problem. This is a known bug in Simplify3D ver 3.0 that comes up occasionally. It may have been fixed in later versions.

However, some of the parts definitely have geometry problems. I'm attempting to edit the Right Rear idler and it is a mess. The Left Rear is OK. I'll be moving on to the motor mounts next. I'm working on modifying all the parts with extrusion channels to allow the use of hammer t-nuts without the risk of them bottoming out. I am really disliking the square head nuts. They bite into the extrusions and sometimes remain stuck when loosened. Makes it very difficult to make fine position adjustments.

Is this in Simplify3D?

I've just run the latest right motor mount through my copy of S3D (Version 3.1.0) without any issues. I used a 0.2mm layer height with 30% infill. If that helps.

Is there a wiring diagram and parts info for using a 120vac heated bed? Just not sure how to put that together.

If you are unsure, then don't do it, Stick with 12 or 24v systems. 120vac isnt something you want to play around with if you are unsure.

What he said

I get what you're both saying .. though I'd be unsure of doing any of this build without spauda01's excellent build guide.

so - if I stay away from the 120vac - what is the wiring diagram for using a 24v heat pad?

Jun 20, 2016 - Modified Jun 20, 2016
uglybob - in reply to goldentuna1200

Same as the build guide except with a DC-DC SSR and a 24V power supply, which is what I have done. And obviously the ground live etc will go to the 24v power supply and not to 120vac. Little common sense is required.

Is there a particular SSR that's recommended for a 12V 270W heater? I can't seem to find any DC-DC SSRs that would safely sustain 23A (I'm skeptical of these chinese ones on amazon and ebay).

I've heard these Fotek SSRs are junk and can be dangerous.

If you allow them to get too hot and overheat. You can get heatsinks and fans for them too.

At that current level, you might just go with a mechanical relay and control it in bang mode. Use thick enough wires and make sure all connections are strong, that's a lot of current. Maybe consider a 24v or 120vac bed

I am getting a 110VAC heater in, just some cheap silicone one from China, not sure about the quality. Besides the added danger of mains VAC the printer would need an extra big enclosure to fit my PSU (an ATX PSU) and also fit a second plug separately for the 110VAC heater. It would be a big thing to print before I can put the printer together. I guess if I can't find a SSR for this 12V I'm going to use the 110VAC heater. I don't think I could stand the clicking of a mechanical relay for hours on end.

So those relays are dangerous, but your chinese low quality mains heater is okay?

Sounds like you'll be burning the house down.

The 12V silicone heater beds all come from China too. And for the same power they use significantly higher current.

Im tossing up wether its worth going for a 300mm x 300mm heated bed of the 300mm x 200mm. Does anyone know if the dimensions listed in the build guide will allow for the larger bed to fit with ample space for the x carriage to move about?

I was also wondering if its worth printing in PETG over ABS or PLA, I noticed that allot of people in the comments section have used PETG on their build. Its just that I have some spare roles of ABS that I should probably use.

I've used ABS and printed on a Wanhao i3 which is supposedly incapable of it, so if you can print ABS then I would recommend doing so.

However, note the shrinkage of ABS will cause some parts to fit very tightly. I had to reprint all of the motor mounts scaled up by 2% in order that I could fit the motors without the mounts snapping or bowing... So scale up!

If you are capable of printing ABS with good quality then go for it, it's just easier for others to use PLA or PETG.
The frame sizing diagram leaves enough room for the nozzle to reach every corner of the bed and the alternate frame diagram is just 100mm deeper.

Jun 19, 2016 - Modified Jun 19, 2016
Calum736 - in reply to spauda01

Thank-you spauda01, I didn't even realize your awesome build guide had the dimensions for a 300mm bed. I have gone ahead and ordered all the extrusions I need. Can't wait to start building!

Hi, just wanted to say I'm doing some research for my own CoreXY design and this is incredibly well designed! Nicely thought out, nicely implemented, very clean and concise, so very well done! I'd use it myself except one or two things don't meet my criteria. Very impressed though :)

Just curious, what are the couple of things?

Sorry, that's what I'm adding in my design!

  1. Direct dual drive instead of Bowden, just personal preference.
  2. Experimenting with using belt-wire couplings to reduce stretch.
  3. Experimenting with a 25:1 gearbox to give 8 micron resolution without micro stepping (personal preference, micro stepping seems illogical to me)
  4. Using the 4 V-slot pillars as linear guides instead of adding rods. As there are 4 should give much better stability too.
  5. Guess this isn't really an upgrade but I'm adding my full graphic screen. Small things and all that rot.
  6. Unfortunately going to wire crossover due to symmetry and stability along XY carriage rails. Made this lovely little crossover system that uses two small canted bearings to pass the wires smoothly over each other. Also added in the tensioning mechanism to the back idlers. It's a shame, I really loved the dual line style.

I just finished printing the main frame parts. I'm heading back to my hometown tomorrow for a few weeks (away from printer :( ) but that's where I plan to set up my printer, so will see how it all goes.
Thoughts?
Also putting out a very brief video skimming on the topic tomorrow, can see it here: https://youtu.be/doZjsvfNmXA
Don't expect the link to activate till 11AM UST.

In the build guide it goes through the process of running PID autotune for the bed. I understand PID should not be used if you are driving the bed through a relay (as the relay really doesn't want to try and deal with PWM modulation).

Does anyone have thoughts on this?

You're thinking of a mechanical relay, not a solid state relay.

Ah cool thanks.

I did a diff between your Marlin zip and the same version directly from Marlin, 99% of the changes happened at configuration.h, is that correct?

Also, I see there is a new version of Marlin (1.1 RC6) that does include support for CoreXY, have you tried that one? Any improvements for us? :-)

Cheers!

Hi There,

I have been running on 1.1 RC6 for three weeks now and all seems to be working fine. I just compared the configuration.h and made changes and adjustments where needed. The only other change I made was in pins.h for the button direction on my LCD controller.

Only change I noticed was that the homing issue was resolved and I can home any axis while any of others are homed.

Anybody looked at the E3d heated bed and would you need a separate power source for it? I like the option to only heat zones based on the print seems much more efficient but not sure if the ramps can handle that sort of control.

I looked at it briefly before, I don't think it heats in sections it just uses traces of varying impedance to give a more even all over temp

What are your thoughts on this bed? http://www.ebay.com/itm/Improved-200x300mm-Dual-purpose-12V-or-24V-Heatbed-PCB-3D-Printing-reprap-USA/331881520007

I like it because it has zip tie strain relief built into the board.

Very true spauda01. The tracks are of differing size to allow a more even temperature even at the edge of the heated bed.

To quote e3D:

"We tested quite a few bed designs and types, but they all had the same critical problem: the temperature at the edges was significantly cooler than the measured temperature in the centre. This means that despite having your bed set and reading 110C to print ABS comfortably in the middle of the bed, the temperature towards the edges could be as low as 95C and this means parts printed at the full extents of the bed are going to suffer from warp and detaching from the bed.

Our solution was to provide more power at the outer regions of the bed in order to compensate for the lower temperatures being measured there. By using slight variations in the width of the PCB heater traces we are able to selectively provide more power to regions that would otherwise be running cooler. This results in a much more even temperature distribution over the surface of the bed."

oh i thought for some reason it was like the new gmax bed that heated in sections. But also seemed like a decent price if it is a quality part like most of E3s stuff is. I know they want an arm and a leg for the gmax bed.

I had been going to use the heated bed spcified in the BOM but I changed my mind when I heard about the e3D bed. The quality of the PCB heater is equal to or better than MIL spec PCBs, and I've worked with many of those.

so are you converting everything to 24v because that seems to be the biggest drawback to me. What if any are the ways around this. Can you isolate the bed. and still control it via the ramps. Seems way complicated....

No I'm not converting to 24V. I'm using a separate 24V PSU just for the bed. I'm using 12V for everything else including switching the SSR to control the 24V to the bed.

i don't see any amp ratings on the e3d bed. Does anyone know the specs

Filastruder tested it with the following result:

"Electrical data: 24v nominal (22.9v actual), tested at 10.01 amps at 25C (Fluke 179)."

Each of the Molex connector pins are rated at 5A and the bed uses four of them for the power connection.

Is the dc-dc relay in the BOM enough for this application you think. Looks like it is 40amp and up to 23v in and 60v out

Cool that works i already have a 15a power supply in the shop. Hope that will be enough.

Do yourself a favor and buy the SSR below instead of a cheap one. The cheap ones typically have an on resistance of 0.1 Ohms which doesn't seem like much but will rob 10% of your power input as heat. In a 24V 15A test I setup with one it was 79 to 80C at the huge heat sink. The one in the link has an on resistance of 0.006 Ohms and barely even gets warm at those current levels.

http://www.auberins.com/index.php?main_page=product_info&cPath=2_30&products_id=288

This may be a dumb question, but what units should we use with the stl files for the printed parts? It doesn't say anywhere in the build guide, and I tried mm, but it looks way too small.

Thanks, the parts I printed were just smaller than I expected. I really like your design, but I have one more question. Did you have an issues with the straightness tolerances of the vslot? Looking at the rails I received, they don't look very straight when I lay them on a straight surface.

I put them down on a wood table. Turned out the table was really warped, not the extrusion.

That's not good. Try other surfaces and complain if they don't look good

Dear designer thanks for share your design. Can I use rumba board to your design if its possible can you explain me how to configure codes? Thanks

Not the designer but have experience with Marlin.
If he's provided code, use it as it EXCEPT at the top of configuration.h where it says "define motherboard" replace the board he's using with the relevant name from the boards.h for the Rumba. Give that a whirl.
Basically all it needs is to know what connectors to send the signals to, so telling it what board you're using will let it do the rest. I hope this helps :)

hola, si quisiera poner una cama de 300 x 300 mm, que tengo que modificar?

Ver el final del documento Guía de creación de los cortes de carril que necesita para 300x300 .

What cable is acceptable to connect the heater cartridge to the RAMPS? The silicon wire that comes with the hotend isnt long enough to make it all the way.

Overkill?
http://www.jaycar.com.au/Wire%2C-Cable-%26-Accessories/Hookup-%26-Power-Cable/General-Purpose-Hookup/Red-15-Amp-DC-Power-Cable/p/WH3073

Jun 15, 2016 - Modified Jun 15, 2016
beepbeep - in reply to uglybob

I think hot end heaters are generally around 40W, so 40W / 12V = 3.33 Amps

I've used 18 gauge (only because I bought 200m a few years ago so still trying to use it up) though 20 would also be fine (and still suitably over-spec'd).

Handy table: http://www.powerstream.com/Wire_Size.htm

The link in the BOM for a few Hardware items are broken. Can anyone tell me if these alternatives will work?

M3 Socket Bolt, 20mm: http://www.mrmetric.com/M10842
M3 Socket Bolt, 25mm: http://www.mrmetric.com/M11563
M5 Socket Bolt, 40mm: http://www.mrmetric.com/M11220

The M5 is also very expensive, about 3x the cost in the BOM. Where can we get them cheaper?

just send them an email or call they will get you setup. the guys at mrmetric are very helpful

If you call them they can get the ones in the BOM.

Thanks! Some of the items they were getting in stock soon so he made a note in my order to send them out when they arrive.

How can I modify the firmware to not use endstops? thanks.

I remixed another spool holder to suit the D-bot here http://www.thingiverse.com/thing:1625705

Spool Holder for 20mm V-Slot/D-Bot/C-Bot - 30 x 100

Do you think the square nuts make any difference from the misumi T-nuts? I guess t-nuts are supposed to be a better fit for the slots of 2020 extrusions but does that matter?

Do you guys think something like this would work at all?
http://www.thingiverse.com/thing:1061769

M4 T Slot nut

I have tried the three (3) of them. The square-nuts from Mr. Metric are too small contact surface, as said before. The T drop-ins and the T Sliding nuts have an issue when connecting plastic parts that have the V-Slot elevated profile. Remember that both the nuts and plastic parts have elevated profiles to compensate the extrusion slot empty space. When both profiles are in touch there won't be enough movement to tight the plastic part, extrusion and nut ending with loose joints.

I ended sanding each T Sliding nuts to remove the elevated profile achieving a better surface contact. If I knew that before I would have bought something like this ones:

https://8020.net/shop/3206.html

Yeah i think I'm stuck sanding the nuts to... though wouldn't sanding the plastic be easier...

Have you tried putting the T-nuts in flipped? I guess the hammer nuts can't be helped.

The T-nuts (sliding or drop-in) are unable to be flipped upside-down like the square nuts do to their shape. The are made to have the best contact surface used as designed.

Jun 14, 2016 - Modified Jun 14, 2016
geoxile - in reply to rodelvalle

I see, so the printed parts designs have to be changed to get rid of the extrusion for the v-slots?

Are those really a dollar a piece?! Mr. Moneybags over here

Square nuts make a very secure frame, I'm not sure if T-nuts are worth the cost.

Having said that though, I'm doing a second build of the D-bot and have ordered these to try out (were recommended by someone in the comments here - much further down):

http://www.banggood.com/100pcs-M5-Hammer-Nut-Nickel-Plated-Carbon-Steel-Nut-Aluminum-Connector-T-Fastener-Sliding-Nut-p-1048442.html

My D-Bot is made using entirely those. They're great - and you can add / remove stuff after it's been built :)

I got these, apparently they need to be sanded down as where the eyelet is, it is extruded and bumps into the plastic on the printed parts made to fit the extrusions.

I wondered that from looking at the photo. The nuts I originally got (square nuts 10mm x 10mm x 3mm with no chamfer - totally flat) do a good job but they won't quite fit in as standard, I've been using a bench grinder to chamfer 2 of the lower edges then they fit quite snugly - flat against the extrusion when tightened and can't be popped in or out from the face of the extrusion.

I do about 50 nuts at a time at the grinder to break up the monotony of it... No big deal, but I would love to find something that is both low cost and 'just works'.

Yeah that was by me. I bought them after my concerns with the square nuts from Mr Metric.

I've got a mixture of t-nuts (http://www.makerstore.com.au/product/tee-nuts-25-pack/), square nuts and the drop ins from BG.

IMO: The T-nuts are the best if you can afford it, the drop-ins work better than the square nuts.

(Apologies for not giving you credit by name bob - laziness prevented me scrolling to find it :)

I also saw these on banggood... They look like they'll fit though I'm not 100% sure.

http://www.banggood.com/50pcs-M5-T-Sliding-Nut-Zin-Plated-Carbon-Steel-T-Sliding-Nut-for-2020-Aluminum-Profile-p-1048439.html

Jun 18, 2016 - Modified 4 days ago
KDan - in reply to beepbeep

They will fit, but they will bottom out on the raised channels on the printed parts just like the hammer nuts. The ideal solution would seem (at first glance) to be to use pre-assembly t-nuts like the ones from openbuilds or like these -

http://www.aliexpress.com/item/Zinc-Plated-Tee-nuts-for-building-machine-M5-bore-50pcs-per-bag-Free-Shipping/32345778338.html?s

Unfortunately, those have the threads recessed a bit and M5x10 screws can barely reach the threads when a washer is installed. (I have some and tried) M5x12 screws might work great thou if the screw doesn't bottom out in the channel. (UPDATE: It does...)

Ultimately, all of the parts with the raised channels could to be remodeled to allow a hammer T-nuts (or the ones you mentioned) to be used. The raised channel serves a purpose, so it should not be entirely removed - just in the area near the bolt holes. I've modified a few of the original C-Bot files myself, but I haven't seen any easily editable files (such as STEP files) for the D-Bot files anywhere.

UPDATE: I decided to tackle this. I've modified all of the parts that have raised extrusion channels. Hammer T-nuts can now be used without risk of them bottoming out on the raised portion of the printed parts. Modifying STL files was tedious. STP files would have been much easier...
I am planning multiple builds of a modified C-Bot/D-Bot type machine .The Hammer T-nuts are much more versatile, will cut assembly time and aren't that much more expensive than the square nuts (6.5 cents each vs. 4 cents each).

3 days ago - Modified 3 days ago
PJ79_Alpha - in reply to KDan

Hi KDan, is there chance that you could upload those modified files if possible?

Edit: Sorry, just noticed you only updated yesterday. No rush :)

Those look a lot better than the first BG link. I too want to know if these will work with the build. I'd be willing to try them out.

I ordered 1 pack to try them out so I can let you know once they arrive.

I didn't order the square nuts yet and just decided to order these instead. Square nuts would be $8 with probably some shipping and tax on top, 4x 50 packs came out to just under $20 with free 6-9 day shipping and no tax. Hope they work!

Square nuts are cheaper and capable of doing the job. t-nuts are better, more surface area on the extrusion, less chance to damage the profile.

Another question. Would there be any upgrades to add dual extrusion?

Look in the remixes

spauda01 - one more HUGE THANKS! for such a fantastic job of putting this together and such an outstanding BOM and Guide. Man - this is great!

LIke most - I'm looking to push this to a larer size - and have used the calculator, etc to figure what I needed.

Couple of questions though:
1 - on the calculator it refers to the Z-Platform: Gantry, and the CoreXY: Gantry, I wasn't sure - but it looks like those corespond to R & Q respectfully on your frame reference diagram. Could you confirm if that is correct?

2 - It seems that most printers out there stay in a similar 'smaller' size. Is that because of the limited size of heat beds or limits on stability and accuracy of going larger?
I guess the question really is ... is there a point where this design won't handle the stabily/speed/accuracy for a given size. e.g. 500x500 bed and 500 lead screw. - what would be largest size (within reason) that this design might handle?

I don't need a heated bed - as I've been using a Lexan (polycarbonate) build plate and don't need heat/hairspray/glue) - so I'm really not limited on what size bed I could make. (link to my build plate thread ref: http://goo.gl/A22fP1)

In the BOM it says that the printer has trouble maintaining 100c for ABS. I would like to have the option to print ABS in the future. Are there any alternative heat pads that someone could recommend?

well, for ABS you will likely need an enclosure to begin with. as for the bed, you can go 24V!

Yeah I was planning to build an enclosure once it's running. Have tons of spare acrylic! So just grab a 24V bed heater? I don't know a huge amount about the electronics side of things yet. I DID buy the 12v PSU listed on the BOM already. I'm guessing it won't be able to send the full 24V to the heat pad in this case? If so, I'm wondering what components need to be upgraded to make it work great with ABS?

Running the bed at 24v seems to be outside your skills. Just look at the printer that this page is remixed from, the Cbot. He used a different 8x12 bed and he prints abs

Jun 10, 2016 - Modified Jun 10, 2016
Marksman79 - in reply to spauda01

Thanks for the reply! I did look at the c bot, and noticed that he uses the same 12v power supply that this build uses. A different, more expensive bed but one that can handle 24v just like the one in the D bot. And the wiring diagram is also the same. So what are the changes I would need to make in order to use the D bot bed at 24v? Is it just getting a 24v PSU and soldering the wires to the 24v points on the bed? It seems that the relay is good up to 32v.

And how much of an issue is the heated bed running at 12v as far as ABS printing goes?

There are plenty of beds out there that can reach 100C with 12v, the bed pcb I am using just happens to have a slightly higher resistance than others so it doesn't consume as much power and doesnt get as hot. Running your bed at 24v is more advanced than you think and it involves more than just getting a different power supply and connecting it.

Get a 24V silicone heater mat (Aliexpress has loads, many of which can be made to your specification) and a 24V power supply. You can step down from your 24V power supply to run your electronics at 12V if you don't want two separate power supplies.

I bought my bed from avanti circuits, they have an ebay store and sell a 12x12 heated bed for $48 free shipping, and it can draw up to 20A if I remember correctly, so should heat up quite fast. I plan to mod a 600W PC PSU to supply enough energy to this.

are these the folks you are talking about. http://www.ebay.com/itm/12-X-12-Heatbed-Kit-w-Relay-Prewire-and-Thermistor-for-3D-Printing-/262314890386?hash=item3d132f9492:g:kWgAAOSwDuJW1dWd

They recommend an extra powersupply that seems a little overkill if you are not running it at 24v. In the middle of my build but looking at his and the makerfarm 12x12 bed.

That's the one I got, but I bought the relay separately (the one from the BOM), so instead of $69 paid $48. I will just use a 600W PC PSU, and should have plenty of power for this without needing a separate PSU.

I'm considering trying to minimise the Z-axis motor "drift". Would it be worth me taking my 5 steppers and in some way testing them out to try and find 2 which are very closely matched to use for the Z-motors?

Quick question..... how did you bond your cork sheet to the underside of your heated bed ?

Jbweld epoxy

thanks mate :)

Another question. Would there be any benefit in the following modification:

1 - Cut an extra Q piece, and add it to the other side of O and P.
2 - Add extra 8 wheels to that side, plus the printed parts
3 - Move K very close to the center of H and J

Would this add more stability (as now the bed is supported from the 4 corners), or unnecessary bulk? By my calculations, I will have some leftover extrusion, so could potentially use it for this...

Comments are appreciated :-)

Unnecessary

Can these V-slot extrusions be replaced by something else? Like normal extrusion or something?
I can't find these where I live and it would cost 96$ to ship if I were to buy them from OpenBuilds, that's too much for shipping!

What country are you in?

The problem is the wheels... V-slot has the profile to mate with the wheels, other standard extrusions do not.

You may have a vendor in your country selling V-slot (we do in the UK), so it's not limited to buying from openbuilds.

Theres a remix that replaces most of the rails with standard Tslot extrusions but some rails would still have to be Vslot, thats just how it is designed.

I bought 1000 square M5 nuts and they don't fit the V-slot. The link from the BOM is dead. Does anyone know the dimensions that the nuts have to fall within to fit?

link in the spreadsheet works fine for me.

Jun 8, 2016 - Modified Jun 8, 2016
beepbeep - in reply to beepbeep

My nuts are 10mm square x 3mm thick. I presume the ones from Mr Metric were 8mm square. If I chamfer two of the edges I can get them to fit... Got a lot of time at the bench grinder coming up :)

Jun 6, 2016 - Modified Jun 7, 2016

Hello, I'm planning to build this dbot. I want to calculate extrusion lengths for 400*400mm bed and planning on using a 500mm lead screw to gain as much z height possible. Will it be okay to use the cbot rework calculator from original cbot page? With offset lead screw option and adding 30mm to the bed width as the calculator suggests? Any suggestions would be really appreciated. Thank You

Hello! What LED controller did you use?

There's a link in the "additional comments" column of the "12v 5050 LED Strip" row. The controller case is easy to pop open to extract the board, and it slides right in to the optional ramps 1.4 enclosure listed under Thing Details.

I wondered this too and couldn't find it in the BOM. I think any cheapo (chinese variety) LED controller works, but I really didn't want any colour changing effects or remote control so just bought white LEDs (not RGB... this isn't a christmas tree) and will wire to 12v.

Everything is in the bill of materials

Jun 4, 2016 - Modified Jun 4, 2016

I am running into another issue.
Once I got everything up and running and calibrated, I started my first print. The first 3 or 4 layers went on fine and then the nozzle stopped heating and I got a cold extrusion prevented error followed by a heating error.
Now the strange thing is that this only happens during a print. I can manually extrude a whole spool with no temp drop-off so i know it is not a hardware issue. I even swapped out to a different E3D (Genuine) that I had on my other printer and same results.
I am not very savvy programmer, could this be a firmware issue or a setting I am missing?
Seems to me like once it drops from 205C on the first layer to 200C on the next that it doesn't stop on the way down?
UPDATE: It happens when the part fan turns on, so when the infill layers start. It just starts dropping and never stops.

Make sure your part fan nozzle isnt unintentionally blowing on the heatblock and cooling it down

I disabled my cooling and its looking great now (at least for a 1st print).
It drags on the bed if its pointing any further down. I can always re-design a new shroud that is less intrusive to my setup. I print mostly PLA anyways so cooling is not as critical for me.

Post some pictures to your Dbot make page of the nozzle and fan duct, if you followed what i did it shouldnt be that different, mine works pretty well and doesnt blow too much on the hot end and it still has clearance from the work

Done.
I have to remake the part anyway in PETG. Its PLA and melted a bit for being so close to the block.
The only thing I can see different from yours is the positioning of my heater block wires. Can't see that really being an issue for cooling conduction.

You have the long end of your heatblock pointed at the duct, look again how my hot end looks

The end of the fan duct had slightly melted because it was PLA. I re-printed in PETG and now it is working fine with cooling fan enabled. The melted end of the duct allowed for increased air volume to be blown onto the heater block, causing the block to reduce in temperature.
Lesson to all: Fan duct in ABS or PETG for optimal results.

You still need to look at how your heatblock is oriented. I've been using a PLA fan duct for months just fine. The fan duct was designed with the assumption that the long end of the heat block would either face sideways or towards the front.

Alright I will try it out. Always up for experimenting.

Jun 4, 2016 - Modified Jun 4, 2016

Is there enough clearance in the Y axis to rework the print carriage to put a laser module or second extruder with the 300mm wide bed?

Also on the Z access, since I haven't built this yet I am not sure how much play there is on the bed, but would it make sense to extend the shaft column up to fit a spring and a nut to ensure there is always pressure down don the primary lead screw nut to avoid any movement in the z axis? I'm sure the steppers could handle the extra friction from the second nut given the gravity assist pulling the bed downward.

Was there any particular reason you chose the stacked belt layout for corexy? Does it give any problems on the carriage because the belts are on different levels?

The moment (torque) forces from the 20mm offset are small and easily handled by the mini wheels of the XY carriage. The belts are offset in this design to allow the belts to run parallel and not need to cross in the back like other coreXY designs. At the time of the original Cbot design this was novel, now lots of design CoreXY designs use this approach.
A distance of 20mm was chosen so that the belts could run through portions of the extrusion to provide a cleaner and simpler design. You could reduce this to the belt width plus a clearance (say 6mm +2mm), if you redesigned and didn't want to run the belts through the extrusion.

About the corexy design, do you know what would happen if x and y axis motion systems had different resistance? Like if I used two different types of linear guides for the axes.

Each belt will have a component of X and Y so I think it will be fine. The belts should still be tensioned similarly though and both guides should have a relatively low resistance to travel as that is desirable for any linear guide. You should take a look at the differences between an H bot versus a CoreXY setup.

Jun 3, 2016 - Modified Jun 3, 2016
geoxile - in reply to cfeniak

That's very helpful, thanks. I've been looking into adapting the D-bot design to use smooth rods or linear guides. Do you think the torque from the 20mm can be handled by a pair of x-axis smooth rods arranged next to each other (as opposed to on top of each other)? I assume linear guides can.

~16 inches is quite a long span for smooth rods, thats one of the advantages of the vslot is that it doesnt sag over spans

Wouldn't a pair of 10mm rods be fine? It'll only be supporting a carriage for a bowden hotend and the x-axis will lose a bit of span if I were to use smooth rods.

Jun 3, 2016 - Modified Jun 3, 2016
spauda01 - in reply to geoxile

Ultimately you're talking to the wrong crowd :-p, I adopted the Cbot design specifically because I don't like smooth rods. I think that was cfeniak's thinking too.

Check out the fusebox for a smoothrod based corexy.

I actually did consider the fusebox but I didn't like the frame. I've seen the spinoffs with 20x20 extrusions but in general the one leadscrew approach and the offset base (the feet) look strange to me.

You're free to remix this design however you want, It's totally open source

Thanks senpai.

You could, but why would you want to? Do you mean just for the XY bar so that you can use a specific type of extruder carriage? That would makes sense as there are carriages made to specifically fit that arrangement. Not a great design though for spanning distances, vertically spaced is better IMO.
There are lots of CoreXY designs out there that use smooth rods already so it would makes sense to design off of those as the integration of V-slot as the linear motion guide and frame is one of the design highlights of this printer (or fatal flaw if you don't like the concept).

On the rods I've talked to some other people designing printers who claimed that wheels had some play that good smooth rods didn't. But ideally I'd like to use linear guides over either. And D-bot (and C-bot) seems to have good documentation and an active community, and the design is good. It just needs a few changes to fit a different motion system, at the expense of some lose of volume.

KDan - in reply to geoxile

I have used Delta printers with both MGN-12H linear rail, and Delrin rollers riding on aluminum extrusion. In my experience the rollers running on extrusion as just as rigid as the linear rail bolted to an extrusion. If someone claims that they have play or slop in their roller wheel setup, then they don't have them properly pre-loaded. On a Delta printer, I prefer the the linear rail because they are maintenance free. That is what my Kossel has.
On this CoreXY machine, the V-slot wheel setup has much lower moving mass. The linear rails are HEAVY. You don't want to be throwing the weight of the linear rail around if you are after high speeds and high accelerations.
Smooth rod is a double looser... they are not rigid enough across large spans, and it you use larger diameter rods to try to compensate, you really have a boat anchor on your hands.
The only drawback to the Delrin wheels that I've seen it that they, and the extrusions - need to be kept very clean in order to run super smoothly.
For what I believe the design objectives of this machine are, I don't see it benefiting from smooth rods or linear guides. It would only make it less rigid and/or more sluggish. As a Delta printer fan, I'm actually interested in making this machine even lighter on its feet, not heavier and slower.

Jun 6, 2016 - Modified Jun 6, 2016
geoxile - in reply to KDan

The plan for this printer is to print <10mm parts as accurately as possible and also mount a dual extruder with direct drives (Flexion dual extruder for mk 10). I have a hard time believing that the V-slots an rollers could be as well fitted as linear guides. As for rigidity, the Y-axis 9mm or 12mm guides will be mounted on the top of aluminum extrusions while the X-axis will be a 12mm or 15mm guide mounted at each end to the Y-axis guide blocks. I don't think the Y-axis will have any trouble since it's fully supported by the extrusion it's mounted on, and Misumi's aluminum extrusions show that the 20x40mm extrusions have greater mass/m than the Hiwin MGN12 guide (rail + block). I could even mount a MGN12 guide rail onto a 1515 extrusion and it'd only be 12.5% more massive per meter than a 2040 extrusion. Adding wheels might make things more even.

KDan - in reply to geoxile

2040 extrusion is overkill, that's why I redesigned with 2020 (Half the weight). Printer is not operational yet, but with the rollers properly preloaded, it is very rigid. A Kossel I've used which has the rollers instead of the MGN12's that my Kossel has feels just as rigid. I wouldn't have believed it at first either. But seeing is believing. The V-slot, V-wheel setup is very good.

I have to agree with spauda01 - you'd be much better off with a much smaller machine.
As far as SLA machines go, you can build a LIttleRP for much less than the price of this printer (not counting the DLP projector of course). No one printer can do it all. Personally, I still prefer my Kossel for small medium sized FDM prints. You do have to spend a little more time getting on intimate terms with the beast however.

geoxile - in reply to KDan

I'm a little skeptical but I might try V-slots on a different project. For now I almost have the design for linear guides nearly done, though it'll have to wait a few days while I'm away.

I still need a FDM printer for those larger utility objects, but I'll consider the littleRP for a future project. According to the creator there's a LittleRP2 coming up and it'll be the same price as the current littleRP, so it's probably worth waiting a while for that. I'm mostly concerned that the print volume might be so small that I'll rarely use it, in which case just ordering prints from 3Dhubs or shapeways might be more economical. But we'll see.

Why are you going to use such a huge printer to make tiny objects? Look into a Form2 or something SLA based

I want it to be scalable of course. That's just an example of what I want to achieve in terms of accuracy and precision. And a Form 2 would be 3.5x the cost, which just isn't in the budget.

It was part of the Cbot design. It works fine, the print carriage only moves in x and y, its not able to twist at all

This is pretty simple, but putting the M3 nuts in their pockets in the rear idler assembly and getting then to line up with the idler bearing screws can be a PITA, The pockets for the nuts are MUCH deeper than they need to be and the nut will fall far below the proper position to line up with the screw.

Take your calipers, set for 8.5mm, insert the M3 nut in the pocket and then insert the back end of your calipers in the pocket. Turn the part so the nut falls and sits on the end of the depth measurement bar on your calipers. The 25mm long M3 screw for the idler bearings should line up with the nut and the screw will go right in.

You really don't even need that nut, the bolt threads into plenty of plastic. It's just a leftover from the old design

I printed the parts on my Delta printer which print holes very close to their specified dimension. Correct me if I'm wrong, but I think they are 3mm holes. I found that I could turn the 25mm M3 screws into the holes almost by hand. If I tried to tighten them with a hex key wrench, they slipped with very little force. That was the only reason I put the nut in.
They might have stayed in place without the nut, but in my case I felt better putting them in.
For someone whose printed parts had slightly undersized holes, I believe you are correct, they nuts would be totally unnecessary.

Is the M3x10 for the extruder tensioner flange a mistake? The picture shows the tensioner is counter sunk, which would work, but the stl file isn't. Did you mod the part or the length of the bolt?

Fixed

Thanks!

I guess everyone just uses a longer screw with some washers.. I have to reprint my extruder anyway, as I had the parts printed on 3dhubs and the hub decided that 30% was more than enough infill (I am new to this, so didn't know until it was too late). I hope the parts last long enough to print new ones. I have an ABS glue made up and am fixing splits and cracks as they appear as best I can. I have a roll of PETG waiting for my SSR to arrive.

Also, as a general note for others, I tried the white PU GT2 belts, and they are not suitable, they are too stiff and don't take the corners without rubbing on the parts. Stick with the black ones.

Well that's weird. I've never noticed that before and I'm not sure what happened to the file. It's supposed to be an M3x10 countersunk as shown in the photos. I'll fix it tonight and reupload. I'm surprised nobody noticed and I'm not sure how people have been working around it

Finally up and running!!...sorta
I have uploaded all the firmware and only the extruder motor is able to turn.
All motors make a noise when I try to manually move them in Repetier, but they only move the axis maybe 1mm.
Is this an issue with the stepper drivers? The steppers should be plenty strong to work in this application.
I have them adjusted to 0.5v, could this be the issue?
Just wondering if any of you out there are running into similar problems.

Did you put jumpers under each driver board

This was the solution. I had totally forgotten to put them in during my initial setup.
I found this out late last night.
At least it was something so simple!

Unless you bought the same stepper motors and are using the same drivers as the creator, you will need to calculate the Vref for your particular components and set accordingly.

What drivers / motors have you got?

I've got everything printed (in ABS) but just can't get a perfect print of the H-bar ends, they always seem to develop a split at the very top of the flat base just before it meets all the ribbing. I guess there are some weird forces going on here - the split doesn't develop until the part is cooling after printing.

I've even tried rafts, and though I did get a good print I couldn't get the rafts off cleanly enough that I'd be happy using the part.

I was wondering if I should reduce the number of shells and use a 50% infill or something for these parts - appreciate we're after strong, solid parts here, but I've gone through half a reel just on these 2 parts and somewhat lost where to go from here.

ABS is often a problem with larger parts with sharp corners. Sometimes printing hotter to get better layer bonding helps. ABS has its place, but some of the parts in the D-Bot are just not ABS friendly. I only use ABS in parts where pliability or heat resistance might be an issue. I would not discount PLA. I've had good success when using PLA on other printers I've built. Not all PLA's are created equal. Some are more brittle than others. Printing temperatures can have a significant effect on the strength of PLA parts also.
I'd agree that PETG is probably better. It has better layer bonding than ABS and has greater tensile strength. It is also less brittle than PLA. However, for really large parts, I've had warpage problems with PET and found PLA was the only type filament that would get the job done.

I'm all printed now... I don't use PLA at all so am using what I've got. I consider PLA fine for those printing out toys (99% of domestic 3d printing it seems) but hopeless for structural parts due to the insane level of brittleness - tightening down a screw into a PLA part goes through me!

I purchased my first spool of PETG to print the parts for the D-Bot to avoid the shrinkage problems presented by ABS. Printing a couple of smaller parts first allowed me to tune the printer settings for the PETG and got quality prints quickly. Had no problems with shrinkage and got good bed adhesion with glue stick on glass. All structural parts were printed at 100% infill none required rafts, although I did use a brim on several of the smaller parts. I printed all parts on a well used and modified DaVinci 1.0.

Don't give up - I found the D-Bot build to but a great project and I couldn't be happier with its performance.

I hadn't considered PETG on my Wanhao i3 - I thought I was pretty much restricted to ABS or PLA, though I print with ABS mainly flawlessly so I think I might give PETG a try soon.

I've managed to print one of the H-bar ends successfully now (inspired by uglybob's comments below I made a flimsy shroud for the whole printer out of thin art-card which seemed to keep the heat a bit more uniform - and being there to take the part off the bed shortly after printing instead of it finishing in the middle of the night helped avoid splitting on cooling I think), so I should be okay.

Now to order the remainder of the parts and get busy.

The splitting can be from too much infill (~>80/90%), bad layer adhesion, or uneven cooling of the part.

I dont use ABS because of these "quirks" but keeping the whole printer and the part in warmed chamber while its printing and letting the whole lot cool evenly when its done helps reduce those stress splits. Splits from part of the print cooling and shrinking quicker than the rest. Some people even just put a cardboard box over the whole thing.. not sure this works for you and YMMV.

Thanks Bob. The printer (only a Wanhao i3) doesn't have a cover, but it is in a pretty-well sealed room where there are some computers rendering so the ambient temps are around 30 degrees celcius at all times with no draughts.

I'll try completely covering it with a box though... Will try anything.

Thanks again.

I print almost exclusively in abs. Layer adhesion can be a problem at low temperatures. I usually print at 255-260.

I've been printing at 250 with good results generally, just had problems on the H-bar ends and the rear idler parts with them coming apart on cooling, but might try going higher in future. It seems to help to get the parts off the bed as quickly as possible - the bed retains heat and keeps the bottom warm while the upper parts are cooling/shrinking, and it's this I believe that caused the parts to develop splits.

With the relay, does the bed heat up faster? How long usually takes to go to 60-70C?

The relay is only dependent on what heat bed you use. If its rating or supply(AC/DC) is more than what your controller can supply, then you will need the relay(DC/AC,DC/DC).

Awesome job on this project, the build document is so well done a complete novice should be able to follow it. I've started printing out parts for my own build. Looks like it would scale well... any thoughts on whether or not it would scale to 24x12x12 or larger? The extruder carriage would be heavier, and the heated table would be heavier, so would the motors be able to handle the extra weight without stalling?

Do you mean 12x12x24 (LxWxH)? This guy did something similar http://www.akeric.com/blog/?page_id=3063

No, I'm thinking larger X-Y axis. I have a Solidoodle 4 and the least accurate axis seems to be the Z... I've never printed anything with more than 4 or 5 inch height, but I need more X and Y. Right now I have to print some things in pieces and sand them to fit and glue together, so I'd like to be able to make some larger items. I was looking at heated build plates and saw one that was 500x500mm for $180, and thought that might be a good size. I imagine it would be easy enough to adapt your build to accommodate this plate, but wonder if the added weight might cause stalling on the Z axis, or even the extruder carriage because the V-channel is longer/heavier.
I'll probably start off building a 12x12x12 with your build docs, and if everything goes well (meaning I don't screw it up royally) would like to try something bigger. Your design would be very easy to modify for a bigger X and Y, but I think the Z might need 4 lead screws, powered by 2 motors and all connected with a belt

Expanding up is easy, expanding X and Y seems like a huge pain and probably not worth it. Look at the link I posted to see what kind of quality he gets on the 24inch tall build

Jun 1, 2016 - Modified Jun 1, 2016

Ok, assuming I go for a 300x300 bed, and also want to go for a 500mm leadscrew instead of 400mm, would these cuts make sense for the 20x40 extrusions?

1.5m: 620 488
1.5m: 620 413 448
1.5m: 620 433 433
1.5m: 620 413 463

Any other things I should take into consideration (besides the also longer GT2 belts)? Will 100mm extra on the Z mess things up?

Cheers!

Jun 1, 2016 - Modified Jun 1, 2016
Carrot_or_Stick - in reply to Piglet

Hey Piglet,

Thanks for replying to my comment below. Good catch on making 4 x 1.5M lengths work! Didn't catch that the first time through. From what i can tell the extra 100mm is the only change that we would need to make for the 500mm lead screws for the frame. The belts we need are 2 x 2.2M (from another reply in these comments). Worst case scenario is that the design wouldn't work with the taller frame but at that point we could just cut off the extra length from the rails and rods we have and go with the original design.

The only calculations I've done are for the original build and the 300x300 version. Any further modifications are up to each builder to decide

Mr Metric doesn't carry M3X25mm socket bolts? Is there an alternative?

I would contact mrmetric i sent them the list of bolts i needed and they had everything but one and suggested an alternative to what i needed. Even loaded it in my cart for me.

They also might just be out at this time. You could try reaching out to them (I heard they are helpful) to find out when they will be restocked.

bolt depot maybe

yup, thanks! Excited to build this bot.

You happen to have a link to the bolts you found as a replacement on bold depot? Their site is not very user friendly.

Are there any considerations for the Z-axis bed when building a 300x300mm version? I'm worried about tipping of the bed on the far end without any support.

You need to move the lead screws forward and find the center of mass of the new larger bed so the bed is lifted from the center

Also noted to find the center of mass, take the whole bed assembly off and balance it on a piece of dowel or a sharpish edge so you can find the balance point from the front and back.

Hope that marks sense......

same as trying to balance a pencil horizontally across a finger?

How precise is the fit of the wheels on the aluminum extrusions? Is it comparable to linear bearings on good smooth rods?

Hello is there a reason you Chose PLA or can i just use ABS?

Its just what I had, if you can print ABS that would give more durable parts

It's a beautiful thing. Thanks for the detailed build guide - I hope to make this.

I am currently printing parts out for this build because I absolutely love how clean and organized you've made it.
Do you happen to know where i could find a setup to make it direct drive? I cross messaged over on The Director's Triple C/C-Bot page as well hoping he would be able to point me in the right direction. I still plan on using the E3D v6, but can't quite tell if that's the same hotend he's using.

Thanks!

Look at the printer this one is remixed from, he has a direct drive option

Will that extruder module work with the D Bot?

Congrats on your printer, looks really nice.

I got a question. Went thru the build instructions and i didn't see how you are adjusting the wheels fit the extrusions.Openbuilds does it using eccentric spacers but i don't see them during assembly. Wondering if you don't tight that way, how much play you get between wheel and extrusion.

Thanks

The D-bot has oblong holes for the X/Y axes to allow for you to adjust the wheels, and the holes are actually slanted to tighten the wheels against the frame as they're tightened. I'm finishing my build up this weekend, and it's pretty easy to adjust those.

Thanks. That sounds great. One more question on the parts. Do you happen to know what infill and layer height is recommended to print? Thinking 70% @ 0.2mm w/ 0.4mm nozzle. Maybe will go with 0.6 nozzle but 70% @ 0.3mm. Thinking PETG. Any advise and tips are welcome

Definitely no less than 70%, higher if you can. PETG or ABS would be more durable than PLA

I went 90% PETG.... absolutely awesome stuff.. no cracks, no stress marks.. works really well and strong.

first person to print something 12"x8" contact me... Not sure where i will be buried yet...

Cmon, this printer is awesome.. but the build volume is ludicrous....

Yeah it needs to be a bit bigger for sure.

You can make the 300x300 version. This printer will actually be a big upgrade in size for me as I am building the 300x300 version. I currently only have a 200x200x110 printer and it hurts me to turn down orders that I can't fit on my bed...

May 26, 2016 - Modified May 26, 2016

I have a set of 500mm lead screws (accidentally said threaded rod) that I plan to use in a future build along with a 12"x12" heated bed. Theoretically I should only need to use the cut guide in the appendix and add 100mm to the lengths of rails A, B, C, and D to use them right? I would probably need an extra rail to accomplish this and re-order some of the cuts.

Love the work you have put into this and all the help you continue to give folks building your bot. Presentation is spot-on too!

Jun 1, 2016 - Modified Jun 1, 2016
Piglet - in reply to Carrot_or_Stick

I don't think you need an extra rail, just a bigger one, see my comment above (waiting for OP's reply), theoretically you can accomplish a 300x300 bed + 500mm leadscrew with the following 20x40 extrusion cuts:

1.5m: 620 488
1.5m: 620 413 448
1.5m: 620 433 433
1.5m: 620 413 463

Still waiting for further replies before I take the plunge! :)

I wouldnt recommend using threaded rod, lead screws only

May 27, 2016 - Modified May 27, 2016
Carrot_or_Stick - in reply to spauda01

Bump (see edited comment above)

Sorry i meant lead screws. I have 2 500mm lead screws with the same specs in your design

Awesome build! I greatly appreciate all of the work spauda01 put into everything. I was wondering what the effects would be if I used these

(http://www.amazon.com/Nema17-Stepper-Motor-4-lead-Connector/dp/B00QEXSCE8/ref=sr_1_1?ie=UTF8&qid=1464273319&sr=8-1&keywords=nema+17)

steppers instead of the ones listed in the BOM. I already have them so I could save $50 if they'll work. I am not super savvy when it comes to the electrical side of things so I don't know if I would fry anything if I plugged these in without changing any settings.

Those are functionally identical to the ones listed in the BOM, however you get 80% of the rated torque. What this means is you will not be able to run the printer at extremely high accelerations without losing steps, and the extruder will be less powerful.

I prefer to use a geared stepper anyway, and for normal print accelerations (for detail), they should still be fine. The high torque is just to have more headroom and more flexibility when trying to take the printer to its limits.

May 30, 2016 - Modified May 30, 2016
KDan - in reply to Masterjuggler

Actually, those motors are quite superior to the ones called out in the BOM. I would say almost ideal. The only thing I would personally prefer is even less rotor inertia on the X-Y motors.

Holding torque is irrelevant - you don't print standing still. Torque at high stepping rates is what matters if you want to achieve high speeds and high accelerations. Those motors have an inductance of 2.6mH, the ones in the BOM are almost double at 4.8mH.

Lower inductance means those motors will have a much flatter torque curve. The ones in the BOM will start off with slightly more torque at 0 RPM, but once the motor starts to spin, the torque will start dropping much faster than the 2.6mH motors from Amazon. You can also buy those motors direct from omc-stepperonline for $9.16 qty 5. There will be shipping charges however, so you'll have to compare final prices. Either way, they will ship from China.

For maximum performance at high speeds, I wouldn't use anything less than a 24v power supply. The rule of thumb is up to 20x to 25x the rated voltage of the motor. Voltage ratings are mostly irrelevant anyway - current limits are what matter, The voltage applied to the motor varies enormously as motor speed - and reactance - changes. The goal is to achieve constant current. That is a primary purpose of the stepper drive.

KDan - in reply to Piglet

Not enough information on either one of those motors. No inductance values are given. The first one is described as 12v - that is often an indication that it is a higher inductance motor. I would not consider either one of those.

For low inertia motors to drive the X-Y axes, I'm using 17HD34008-22B motors. For the extruder and the Z-axis (single motor) I'm using heavier 17HD48002H-22B motors. Both are low inductance versions with values around 3mH. All will be run on external 24 volt stepper drive modules.

Jun 7, 2016 - Modified Jun 7, 2016
Piglet - in reply to KDan

Here is the info on each motor from the datasheets. If you can tell which one works better for extruder and x/y and z axis, that would be appreciated! :-)

http://www.aliexpress.com/item/Free-shipping-any-Country-4-lead-Nema17-Stepper-Motor-42-motor-NEMA-17-motor-42BYGH-1/32673417497.html

Series Model 17HS4401
Rated Current(A) 1.7
Phase Resistance(Ω) 1.5
Phase Inductance(mH) 2.8
Holding Torque(N.cm) 40
Motor Length(mm) 40
Step Angle(。) 1.8

http://www.aliexpress.com/item/NEMA17-Stepper-Motor-34mm-12V-1-5A-0-4N-m-for-3D-Printer-Free-Shipping/32666641594.html

Series Model 17HS8401
Step Angle : 1.8 °
Motor Length : 48 mm
Rated Current : 1.8 A
Phase Resistance : 1.8O hm
Phase Inductance : 3.2 mH
Holding Torque : 52 N.cm
Detent Torque : 2.6 N.cm
Rotor Inertia : 68 g.cm2
Lead Wire(No) : 4
Motor Weight(g) : 400g

http://www.aliexpress.com/item/NEMA17-Stepper-Motor-40mm-Long-1-2A-Free-Shipping/32341280650.html

Series Model sl42sth48-1504a
Step Angle : 1.8 °
Motor Length : 48 mm
Rated Current : 1.5 A
Phase Resistance : 1.6 ohm
Phase Inductance : 2.8 mH
Holding Torque : 5.5 kg.cm
Rotor Inertia : 68 g.cm2
Lead Wire(No) : 4
Motor Weight(g) : 360g

Cheers!

I'm leaning towards 2 x sl42sth48-1504a for the Z, and 3 x 17HS4401 for x y and extruder.

KDan - in reply to Piglet

First consideration - Low inductance
Second consideration - low rotor inertia
Third consideration - higher holding torque

I would prioritize your selection in that order.

Your selections look good to me!

Remember that a 24 volt power supply will give far better performance.
Also, DRV8825's don't work well with low inductance motors on higher voltage. They don't have enough dynamic range on the PWM output. If you want to use an inexpensive driver module, A4988's will work better in this situation even though they have lower current rating and coarser microstep options.

May 23, 2016 - Modified May 23, 2016

Spauda01, thanks so much for all your work on this! I've got mine built - I'm having trouble with a heavy 300x300 bed(lulzbot aluminum plate, heatbed, and borosilicate glass) and bed movemen/vibration while printing, so I'm going to try mounting the lead screws front and back and seeing if that helps. I've also printed out the rework c-bot STL's for the z slide backet that extend farther on the rail. If this doesn't work, I'll try and kludge together the triple c-bot from what I've got so far.

I'm looking to switch over to the e3d titan carriage that ElmoC designed - http://www.thingiverse.com/thing:1535933. The endstop mount is not included and I'm trying to figure out how to use with the carriage back. I tried in sketchup to modify the d-bot carriage back, but all I managed to do was mangle the model. :) Is anyone willing to take a stab at adding the endstop mount to ElmoC's design?

Edit - I messaged ElmoC and it sounds like he is going to try and edit/create a backplate.

C-Bot E3D Titan Extruder Carriage
by ElmoC
May 24, 2016 - Modified May 25, 2016
Chairman_Miow - in reply to nickmig

Hey, I did this recently. I'm at work right now but ill post some files later (I'm not sure about copyright issues with the files I modified). I added holes for the endstop and its protrusions and modified the parts to work with the diicooler ( https://www.thingiverse.com/thing:1025471 ) Finally I added the cable routing point at the top.

I cant guarantee that I have it perfect yet as its still the first iteration of my modifications and im still setting my printer up but so far it looks good

edit - hmmm according to the copyright on the Diicooler I cant share the modified fan shroud file. I can share the modified backplate and frontplate and it should be no trouble to add whatever fan adapter you like to it

DiiiCooler for Wanhao Duplicator i3

I WANT THIS PRINTER !!! THANKS FOR SO MUCH EFFORT TO MAKE IT AN EASY BUILD....ANYONE CONSIDERING A 1000MM LEAD SCREW FOR INCREASED BUILD H ??? OR WHAT WOULD ANYONE CALCULATE THE MAXIMUM BUILD H WITH THE CURRENT EXTRUSIONS??? THINKING OF USING 2040 FOR THE BOTTOM AS WELL TO CREATE ROOM FOR A BOTTOM PLATE AND SOME REMOVABLE DOWN WEIGHT??

Hello, first of all I am grateful for sharing. I have a question.
What are the dimensions of the sigma profide?
I must have missed it.
x, y, z sigma profile What measures?
thanks for the answer.

Hi bud,

I've sorted out the heatbed, it was a combination of the wire from the 5a to the 11a and the heatbed wires in D8 not being fixed properly (doh).

Is it possible that you could tell me the implications of using a psu rated at 12v, 12.5a, 150W. Will it work with this set up? (I.e did you fit a psu that is over spec? Or is the psu you have used what I actually need?)

Cheers

That power supply is too small and it will probably break. I only recommend using the parts in the bill of materials

Hi, how did you route the front stepper motor wires. I have OCD and hate wires :)

drilled holes in the extrusion and feed the wires down the middle. requires some pre-planning or lots of assembly/dismantling/assembly to marked it out and drill, feed cables and put it together etc.

Thanks. I though so much.

If you do that file down the holes so they are very smooth and put a couple layers of heatshrink around the wires where they pass through the hole in the metal. You don't want any shorted wires and with lots of vibrations extra care is needed

Thanks for the advice. I`ll use rubber grommets.

Having an issue with my heat bed.
The heatbed is wired up as per reprap and yourself suggests, however I get no output on the heatbed.
Any ideas?
(Also the D-Bot is amazing, thank you for designing this!)

Does the relay light up? Did you put a jumper wire between the two positive power inputs on the ramps board

Jumper is now on, ramps board lights up but still no output from bed

Does the relay light up

No, there's no light on the relay

I think that may be the issue, I assumed that was just a power input for the led controller

Does Z stay in sync? I like everything about the design, but thinking about a bigger build area (300x300, and maybe taller), and also using a belt and only one Z stepper. That would save cost of one stepper and ensure Z never goes out of sync. Thoughts?

KDan - in reply to Piglet

I don't particularly like the two motor setup either. I've started modeling parts for a single motor system to drive the dual lead-screws. Something like this - only with a much shorter and less unwieldy belt run.

http://www.openbuilds.com/threads/c-bot.726/page-87#post-35616

In my design, there are two idlers built from the same flange bearings used elsewhere in the design. The idlers and motor are both mounted on the same central extrusion. It is arranged in a "T" configuration to maintain a 180 deg belt loop on all driving and driven pulleys. The center portion of the "T" is very short. This gives the shortest possible belt length requirement.

I've thought about doing that too.
The two Z stepper things is just a classic reprap setup. It stays pretty well synced but after several prints and moving up and down long distances a few missed steps can add up.

Ok, looks like I found a solution for this without the need to redesign anything. If you are using ramps with a single hotend, you can simply separate the z motors in individual drivers, and let them sync individually with separate endstops, that solves the problem as each time you home, you get z to sync. I could not find the feature on your existing posted firmware, but it is available on RC6, it's called Z_DUAL_ENDSTOPS under configurationadv.h.

I will test it out once I get everything assembled.

May 20, 2016 - Modified May 20, 2016
infmz - in reply to spauda01

Is it possible to plug another stepstick in extruder 2, and mirror controlling signal from Z axis stepper in marlin software? I think that would partially fix that problem.

There would still be slight differences in wiring and components etc. the only way to have them perfectly synced is mechanically connected

Yeah, I have an i3 and after 5 or so large prints I have to realign because of missed steps.

I saw another design that uses 3 lead screws and a belt on the bottom, but looks overly complicated, so I think I will stick with your design!

May 20, 2016 - Modified May 20, 2016
Masterjuggler - in reply to Piglet

I was actually thinking about trying out 90 degree gearboxes with linear rod, with each box mounted right where the two steppers are currently. I feel this would be easier than belts due to no need for a tension system.

I'm about 30 prints in on this printer and I am definitely noticing misalignment.. I've got my two z steppers wired in series.

https://www.thingiverse.com/thing:372530

Nema 17 right angle gearbox with spiral bevel gears
by dasaki

As a suggestion.....If you want to go down the mechanical path than use the setup from the triple C bot. Its what im going to do if the dual motor setup doesnt work out for my 300x300.

http://www.openbuilds.com/threads/triple-c-bot.1255/

The biggest issue with the triple C bot design here is the requirement for super expensive lead screws with the ends turned down. 60 bucks each is a little bit too much for that...

If there was a cheaper, belt-driven, single stepper design it would be perfect.

I'd design it myself but I dont have any ideas for how the lead screws can be held in place at the bottom without the expensive lead screws

Where are you paying $60 each for leadscrews? Ballscrews maybe, but not leadscrews. They are about $10-$12 each.

I've used these for an adjustable Z-bed in a laser cutter I designed and they work quite well. What I did in the laser cutter build was to turn them down to 5mm with a lathe on one end. I machined a small step on the end in order to incorporate a thrust bearing to properly handle the vertical loads. A conventional 5mm ID ball bearing was then fitted along with a conventional GT2 drive pulley.

I plan to replicate this general approach with my CoreXY build. I'm in the process of modelling new printed parts to accomplish this and I'm also waiting for some of the other mechanical parts. When tested and complete, I will publish it.

I decided to go the route suggested by uglybob, thanks for that. As for the 60 dollar turned leadscrews from the triple C bot BOM here: http://zentoolworks.com/product_info.php?cPath=16_15&products_id=125
Sorry they're $46.00 not $60.00, I must have been mistaken. I couldn't find turned down lead screws anywhere else.

If you don't have a lathe, then yes - it can get expensive to have someone turn them down for you.
I don't think I'd put an 8mm ID pulley on an 8mm leadscrew. Not precise enough. Also, it's just not the right way to do it... :-)

Get an 8mm ID pulley (or drill out a 5mm one) for one side and an 8mm lock collar for the top. There are cheaper options, not all ways have to be done the same to get the same result. :)

i.e.:
http://openbuildspartstore.com/lock-collar/
http://openbuildspartstore.com/gt3-timing-pulley-40-tooth-high-torque-series/

You would need to add a few cm of rail to the sides or lose some z travel. Unless you either have the electronics mounted over the belts or mount the belt system over the electronics (both reducing z travel), you would need to mount the electronics on the back or side, out of the way. Of course, I'll need to do some rearranging if I go with the gearboxes, but I'd still be able to have everything bottom mounted and nice.

My 14 year old son & I have been looking for a good DIY 3d printer to build (we've discovered the limitations of our cheap delta printer) and this one looks like a great project to embark on.
I've managed to locate local suppliers for almost all parts in the BOM (I live in Australia) but I'm struggling to find the specified stepper motors (KL17H248-15-4A, 76 oz-in).
I'm just wondering if there are any Aussie builders out there that know of any local sources for these motors? Alternatively, are there other motors that I could use (such as these)?
http://www.ebay.com.au/itm/5PCS-59Ncm-Nema-17-Stepper-Motor-2A-4-wire-1m-Cable-for-DIY-3D-Printer-CNC-Robot/171828613083?_trksid=p2141725.c100338.m3726&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20150313114020%26meid%3Dd76c8e9c714d41e08a995c687d2bede1%26pid%3D100338%26rk%3D19%26rkt%3D28%26sd%3D171993372625

Thanks in advance
Matt

Hey mtodman, i made a d bot in melbourne and I used those exact motors (from austeppers.online) in my build! so far theyre working well (build pictures still incoming)

Hey Chairman_Miow, what drivers are you using with those steppers? How hot do they get?

May 19, 2016 - Modified May 19, 2016
Chairman_Miow - in reply to Helix70

I'm using chinese knockoff drv8825 's I bought 5 from here:

(http://www.ebay.com.au/itm/351478190866?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT)

They get pretty warm when I print but dont burn my fingers, I adjusted the vref to 0.55v (from memory - could be wrong)

Oh, so you are limiting the current to 1.1A?

May 18, 2016 - Modified May 18, 2016
spauda01 - in reply to mtodman

That link looks good, any stepper which is nema17, 1.8degree, and at least 76oz-in should work.

May 17, 2016 - Modified May 17, 2016

Thanks for the outstanding build, guide, and comment support. I'm running into a bit of a problem and could use some insight:

When adjusting the H-bar ends, the wheels are very sensitive to the tight bolts. This isn't too much of an issue for the top rollers, but it does come into play on the bottom ones. If I tighten the lower bolts enough to remove all vertical play, the spacers bind up the wheels and prevent them from rolling freely. If I loosen to the point where the wheels roll freely, they aren't held against the rail snugly. Any pointers on this?

I'm to the point where I'm ready to break out the Dremel and grind down some of the spacers so that they don't touch the outer bearing race.

The spacers shouldnt touch the bearing outer race, are you using the spacers from the parts page?

Well, I figured it out. I ordered spacers and shims from OpenBuils, since I didn't feel like fussing with so many small parts on my current printer, and I think the C-Bot BOM used them instead of printed ones. Turns out those spacers require a shim between the spacer and bearing.

Lesson learned: If you're going to be lazy, do your research first.

Thanks for the quick reply!

Yep, I noticed so many people having that problem on Cbot builds with their stupid spacers and shims so I said screw it I'll just design and print shims the right size.

What lead screw would you recommend since the one in the BOM has been ended by the seller?

Hi, is there any reason I can't use 60mm steppers? I can't tell if the Z axis has the room or not.

I'm planning to go the other direction - especially for the X-Y motors. If you are after higher printing speed, you don't need holding torque, you need a motor with low inductance and low rotor inertia. A 34mm motor with an inductance value of around 2.5 mH would be able to run at high speeds and have the torque needed to do rapid acceleration/deceleration without skipping steps. Big motors may have large holding torque, but they are not agile. They also tend to have stronger resonances and more vibration in general.

Interesting. Thanks KDan, I did not know that. So would you still go for torque for the extruder?

To a certain extent, yes. But a fair amount of speed is needed with Bowden extruders also. This because of the large retract distances. You want to be able to retract and re-engage the filament as quickly as possible. Large retractions incur delays that can become very significant if your extruder cannot move rapidly. On parts that require a lot of retractions, the delays can really add up.

The idea of simply selecting larger steppers in order to gain torque at operational speeds is often wrong. Here is an article that explains some of the reasons. It's targeted at Delta printer builders, but the same principles apply to all 3D printers.
http://reprap.org/wiki/Choosing_stepper_for_a_delta

I've been through all of this with a Kossel I built. I initially used sub-optimal motors in the build. Upon identifying the proper motors and installing them, I was able to turn up the step rates MUCH higher with no skipping or missing steps.

I don't know, try it on the sketchup model

May 16, 2016 - Modified May 16, 2016

Great job on refining the C-Bot! The build guide is fantastic and will likely make this project more attractive to a lot of people.
Build in progress. Modifying the HBar ends and carriage to use a single 20mm V-slot extrusion instead of 20x40mm to reduce moving mass.

balu - in reply to KDan

By HBar you mean the X axis? The 20x40 is used for the belt run. That's more an aesthetic reason, but to me a free hanging belt doesn't look clean.

Also doesn't the higher profile give you more stability against the rotation of the carriage as a result of the belt pulling at two different points? Besides sag issues, but those can probably be ignored at these lengths.

KDan - in reply to balu

Not quite sure what you mean - the belt is free hanging regardless of which extrusion width is used. With the 20x40 you have a wider extrusion behind it, but with the 20x20 the belt still runs very close to the extrusion and isn't what I'd consider to be hanging out in the open.

As far as stability of the X-axis carriage is concerned, I think it's pretty much a non-issue on 3D printers where there are virtually no loads... Except on the Z-axis carriages, where I am absolutely retaining the 20x40 extrusions. (But, by placing the lead-screws centrally under the build platform, those Z-axis loads have been dramatically reduced)

If you want a specific example of an CoreXY printer that uses a single 20mm extrusion for the X-axis H-Bar, look at the Fusion3 printers.

I think sometimes we fail to keep in mind the whole motivation for adopting the CoreXY kinematics. The goal is to be able to print faster by being able to use higher accelerations. You have to reduce moving mass to accomplish that. What is the point in eliminating moving motor mass and then replacing it with a heavier than necessary moving structural mass?

All of the parts for the new H-Bar ends and Carriage have been modeled and test printed. I'm now just waiting on hardware to start putting it all together. I'm working on optimizing several other aspects of the machine to reduce mass and inertia as well. I want this machine to have the agility of my Delta printer, but without the calibration hassles.

Are you revising the belt position to be centered WRT the carriage to eliminate twisting?

Also, I'm interested in what you're planning.. I'm working on a similar effort, though my goals so far have focused on increased rigidity rather than reduced movement mass.

May 24, 2016 - Modified May 24, 2016
KDan - in reply to spiffcow

spiffcow - I'm not currently looking at revising the belt position. That would entail remodeling many of the C-bot/D-bot parts to keep the belts in the same parallel planes, and I'm more interested in getting the printer up and running first. I don't expect the current amount of belt offset to be a problem, but I could be wrong. That's why we have to test out new ideas, right?
I feel that the stiffness of the carriage could be increased if necessary with alternate materials and/or mechanical reinforcement.

I think the twist might be more noticable with a 2020 extrusion, but I'd love to hear how it goes!

I'm planning on keeping the 2040 and the same positioning, but using a tight tolerance low friction slider instead of v-wheels to prevent unwanted movement.

There is no twisting or unwanted movement in the print carriage on the Vrails

spauda01, How can you have no twisting force if the belts aren't in the same plane? Or are you saying it's accounted for in the design?

I can't speak to your carriage specifically.. My build is a C-Bot with a direct drive carriage and an uncommonly heavy motor, and I can see a very small bit of twist when changing directions at high speeds. Perhaps it's just due to the lack of precision in the belt tension (they feel the same.. but I don't have anything to actually measure the tension with). Maybe my v-wheels are too loose -- I haven't been able to completely remove play on the carriage without locking up the wheels.

I'm not trying to negatively criticize the design. It's the best printer I've owned by far. I'm not doing this because I'm dissatisfied with the design, I'm just using it as a learning experience.

May 24, 2016 - Modified May 24, 2016
KDan - in reply to spiffcow

I think your variation of the design could possibly be why you are seeing the slight twist. You say you are using an uncommonly heavy direct drive extruder motor - but the original design calls for a Bodwen with almost no mass on the carriage.
The main idea of CoreXY is to reduce moving mass, but it will inherently have very long belts with "unique" belt routing requirements. It really wasn't intended for heavy loads - it was designed for speed. I do believe that Carl's original idea of using wedges on the carriage plates to tension the carriage wheels is not as good as using eccentric bolts. I may actually go with eccentric bolts on mine.

Anyway, since you want to throw around heavy masses, why not go with a more conventional X-Y Cartesian design?

Also, if you are seeing twist with your loads, that means a part is flexing. It almost certainly has to be the carriage. A more rigid material or a beefed up mechanical design could fix the problem.

I've imagined the possibility of a direct drive extruder on a machine like this too. But I think I'd explore a lightweight pancake motor extruder design in an attempt to keep the mass down as much as possible..

The point for me is more about the challenge than about the end result. The sliding carriage met with mixed results and I decided to shelve the project for now. I redesigned many of the brackets and the results are pretty good so far: https://youtu.be/RUivslqPWQ0

Now my problem is that the steppers are slipping.. Not sure yet if the X/Y steppers are too weak for my setup or if there's something else.. But the stability of the frame is no longer the limiting factor.

KDan - in reply to spiffcow

Steppers are losing steps?
What is the inductance of the steppers? What size are they (length)? And what power supply voltage are you running?
If you want high accelerations without skipped steps, you need:
1) Low inductance motors
2) High Power supply voltage
3) Lowest rotor inertia possible (shortest possible motors that will have sufficient torque).
4) A stepper driver that can properly handle #1 and #2.

Don't get fixated on holding torque. The torque curve is far more important.
Lower rotor inertia allows a motor to accelerate/decelerate faster with less current.

Looks like you are only using a single central leadscrew the whole way to the back, Hmmm.

spiffcow - in reply to KDan

Here are the steppers I'm using:http://www.automationtechnologiesinc.com/products-page/3d-printer/nema17-stepper-motor-kl17h247-150-4a-for-3d-printer

I'm running them at 12V 1A instead of 1.5 to reduce heat. I have never heard to get short motors for that reason.. Would it be better to switch to NEMA23 for that purpose?

Also, there is a corresponding lead screw in the front.. I'm planning to put a second set of rollers on the front too, but haven't gotten around to it

The carriage can only move left and right, if the carriage is twisting then the wheels are too loose

balu - in reply to KDan

You are right, my comment with the "free hanging belt" was more of an aesthetic reason than anything else (besides not being sure if it'd compromise stability).

Does anyone know the weight difference between a V-Slot / wheels carriage and one with rods / linear bearings just for the X axis?

For rectangular builds I always wondered why people not use the shorter axis for the moving one to reduce weight.

Instead of just building my own, I keep thinking about changes and what difference they'd make... :-s

KDan - in reply to balu

I don't know about differences in weights between V-slot/wheels and smooth rods/bearings, but I can tell you the difference between using a 20x40 X-axis extrusion and a 20x20. I just weighed mine. The 20x20 is 222 grams - which is almost a half pound, That means the 20x40 should weight almost a full pound. I believe that a half pound reduction in moving mass is quite significant - especially when trying to achieve high accelerations.

Can you post your revised gantry parts as a remix? I've been wanting to use a smaller rail for the gantry and in the future reduce the wasted volume on the sides of the bed to make the gantry shorter

I don't like to release anything publicly until tested. I don't have a functioning machine yet. I'll send you a PM about this.
I had to make the carriage slightly wider in order to avoid interference between the belt clamp and the carriage roller bolts. This may reduce X axis travel very slightly (or maybe not).

Good idea, that was one of my plans for a dbot 2.0

I am also interested in these mass reducing mods! I think I will just continue the regular build for now though so I can understand the original concept.

Did you use V-slot profile. But I can't buy V-slot. then, Can I use T-slot (Basic) profile??

You have to use Vslot for the rails which have wheels moving back and forth on. Look at this build which uses Vslot and Tslot to possibly save money - http://www.thingiverse.com/make:203841

D-Bot Core-XY 3D Printer

Hey spauda01. I congratulated you for completing the Build Guide on OpenBuilds earlier. I had sent a message here a while back but seems like it didn't get posted.

Anyway, I was asking how much further would the Z Axis motors need to be if I were using a 300mm x 300mm (with mounting holes on 320mm x 320mm square) bed?

Also, I printed a few carriages and was trying them out, could you tell me exactly how tight should the wheels be? Like should the carriage move if I were to hold the extrusion vertically, given that the carriage is only the printed parts and wheels with no other weight attached to it?

Based on a quick center of mass calculation, 95 mm instead of 69mm should do it. Exactly balanced would be around 75 + 20 or so for wheel resistance and printed load. You can try this on your own by picking a reference point (back of the back aluminum rear beam for me and working out the sums of the mass of a group x distance to the reference in the y direction all divided by the summed mass. You can group items together and measure the distance from the center of the group. For instance, the four plastic pieces that hold the wheels and its' hardware was 269.52 grams. It is centered on the beam, giving a distance to the back edge of 10mm. Formula would look like ((m1d1)+(m2d2)+(m3d3)......)/(m1+m2+m3...)

That's some good mathing. The experimental approach also works well: assemble the Zplatform/bed and balance it like a seesaw on some thin ledge and move it back and forth until you find the sweet spot

The wheels should all be evenly tight, they should be tight against the rails but not so tight that they resist movement when the belts pull on the carriage.

I don't know where the motors need to be moved to for a 300x300 build, I've never tried it. That will have to be figured out for new builds

This comment has been deleted.
May 13, 2016 - Modified May 13, 2016

Did you use the M5 square nuts in the V-slot on a 45 degree angle or straight?

Thanks for updating the build document too!

They go in straight and they tilt a little bit when tightened

Do you mean it grips on one side of the V-slot, but the bolt forces it not to angle out of the slot?

I'm not sure what you mean. I should of said rotate, not tilt.

May 13, 2016 - Modified May 13, 2016
Helix70 - in reply to spauda01

Right, so the two opposite corners of the square grip the V-slot?

Thanks for that. I really appreciate you answering my questions.

I think my DIN562 nuts are at the lower end of the spec, most are about 7.8mm, and the slot is 6.25mm wide, so not much overlap. Yours look a little bigger, more like the 8mm. With a bolt inserted, i can almost get the nut out of the slot, if that makes sense.

I'm not a huge fan of the square nuts from mrmetric either, the corners that grip are only small and tend to squash the alu if done up tightly. I found these and they seem to work well, cheap and free shipping.

http://www.banggood.com/100pcs-M5-Hammer-Nut-Nickel-Plated-Carbon-Steel-Nut-Aluminum-Connector-T-Fastener-Sliding-Nut-p-1048442.html

You might be onto something there. Have you tried them yet?

I didnt replace any of the square nuts but for a drop in and as a square nut replacement, they work very well. I'll be using them to mount the electrics(ramps and SSR).

Thanks, I did order some, so I will have options. It is a frustrating wait now for all the parts to arrive! Got my E3D V6, V slot, nuts and bolts, steppers and electronics. Next week I get the printed parts. Waiting on the mini V-wheels, heat bed, bearings, extruder gear, belt, pulleys, glass, LEDs, power supply and now some T Nuts. I can cut my V Slot when I find a friend with a drop saw.

Can't wait to start building, this is the project I have been waiting for.

They are certainly not as tight as Tnuts would be but the good thing about the smaller dimensions is that they can usually be inserted into the side of the rail for adding components after the frame is already built which is helpful.

I can imagine, but with your fantastic build guide, probably not necessary! :)

Hi Spauda, I really like the build plan. I will be building one soon(with 300x300mm Print Area). The one thing I would like to suggest for the builders is try using Aluminium Corner Brackets as they reinforce the structure better and also withstand to vibration for a longer life and steady print.

http://autosystem.en.ecplaza.net/9.jpg

I just want to say, thank you for putting in the time and effort to complete and put this printer on Thingiverse! I will definently be building this in the near future.

What's the point of the SSR, to keep a minimum load on the RAMPS board for the heated bed?

The bed draws too much current for the ramps board to handle safely

May 12, 2016 - Modified May 12, 2016
dgcaste - in reply to spauda01

Ok. I noticed you have your 12V hooked up to both 12 and 24V pads on the heated bed. Is this more effective than just hooking up to 12V?

Edit: oh shoot, I'm re-reading the table and for 12V both are required to be hooked up to -.

Thats just how the bed is configured, check out the vendor page for the bed via the bill of materials

I noticed that in your build guide you include the glass bed with PCB heater assembly. You have said to either buy glass with notched corners or glass that fits inside of the PCB bed screws. What size is your glass plate then and/or why did you then use the binder clips? Thanks.

The glass is 12 3/8" x 8 7/16", the binder clips are required to hold the glass on the pcb

Thanks. I noticed in your pictures that the edges are rather curved? Can you explain how you did that?

Which edges?

The edges of your glass plate. They're curved to allow room for the screws?

I cut the glass corners with a tile cutting dremel. If you buy glass from a hardware store or glass store they might be able to notch the corners when they cut the class.

Nearly done building, I'll post a Make once I have it looking a bit better. So far, I have everything mounted and all axes have been tested and move as they should.

Is it at all possible to make an mk7 version of your extruder?

I see cfeniak has one, but it's mount doesn't play well with the D-Bot design.

It was not meant for the C-Bot (or D-Bot), but it's predecessor. To use a MK7 in a direct drive setup versus a geared setup you would need a huge nema 17 stepper as it has reduced mechanical advantage due to the diameter differences you mention. To use the MK7 with a standard sized stepper look for a greg's wade type extruder remix that can take a 5mm bolt instead of the old school 8mm setup.

May 12, 2016 - Modified May 12, 2016
Masterjuggler - in reply to cfeniak

I actually made a planetary gear box with a 3.8:1 ratio that mounts directly onto the stepper with a 5mm output. works pretty well. I know the mk8 is the "upgrade" to the mk7 due to the reduced diameter, but with the proper amount of torque, the smaller diameter is detrimental due to the reduced surface area contacting the filament, and makes filament grinding likely.

I could just modify someone else's extruder with the mounting holes for the tube holder, but I am not proficient enough with cad software yet to make the e3d bowden extras mounting hole.

yep, absolutely

Is it possible for someone to make an mk7 version of this extruder than can be mounted on the side of the extruded, and still accept the bowden extras that came with the V6?

Here are the original files (I thought this was linked as a remix here but it isn't). There is a 123D file there that you can modify the design to meet your needs. What you need to do is shift the motor alignment to the side the distance of the mk7/8 differential. Leave the filament guide pieces where they are. This one doesn't have the bowden mount sized, but is left to be drtilled out. I would measure the bowden extras and size it appropriately before printing. Give it a try and if you still need help let me know.
http://www.thingiverse.com/thing:456788/#files

Direct Drive Bowden Extruder; MK8 version
by cfeniak

It took some playing around with as I've never used 123d design before, but I think I've figured it out. Posted it as a remix to the d-bot and your mk8 extruder, and I'll get a pic or two up once I have it mounted.

Thanks for the help!

What is the difference between mk7 and mk8?

Mk8 filament drive gear has a 9mm OD, mk7 has 12mm OD. Basically, a tradeoff between torque and grip on the filament.

The mk8 has been working pretty well, I haven't looked into any other drive gears

I've found that mk7 gives a better grip on the filament due to the larger diameter and the greater amount of surface area on the filament. For torque, I made a planetary attachment for my stepper motor.

Is it possible to make an mk7 version of your extruder? you can see cfeniak's mk7 extruder here: https://www.thingiverse.com/thing:292437

The issue with this is the mount interferes with the gantry if I have it on the side of the printer, but doesn't look good if I mount it on the front, and I'd rather not have it on the back for accessibility reasons.

Direct Drive Bowden Extruder for 20 mm extrusion
by cfeniak

Would there be any negatives to cut the v-rails to the 300x300 size and only use the 200x300 bed? If I ever decide to update to a larger bed, I just would like to have that option.

You could if you wanted to, as long as you put the 300x200 bed toward the back and leave the extra room at the front you wouldnt need to change endstops or firmware dimensions. You would need longer belts. The only downside is the bed would be a little front heavy but you could move the Z motors forward a little bit to try and keep it balanced.

May 10, 2016 - Modified May 10, 2016
MoshiBin - in reply to h8tebringer

That's very close to what I'm doing now. I actually have a 300x200 heated bed, but 300x300 aluminium bed and 300x300 piece of buildtak. Not sure how to mount that 300x300 alu bed on the 300x200 heater but I'll figure something out. If you go with everything 300x200 but 300x300 frame you can just mount the bed with the 300mm edge facing you, and move the bed mounts closer. You'll probably also need to tweak the firmware.

Edit: Maybe also move endstops?

I tried to load my ramps board this past weekend but i cant find the marlin.ino file. Any suggestions? Thanks

Download D-Bot_Marlin.zip from the thing files page, unzip, open the D-Bot Marlin folder, then the Marlin folder, then open Marlin.ino

I dont know what im doing wrong ,but the Marlin.ino file is not to be found. I'm wondering if they have reconfigured the way marlin is layed out

Its just an Arduino file in the zipped folder

I have been planning on building a CBot for about 6 or 7 months now. I've had most of the Rails and parts for the build for quite a while.. had some problems with my printers and a heavy workload and finally I've gotten around to printing the parts. Kind of glad I waited because Carl reworked a lot of the parts to make them more robust and that is good because my build is going to be 12 by 12 by about 30 inches I think.I have settled on doing the dual offset screws on my Z axis.
On the CBot Extrusion calculator it mentions that I might have to lengthen the horizontal extrusions 20 to 40 millimeters if I'm going to use the offset so there stepper Motors will clear bed.
Do you have a more exact measurement of how much I need to extend the width of my cbot? Thanks for all the great work

My bed is 12" wide so you can look at the lengths I used for the Dbot frame

Do you run your parts fan and the extruder heatsink fan always on at 100%? Would it be better for the extruder heatsink fan to be powered directly from 12V instead?

The heatsink fan is on 100% already, it is connected to the 12v input. The parts cooling fan runs according to firmware, powered off of the D9 terminals

That's what I thought. The electrical diagram shows the heatsink fan and parts fan connected to D9.

Only the part fan is connected to D9- which is switched by the controller, D9+ is always on

The electrical diagram shows the extruder heatsink fan and parts fan red and black connected together, and both are connected to D9.

Look again

Oh, right you are. Switched negative. Sorry, should have had a closer look!

I have parts on order, looking forward to building this, it is a wonderful design. Thankyou so much for sharing.

Are you still working on the build guide? Any updates coming?

Build guide will be done this weekend, I hope

Right in time for my build this week supposing I get my SSR in.

:D

Thoughts about using a lightweight geared extruder (titan + pancake stepper) instead of bowden?

It's definitely worth a shot, I didn't want to do direct drive because of the motor that would be needed but I noticed in Tom Sanlanderer's Titan review he used a pancake stepper so it's definitely possible

I was actually trying to play around with this. I just bought a Titan for my current printer, but since I am building this bot I was trying to model a mount for a direct drive variant for this. The whole assembly is quite light with a small stepper motor it is doable, just haven't been able to design it in a way I know would work.

If you end up using the Titan let me know how it turns out. Ive just started ordering parts for my own build, and i was considering the titan as a way to convert this to direct drive instead of bowden.

How does your bowden tube stand up nice and upright? Mine limp and sags to the side...

heh...

Couple reasons I guess; the bowden tube comes coiled, depending on how the ends are rotated when installed it kind of wants to coil back up or stay in a nice arch. The black plastic tube is secured tightly so it keeps the bundle straightat each end. There might be just enough stiffness in the 9 wires bundled along with the bowden tube to keep it in a relatively straight arch

I want to build a printer for the first time and iam not decided yet which model to go for.The Ultimaker 2 Aluminum Extrusion 3D printer or the D-Bot Core-XY 3D Printer.
Are they creating the same resolution and print Quality ?
Your help is needed.

I want to make a larger frame and print area is there a calculator for this?

I just wanted to say a huge Thank You! What a great printer design. I really appreciate how much time and effort you've put into the parts, instructions, BOM, and helping people out. The BOM is oustanding - all of the prices and links must have taken a lot of time. I'm currently building one (using HIPS for the printed parts to save some weight) - may use one direct and one bowden into a cyclops head, but will proabably start with a E3D or Hexagon head and bowden first. I'll post a "Build" as it comes along.

Thanks for the thanks

Would PETG be ok for the printed parts instead of ABS?

I currently use a Wanhao Duplicator i3. I want to upgrade (build) to this.

I think PETG is the ideal material for making printer parts

Whats a general printing speed for this printer? My i3 prints pretty slow.

The Di3 prints slow-ish but is still good for the $$$. I have one and used it to print the D-Bot parts in PETG. I had to print at 20mm/s to stop the extruder from skipping. Still print PLA at 40-50mm/s.

60mm/s is a typical default speed, 100mm/s is possible if everything is well tuned and built

Look into using a 12x12 120 V AC heat mat, much lower current, no beast of a power supply needed

How would I go about powering an ac heat mat? Are you suggesting use two power supplies?

You would use a solid state relay to control the AC current.

You don't need a power supply for an ac heater, it is powered from the same input voltage that feeds into the 12v supply. I'll try to post a picture later

Apr 27, 2016 - Modified Apr 27, 2016

What modifications would need to be done for a 200x200 build plate? I have a 400W heater that I really don't want to give up. Would I be able to get away by simply shrinking the entire box in the x direction? Specifically shrink G,R,N,Q,L, and M. Am I missing anything?

I have an ATX PSU which I don't plan on mounting within the D-Bot itself.

You could build the frame as is and just use the smaller bed by sliding the bed arms in slightly, then you would just need to move the Xendstop bracket in and modify your firmware/slicer with the new bed dimensions.

The other option would be shrink all 7 rails in the X direction, G, R, N, Q, L, K, M by 100mm and use the extra railing length saved and make the build volume taller. You would need to reorganize the lengths in Fig. 1 to see how much you could increase the legs by if you reduce other lengths. If you choose that option you would need longer lead screw also.

What if the lead screw is only 300mm instead of 400mm? Would we apply the same principle by removing 100mm from A,B,C,D? Basically, making a mini-d-bot! :D

I don't see why not. There is actually a little bit of extra length in the current lead screws so if you went to 300mm lead screws you could potentially only have to shave off ~80mm (just a guess)

May 16, 2016 - Modified May 16, 2016
Truetek - in reply to spauda01

If there's a little extra, don't you mean we could take off more? like 120mm? Unless I'm totally misunderstanding...

Edit: Never mind, I just got it. :)

Maybe the 100mm would still be OK to remove, if we want to shrink the footprint even further. Guess I could start off with the 80mm reduction, then cut the remaining 20mm if it really bugs me. :)

I would go taller not shorter, if you are buying shorter lead screws it doesn't save that much money. Maybe I just like printing tall stuff

I'm just trying to reuse what I currently have into this design. Already got all the electronics, heated bed and stuff, but the sizes are all a bit off from the documentation. The bed is 200x200mm (arane already asked that), and lead screws 300mm. Wouldn't be expensive to buy 400mm instead of 300mm, but it is when you have to buy it again. ;)

Apr 27, 2016 - Modified Apr 27, 2016
arane - in reply to spauda01

Im tempted to go with option 3, shrink the bot, and keep the z axis the same. The area where I want this printer is a bit height constrained. I should be able to order less aluminum.

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Anyone have a link to a 300x300 heatbed that you've used for this build?

I went the PCB route and bought one from 3heatbeds on eBay: http://www.ebay.com/itm/251349600412

Did you mount the PCB direct to the rails, or did you mount a piece of aluminum on the rails, then mount the PCB on top?

I used the same mounts for the 300x200 build, cork on the bottom and a 12" mirror tile (with the corners dremeled off) binder clipped to the top.

I'm using a relay (not an SSR) and a 500W PC power supply to power it.

Controlling the bed with a mechanical relay might cause more clickity clack than an old timey telegraph machine

I had picked up an inexpensive 40A SSR and I got what I paid for: A not very functional SSR. :(
Since I already had several relay's in my garage so I just went with them. Maybe I'll try another SSR at some point.

Using bang-bang it's not too bad on the test prints that I've tried. The bed holds a temperature nicely and Repetier has some good settings you can tweak.

Did you heatsink your SSR or bolt it to an aluminum rail? They like to overheat sometimes. Bangbang mode will help there be less clicking

I did bolt it to the bottom rear rail.

Technically it was working, just getting extremely hot. When I measured, there was a 4V drop between the output terminals. That makes me think the SSR is not very efficient. :)

Do you have a link to the one you tried using? I'll try to help people avoid that type in the future if it's unreliable

Sure thing: The one that I purchased that I believe should be avoided is: http://www.aliexpress.com/item/solid-state-relay-SSR-40DD-40A-dc-3-32V-TO-dc-5-60V-SSR-40DD-H/1843309768.html

It was very cheap in both senses of the word. :)

May 6, 2016 - Modified May 6, 2016
nallar - in reply to remailednet

If you purchase another one, I recommend getting it from a reputable component supplier like farnell, mouser or digikey.

For example: G3NA-210B 5-24DC http://uk.farnell.com/omron-industrial-automation/g3na-210b-5-24dc/ssr-10a/dp/1181259/false

Unlike an ebay cheap from china purchase it won't be a fake, and will actually work at the rated current without catching fire.

edit: Please note the above component is for AC heated bed control. It will not work for a DC bed (uses zero current switching), and has too low a current rating for that anyway.

Good idea to use a reputable company but 10A is not quite big enough, the bed I am using is relatively lighter power and draws about 10A on ramp-up. It's best to have plenty of margin on the current rating for the SSR.

Oh, I got confused and thought they were discussing AC heated beds.

An isolated SSR is a waste of money for low-voltage heated bed control.

Get a buk952r8-60e logic level MOSFET, its on resistance is so low it won't even need a heatsink if the bed current is below 15A.

I agree but for this build the SSR is a little more 'idiot proof' with built in mounting holes and wiring screw terminals, hard to screw it up.

What power supply(s) are you using for this setup?

Just generic 12v power supply for the RAMPS and a 24v for the heatbed. Will use the SSR as well.

Can you provide a link to the 24v power supply that your using? Also, how did you attach the connector? Thanks.

24v - http://www.banggood.com/400W-Switching-Power-Supply-170-260V-To-24V-16_6A-For-LED-Strip-Light-p-998724.html

I havent purchased it yet, but have the 12v version. One thing I noticed with the 12v one is that the bolt pattern is different to the one spauda01 has posted mounts for.

12v - http://www.banggood.com/Wholesale-12V-30A-360W-Switch-Power-Supply-Driver-for-LED-Strip-Light-Display-220V110V-p-39987.html

If connector you mean by the SSR? Then the heatbed out from the RAMPS goes to the control point on the SSR and the 24v goes to the other side of the SSR and to the heatbed itself. The wiring diagram is in the files to download and will give you an idea of how its done.

Banggood so far have been fine for the stuff I have bought and free shipping to boot. generally 3-4 week or I pay an extra $6-15, depending on the product, for 5 day shipping. Cant complain too much about that.

I don't know why but even I built this printer using 16 teeth pulleys, GT2 belts, 5mm x 8mm Flex Couplings and 8mm lead Screw as described in BOM, to print the test cube 20X20 mm with the exact size, I had to change values of X, X and Z in Configuration.h with the double values as listed below:

define DEFAULT_AXIS_STEPS_PER_UNIT {200,200,800,138.4336}

I'm still working to modify the extrusion stepper value because I did't used the MK8 drive pulley but another drive pulley a bit bigger that I had already.

Did you set three jumpers under each stepper driver to enable 1/16 microstepping

Apr 27, 2016 - Modified Apr 27, 2016
stevan - in reply to spauda01

I set three jumpers under each step driver but I'm using DRV8825 so I guess I enabled 1/32 microstepping. With 1/32 microstepping can I get a good print quality or is it better take off one jumper to enable 1/16 and set the values to the default axis stepper {100,100,400}? In my case using DRV8825 with 1.5A stepper motors what is the optimal VREF to set on each step driver, 0.8V is ok ? The Z stepper driver is loading 2 motors so its VREF must be higher or not? Thanks for your help.

I don't know, I have never used DRV8825s

Do you have a list how many of each bolt, washer, etc we need in total and what lengths?

Apr 26, 2016 - Modified Apr 26, 2016
spauda01 - in reply to JonnayLin

Bill of materials, page 2

What extruder are you using on this build?

A non-geared bowden extruder

Your own design, or something you can link to?

It is just what was included in cfeniak's C-bot, the printer this design was remixed from

Has anyone thought of creating an enclosure for the D-Bot? I am running my printers in enclosed spaces with bad ventilation and would like to open my printers capability to ABS, PETG and other materials that produce harmful particles while printing.

Not too hard to do... I was going to use corflute.. cheaper than perspex

Enclosure: http://www.thingiverse.com/thing:67693

Filter: http://www.thingiverse.com/thing:125264

Enclosure for 3D printer safety
A replicator 2/2X air scrubber that really works..
Apr 22, 2016 - Modified Apr 22, 2016

I'm going to use this bed because its a damn good deal and i'm ordering a bunch of stuff from them anyways.m http://e3d-online.com/BigBox-Heated-Bed

Do I need to change anything besides the hot end, putting the fans in series and modifying the ramps board?

For those that did the 12x12x12, is it just as stable as the 12x8x12 flavor? Anything you ran into build wise that might differ from the 12x8x12 build?

A few people, including myself, are going the 300x300 bed such as bhameline but as he said, changing the z rod position is needed but probably not by much. Im still waiting on parts to arrive.. have the alu cut, parts printed.

You can also go the Triple C-Bot if you want extra support on the bed. http://www.openbuilds.com/threads/triple-c-bot.1255/

I'm going the original path and planning the Triple C if I need to go that route.

I have not built my 12"x12"x12" yet, but the main thing you have to change is the location of the Z screws. They need to be close to the center of gravity, maybe slightly back, to provide the most stable z axis motion.

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Spauda help me! My friend bad cuting all extrusions( not 90 degrees ) Can you recalculating for me new lenghts of extrusions? Minimum 2mm shorter each one. Please.

I need some more information about the installation of the chipboard tablet under heat bed to avoid bending. How did you fixed the chipboard under the heat bed, used some glue or only place it below fixed with some clips?

JB weld epoxy

So you just epoxy the cork-board to the bottom of the PCB?

Would you think some looped Kapton tape would do the trick well enough? I guess I am just looking for a less permanent solution. I am constantly moding my RepRap build and don't want to be stuck with a PCB that has a sheet of cork board stuck to it.

No reason why not.. or maybe find a high temp silicon that would be easier to remove than JB Weld?

Quick google...

Loctite Superflex Red High Temp RTV Silicone Adhesive Sealant
LOCTITE® SI 596™ Red High Temp RTV Silicone Adhesive Sealant makes gaskets that resist temperatures to 600°F (315°C) intermittent. Resists aging, weather and thermal cycling without shrinking, cracking or hardening. Fills gaps to 0.25".

I'm sure there are other alternatives.

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Should be mm

Hi all, I just finished assembling the D-Bot and I'm testing the motions, all is working fine except the extruder motor that never has any motion in any way I connect the 4 pins (green-blue/black-red) of E0 on ramps 1.4 board. It seems that is a firmware setting issue related to E0 but I changed the stock configuration.h only for the settings related to the full graphics LCD. My stepper DRV8825 and all the hardware is working fine because as test I loaded the Marlin firmware for MPCNC that I used previously and in this case the extruder motor is working as expected but when I re-uploaded the Marlin firmware published on here for D-Bot following the pins connection scheme, the extruder motor (Model 42HD4027-01) connected to E0 stop working. Any help will really very appreciated, thanks in advance.

Apr 22, 2016 - Modified Apr 22, 2016
Vlerherg - in reply to stevan

Is the hot end heated to at least 170c? The firmware will prevent cold extrusion and disable the stepper below that temperature. Try sending M302 to allow cold extrusion and then try to move (without any filament loaded).

Good thinking, sometimes the simplest solutions are the best

Many thanks for your precious advise, frankly I checked the extrusion motor only with cold hot end because I did not know about the hot end temperature prevention but I was almost sure the firmware could disable the extrusion motor for a reason that till now was unknown to me, of course this is a very useful feature. I will follow your instruction as soon as possible but I think using M302 will solve my E0 issue and finally get the printer works as expected.

Temporarily plug the extruder motor into the X motor slot on the board, try some move commands, that will tell you if the motor is bad or not. Plug your X motor temporarily into the extruder slot on the board, try some extrude commands, that will tell you if you potentially have a bad extruder stepper driver.

Thanks for your help, I tried to follow your instruction and the extruder motor plugged on X is working fine but X motor plugged on E0 is not working and the DRV8820 remain cold. I also tried to swap the DRV8820 from E0 to X or Y and I seen that it's not damaged and working. At this point seems that Ramps 1.4 is damaged on the E0 driver, but I cannot understand why E0 is working if Ramps is running a different Marlin firmware? This means that ramps is not damaged or not?

If you ran the E0 motor from the X socket and if you put the E0 DRV8825 into the X socket and it worked then that points to the Ramps board being bad, see if you can return or exchange it for a different one.

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Just out of curiosity, what control board are you currently using? i know you mentioned the RAMPS 1.4. Just wondering if you have switched from there?

Ramps 1.4

Nearly complete! The printer is essentially done at this point, but I am having a bit of a hiccup. I am able to move X, Y & Z independently using the manual controls in Repetier Host perfectly. I can home X and Z without issue. When I try to home Y, everything seems to go perfectly until it hits the endstop. The Y axis hits and stops like it should, but then the X axis goes crazy for about 5 second, erratically moving back and forth in short stutters and then stops. The printer thinks X is still at 0. I can use the controls to move X away from the 'new' 0 point and back, but if I hit home again for the X axis, it does not move and resets its supposed position to a new 0 point. Very strange behavior. Anyone have any ideas? I have had motors with wiring shorts on other printers I have built and those displayed erratic behavior, but it was consistently erratic. This seems to work fine until homing Y and then X takes a dump.

The only glitch I have noticed is that if I successfully home Y, and then try to home X, the printhead will not move sideways but it says X=0. Start by double checking your wiring and make sure you made the necessary changes in marlin, rep, and slic3r for your -Y homing change

LOL. Turned out to be an oversight on my part. The wiring was still set for Y-Max homing instead of Y-Mn. Moved one wire and all is well. Thanks again for your excellent variant on a great design.

Forgot about that, good catch

So what changes in dimensioning for the aluminum extrusions do I need to make this a 12x12x12" print area? What about a 24x24x24" print area?

Looking to build the 1 cu.ft one for me, and the 2 cu.ft one for my girlfriend's dad.

Something as large as 24" is going to need to be supported on all for corners. You'll want to essentially mirror the back of the bed platform on the front and then center the z axis screws (you might want to beg some beefier screws depending on how heavy the bed ends up). While I think it should be ok, you'll also want to watch the weight of the x axis cross beam, if it gets to heavy, it will have too much momentum and will have to slow down the printer, mess with the accelerations or upgrade the motors to NEMA 23s for the torque. Just some thoughts to consider.

Apr 20, 2016 - Modified Apr 20, 2016
Jo0 - in reply to bhameline

I got a chance to check out the updated c-bot page. Will definitely be rethinking some things about the 24 cu.in design. Possibly have a 4 lead screw set up with a motor turning two screws? I also need to figure out something for getting my own 24x24 heated bed made.

For the 12x12, its at the end of the build guide. For a 24x24, good luck.

So I think I want to go with a Silicone heater mat such as this:
http://www.amazon.com/gp/product/B011U7AYX4/ref=s9_dcbhz_bw_g328_i4_sh#Ask

I should be able to have it controlled from the SSR and wire it up to the printer board without any issues right?

Apr 19, 2016 - Modified Apr 19, 2016
spauda01 - in reply to h8tebringer

Pretty much the same approach except you need an AC SSR, not a DC SSR.
http://www.amazon.com/Industrial-FOTEK-Protective-SSR-100DA-control/dp/B017W7N7F8/ref=sr_1_6?s=industrial&ie=UTF8&qid=1461088088&sr=1-6&keywords=fotek+ac+ssr

I'm guessing you would glue the mat to an aluminum plate and sandwich that to glass.
You might need to double check that the thermistor that comes with it matches what is in the marlin config file.
I would also recommend getting an inline fuse for the AC heater too since it is 120vac rather than 12vdc just for extra protection.

Apr 19, 2016 - Modified Apr 19, 2016
h8tebringer - in reply to spauda01

Well to take some of the confusion out of it (and since I do already have the DC SSR on hand) they do have a 12v DC model @ 300W
http://www.ebay.com/itm/300W-12V-20X30cm-Silicone-Heater-Pad-3D-Printer-HeatedBed-w-3M-PSA-Thermistor-/281889548671?hash=item41a1ed297f:g:fxMAAOSwhkRWdPS5
That way I don't have to get an AC SSR. The PSU is rated for 30a so the possible max draw of 25a from the heatbed should be ok.

This is the last piece of the D-bot puzzle for me, I have everything else done and then I can begin to build.

You already have a good 10-15a in draw from the rest of the printer. And the PSU in the BOM can actually only handle 27a.

25A is huge (relative to the rest of the printer) and trying to get 25A out of a 30A supply when you haven't accounted for motors, hot end, and the rest of the electronics will almost certainly overload it. With that kind of current you also have to oversize your wires and make sure every connection is completely solid.

If I were you I'd go with the AC mat, swap the DC SSR for an AC one, they are only $10 or so.

Spauda how is stability of Z axis on this construction. Bed not thicks up on rollers?

Sorry im use translator. I mean skew of z axis. Smooth movement.

The Z axis is smooth. The wheels must be lined up correctly, which can take a few adjustments.

Hi! I have a few questions.

What measurements do the .stl files use?

Do I need anything beyond a bigger bed and longer rails to go to 300mmx300mm?

The power supply should be plenty to accommodate the large bed as well.

A few people, including myself, are going the 300x300 bed. I havent built mine yet but just the longer rails and bed are required.

You can also go the Triple C-Bot if you want extra support on the bed. http://www.openbuilds.com/threads/triple-c-bot.1255/

I'm going the original path and planning the Triple C if I need to go that route.

Hey, got a quick question. I finally found the time between work, kids and school to finish up my wiring over the weekend. I do have one question that came up during my initial motion tests. The X axis homes properly to the left, Z to the top, but the Y axis wants to home to the rear of the printer. I am using your version of Marlin that I tweaked a bit to suit, but made no changes to anything related to the motion. How can I get it to home XY to the front left? Granted, this is my first CoreXY, but I am very used to having my machines home front/left and already have my endstops installed and cannot easily relocate the wiring. Any help is appreciated!

If you moved the Y endstop to the front already then you need to change define Y_HOME_DIR 1 as mentioned, you also need to change Home Y to min in Repetier Host settings under Printer Shape and in Slic3r settings under printer settings>bed shape change the origin to 0,0. There is no functional difference in printing if you home to left rear or left front.

Apr 19, 2016 - Modified Apr 19, 2016
Masterjuggler - in reply to Vlerherg

// ENDSTOP SETTINGS:
// Sets direction of endstops when homing; 1=MAX, -1=MIN
define X_HOME_DIR -1
define Y_HOME_DIR 1
define Z_HOME_DIR -1

Taken directly from the marlin config from spauda01. If you want the y-axis to go to the front, simply change the direction variable.

Hello. Im completing parts for you printer. How many kilograms of filament needed for all parts with extra parts like cable chain etc?

What is the largest part/what size bed is required to print all of the parts? Sorry if this is covered someplace else, I haven't found it for this build.

May 3, 2016 - Modified May 3, 2016
spauda01 - in reply to barrj4

Largest part I believe are the rear corner brackets, a 10cm x 10cm bed would fit them

Thanks!

Apr 19, 2016 - Modified Apr 19, 2016
Chairman_Miow - in reply to Marcin1415

I used about 1.25 kg of abs to print everything out at 100% infill. I think that if I had no failures I could've done it in just under 1kg

I bought 1 spool of eSun PETG and was able to print about 90% of the printer with that. Then I needed to buy a second spool to finish the remaining 10%.

I think - if you had 100% success printing every item - you could probably finish it with a single spool. But, I had some print failures, so it took a little over one spool. I also printed everything at 100% infill...

I'm not sure, I printed out my parts over several weeks/months with different spools. Maybe someone who has recently printed all parts can weigh the total parts or report how many spools they used.

I ran my own calculations based on what parts need printed and the estimated length and weight they would take up. Accounting for support/infill, any rafts/brims/skirts, etc, plus Cura's ridiculously shitty margin of error, I calculated it would take JUST over 1 reel, but that was without the extras like cable chain and ramps box and stuff so figure 2 reels will more than get the job done, failures included.

The heat bed seems to be out of stock everywhere. Any alternatives?

Just about any 200x300mm or 8"x12" bed will work, possibly makerfarm

I found the mk2 available for $30. Besides the 24v option on the mk3, is there any difference?

I do not know, I think cfeniak has one

I think I'll go with the heated bed from e3d. A bit pricier, but it'll save me some trouble putting it together and prepping parts like the glass.

On a related topic, what is the purpose of the relay, as opposed to connecting the bed directly to the board?

The bed draws too much current and the connectors and copper traces on the ramps board cannot handle the high current. The relay controls current flow to the heated bed without risking damage to the ramps board or melting connectors.

Since I'm using the Duet 0.6, I brought the topic up in it's respective subforum on reprap forums. The duet should be able to handle the load without a problem, but I'm going to solder a 14awg wire between the power in V+ and bed heater V+ terminals to bypass the pcb trace. In case anyone's curious.

Also, regarding the mrmetric screws being out of stock, half the time the stainless screws are actually cheaper than the black screws, and may be in stock when the black screws are not. They also have the d-bot printer and the whole list of screws on their blog.

Please don't do that, a ssr is like ten bucks, not worth ruining your board over

Apr 18, 2016 - Modified Apr 18, 2016
Masterjuggler - in reply to spauda01

In no way does this ruin the board. All this does is add more metal to an existing connection so it doesn't overheat. If it turns out the wire isn't needed, it's easy to take back off.

Of course, I am not new to soldering, and am confident I can do this correctly. If anyone wants to do the same thing as me, better learn how to solder correctly first and know how circuit boards work so you don't screw up a perfectly good board. It's a big concern if someone's first time soldering is messing with an almost hundred dollar board, haha.

Reinforcing the traces isn't the issue, the switching transistor for the bed should not be trusted to handle 10A or more of current without overheating

Can anyone point me to a good guide for tuning retraction? When I print most things (see my build for examples), they come out great, but when printing something that involves a lot of retraction, the extruder jams and starts air printing. I've been doing a lot of googling and printing of calibration prints, but haven't had any luck so far. I'm using simplify3d and Cura. Thanks for any help.

If your extruder is jamming, it is either from retreating too far or too fast. Retract too far, and the molten plastic will solidify in the cold zone. Retract too fast and you can strip the material. For a bowend setup like this, a good starting point is 4.5mm. If you keep jamming, make is shorter, if you start oozing, make is larger. Also a 40mm retraction speed is pretty standard from my experience.

Hey Spauda01, I am having some trouble with crimping the wires. I am using the crimps you recommended and the fittings. Is the 22awg wire supposed to be solid or stranded. I have solid. wire. Whenever I make a crimp the wire either easily pulls out of the fitting or snaps off like it was crimped too hard. Do you have any resources you could recommend to learn how to crimp?

I used that box of assorted hook up wire for the items that did not have to move much, but for the others (bed, gantry, and hot end) I used silicone extra flexible many-stranded wire, which is much less likely to break with a lot of movement. I had to be able to crimp new connectors to use that wire. I did not have any luck with the tool listed in the BOM, and eventually bought a pair of Engineer PA-09's. They work great. There is a good video on youtube on using them. Most connectors require two crimps - one for the conductor and one for the insulation - the PA-09 does both easily.

I would definitely look into a stranded core wire. It makes a huge difference, or at least did for me.

This is kind of low tech but you could just buy a set of jumper wires with female terminals and just wire splice onto each jumper wire to avoid crimps altogether if you have solid wire http://www.amazon.com/40pcs-Female-2-54mm-Jumper-2x40pcs/dp/B017NDLWYY/ref=sr_1_2?ie=UTF8&qid=1460653670&sr=8-2&keywords=jumper+wires+female

I don't think thos