I'm also working on a derivative, based on Wolfstock (which is based on Kossel, which is based on Rostock ;)

Anyway, I've completed the frame design and I'm looking at the arms and effector, and I find that I don't quite understand the math. Rather than just scale the design, can anyone point to an explanation on calculation of things like correct effector diameter and rod length? Or am I approaching this in reverse? Do I use as-built values to tell the firmware about my geometry?

powder sintering (SLS) parts here:
http://www.ebay.de/itm/Rostock...

Does any body try to use the Ultimaker board to make one?

will you be posting full instructions on how to build this?
 

What if i wanto to make a bigger print area? What is the connection between the print area and the lenght of the rods??

Can you explain which bearing are used where in this model? I'm trying to build my own and am confused on the bearings in the BOM.

How's the new prototype coming along?

About Rostock and Sanguinololu 13b (ATamega644b), just two cents.

I got the jcrocholl-Marlin-9d96e51 compiled with
arduino 1.0.1 for Sanguino, with some few changes and avr-size -B
Marlin.cpp.elf shows text=47744 data=412 bss=5886. For arduinos, the
segment bss is SRAM and its above the 4k limit for ATmega644b

When
I look to .bss code ( avr-objdump -x Marlin.cpp.elf | grep bss | sort
> Marlim.cpp.elf.bss), the block_buffer was taking 4928 bytes of
SRAM.

Searching the sources, at compiler time, BLOCK_BUFFER_SIZE is "always" defined as 64 in Configuration_adv.h

So
just force BLOCK_BUFFER_SIZE to 32 to get avr-size -B Marlin.cpp.elf
shows text=47740  data=412  bss=3422, just in the 4k limit for
ATMEGA644B cpu.

Or use BLOCK_BUFFER_SIZE as 16 to get avr-size -B
Marlin.cpp.elf shows text=47740  data=412  bss=2190, confortable low
water in the 4k limit for ATMEGA644B cpu.

I can't try upload and full test, my sanguinololu 1.3b w/ ATmega644b and all parts for rostock aren't shipped and ready.

Could you check ?

thanks

Alvaro Barcellos

I'm in the process of building a derived Rostock - Rostock_KOM for lack of a better name.  It will be the same basic design with a taller (1M rods) and more rigid frame using partial walls on three sides (like Cyclone's) made from 3/4" clear poplar wood and angle aluminum for attachment.  The base, top, and print bed are 1" poplar composite plank wood, also very strong.  I use a very large 2' x 2' base to keep it stable with the added height. But the big difference is the print bed is floating and suspended from the top by the 1M steel rods yet restrained in place by the walls.  If I find the belts need extra tightening I will be able to turnbuckle the print bed down to the base, but only if needed.  The electronics will be mounted out of sight under the print bed on the base with a fan to keep them cool.  I'm waiting on the plastic parts and the rods to continue my assembly.  I'm video recording the process and will post examples and info on YouTube, and then the detail design and BOM here.

Anyone made a laser cutter based on this platform yet? Do want!

Can we use a Printrboard (from Printrbot) and upload your version of Marlin to it? (I'm somewhat of a newbie to 3D Printing)

If not, what type of electronic circuit should we use?

I noticed you talk about not needing a heated bed.

As an Ultimaker user who has added a heated bed to his machine, I have some good experience printing both with and without a heated bed. I went without the heated bed for a good six months, and never had adhesion problems. But after pretty much every print, the tape would get damaged. After a whil
e, I got absolutely sick of replacing that damn tape all the time!

When I heard parts just popped off of the heated bed once it cooled, I had to try it. I added a heated bed to my machine, and threw a piece of borosilicate glass on top (no kapton or anything). It was amazing! heat the bed to 55C an
d PLA sticks like glue. Once the print is done, let the bed cool to 35C, and with the slightest push the part just slides off.

Printing with a heated bed has changed my printing experience dramatically. I'm never going back to cold blue tape.

As an advantage, I can also print ABS, and I've found i
t handy to do so for certain parts (being able to smooth out ABS prints with acetone is nice). I used to be a firm believer in PLA, but ABS is nice too. I've currently got about 15lbs of each type!

So anyway, just wanted to share that. Also, I'm printing parts for this now! :)

I started collecting parts for one of these!

WAUW!!....A big shout out....All the way from Holland. I am completely new in this area but i recognise ingenuity when i see it!!

The last few days i'm finding out more and more about this medium but i haven't encountered this kind of logical effectiveness

in such a low cost range yet...Untill now that is...ha ha ha ha ha

I would really like to try and build this?.....Everything that a inexperienced nitwit like me needs kan be found on your page?

afther 4 hours

Got my parts im starting to build ;)

Well my build is complete. And finally I seems to have it working reasonably well.

Some mods I made were:

- Using EiNSTeiN_ heavy duty bowden clamps except I found I had to use Hose clamps to stop the PTFE tube from moving.

- Added 3/8 threaded rods in the back corners and near front axis ro allow me to easilly tension the belts

- As my rostock is a bit of a shorty height wise, I mounted the Extruder on a bridge under the top to reduce the length of the bowden. for me it is shorter than if extruder is on the side.

- Also because its shorter I used the extra smooth rod length as a spool holder wich feeds in from the top. I could store about 9 rolls up there if I wanted :-)

The reason I have not cit all the rods to length is that all I need to do is add longer belts and it can grow taller.

:) My blog: http://billdrostock3d.blogspot...

An interesting upgrade would be to add a tension sprint to the top and bottom of the parallel arms.

Hello together,

is it possible to built the Rostock bigger, as example 500x500 mm workspace?

I am planing to built it with other linear guide and aluarms with Igus.

Thanks :)

I print the pieces in PLA?

Hi guys!

How much infill should I use in printing these rostock parts? Thanks!!!

Arnold

Mine was up and running for a while but I had a small issue where the extruder would jam occassionally when it had alot to print. Not long after that the heat resister died. I dont think I seated it properly and it was not disspating heat properly. I didnt have a spare. I am waiting for more to arrive with more heat goo too. In the meantime I made a small mod. I found it difficult to really tighten the belts, you need 4 hands to add tention them and then tighten everything up, so I added threaded rods. Now I can just turn a nut to tighten them.

They ping like a bass guitar now. I also added a twist so the back of the belt goes over the bearings at the top. This definately gives smother travels.

http://billdrostock3d.blogspot...

My next mod will be to move the extuder. Mine is a slightly shorter rostock so I have my extruder at the top and the length of the bowden tube is about the same as if it was on the side and has to reach the far corner. But because my printer is shorter, I am going to mount the extruder on a bridge suspended inside the printer under the top, a bit above the home position. Being in the middle this shortens the bowden tube by almost 50%. I will try it in the next day or so and report if it improves extrusion/retraction etc.

Got mine build up now, except for the extruder, but I have some issues with the homing sequence. It does home tho the top end stops, but then when it should home to the bottom end stops it doesn't come even close there.

I made a video of the sequence: https://vimeo.com/47376929

Maybe someone has an idea or a hint what I might have done wrong.

Awesome design. This design and files print very well and easilly assemble with nearly no clean up. One only needs to drill out the 8mm for the bearings.

Question: Do you think, after your use, that the six bolts on the lower motor mounts which clamp to the steel rods would work fine with only four bolts, evenly distributed? That is - use two bolts on the motor mounts for each rod? The rods do not get much pull/push and the plastic holds quite tigh
t. Just a thought to lessen fasteners and keep the solid integrity of design.

PLA - ABS... To those that ask. Note that ABS is the plastic most all the other printed printers were and are printed from. So, if you wish to - print ABS. I think this is the first published printer mostly from PLA. Plea
se correct me if there was another. I do not have experience with PLA but, it sure seems to work well for Johann.

On the small u-joint parts. They can be printed without raft and no fan. Also, no blowing - ;). For my prints I did not use any raft or supports. But, I was not able to print the rods
because my Thing-O-Matics build platform is too small. I am using carbon kite rods. Looks very High Tech and cool still.

Hi Guys,

So I'm ordering wood for this project.. Will MDF work? Or will the heat warp it in time? :)

I'm printing! http://youtu.be/_05IaRwncgc

Hey guys, has anyone had trouble with the Airtripper Bowden Extruder skipping? :)

Does anyone have a idea when a kit wil be avialible?

maybe i can be reseller for the netherlands i would like to do that ;)

i would like to make a prototype to but it isnt realy affordable to do that becaus the shipments tho the netherlands by the various shops

i cant wait :-D

Greats from the netherlands

hello to all I have a big problem with the sanguino because I use a atmega644 sanguino but the program is for a arduino mega my question is how to charge to sanguino and wath is the modified program. :'(
&
amp;gt;:o

Oh, and those using carbon fiber rods and the jaws.stl...what are the lengths of the carbon fiber tubing you are using?

Anyone here make a hexagon cutout for the base? Happen to have it in a dxf format?

Hi Johann,

I still have one question, that is what about the rod lengths, because with the same rod length the platform hangs at the front?

is it ok to adjust the front and rear ones?
front a bit shorter like 2-3 mm and back longer by 2-3 mm..

Just wanted to let you know that my son and I got our Rostock up and running last night. We are still waiting on the arrival of the 6 linear bearings in order for us to finish up, but we did manage to get it moving just to test it. Video Proof! - http://youtu.be/jXXPKiYkMsE . FYI: Top and Base are Polycabonate, side is one piece bent aluminum. Filament spool reel is built into the back side with spare flange bearings. Arms are carbon fiber kit rod. - I'll be adding more images to my gallery over time - https://plus.google.com/photos...

Almost there.

Its all built and printing.. kind of. Retractions dont work, I have tried various settings but extruder seems to just stop rather than retract and then races forward adding more plastic. As a result there are blobs everywhere and way to much plastic. But its running at least. As I have excess rod length at the top I have added a bar to stop my filiament spools there. Will eventially add one to all 3 so I can keep my favourite colours up there. Pictures on my blog. http://billdrostock3d.blogspot...

Hi All,

Has anyone found a way to attach a RepRapPro style hot-end to this platform yet?

If not, I guess I will have to make my own way forward ;)

Hi Everyone, perhaps you could help me out. What size holes should I put on the plyboard? I'm currently making a layout for laser cutting plyboard (or maybe acrylic, havent decided yet).

Anyway, looking at the jig's stl it says its 4.4mm in diameter. I think that's too loose for the M4 bolts. Should I reduce my file to fit exactly 4mm? or just keep it at 4.4?

Thanks! :)

I have mine moving and homing and drawing with a pen. I could use some help getting the extruded working. Not extruding cold or hot manually (I read there is a bug that won't allow extruding unless movement). Also need to know steps per mm for the Mk7 modified boweden I tried 50.xx from MakerBot firmware. Stripping and not laying down enough. Also, does the tube go all the way down into the hotend part? It doesn't want to feed in well because the filament has to align just right otherwise.

If you need someone to make the parts for you, there is a Company called

Matterhackers that will print them for you. Don't forget to order the jig and other external parts that you may need before asking for the quote. They will need the Thingiverse page and stl name. Email michael.hulse@matterhackers.com

to get a quote.

When do you think the next version is ready?

I really want to start building the Rostock! :)

I'm thinking about using the Makerslide so I can make the machine more rigid. :)

It's moving! I've commented out the bottom homing code (Johan, how's your change coming along?), but afterwards all it does is move downwards with all three carriages. I can change the speed by going different lengths, but it never stops moving.

Does anybody have any ideas what could be wrong?

Hey I think that one could actually print higher than the rods with very few tweeks.

The idea would be to flip the delta upside down at around mid print. That could probably be done in software by raising the 3 carriages up to the roof, then, one at a time, lowering each carriage way lower than the end effector.

Of course the roof would have to be openned and the arms whould pro
bably have to be curved in order to provide clearance around the print.

Good luck on your project!

Great project! I'm on my way to building my own. I've printed all the parts and they look great.

I have a question about the smooth rod. If the belts are 762 pitch, isn't a 762 long smooth rod just short of the motor and idler ends? I'd assume they would only go halfway into the clamps.

Cheers,
Fred

Reprap forum hasn't emailed my confirmation so I am asking this here.

How have the users been mounting the heat bed? Element side up (side with led and wire pads)? It seems like this would transfer the heat better and not directly heat the wood. The glass can be offset from the front so it would protect the led's. Has anyone used insulation such as cork between the heatbed and the wood base or have they been all mounting directly?

Hello all. I'm new to 3D printing. I was about to start building a MendelMax when I stumbled on the Rostock.

I'm an Electrical Engineer of 29 years, specializing in embedded systems hardware and software, so building a 3D printer is pretty cool. I should be able to help with various firmware improvements, once I get something built.

I'm excited about building a Rostock prototype and helping to improve it, but I don't have any way to print the plastic parts.

Can anyone suggest a source who would be willing to print the latest design of the parts. I'd obviously pay for your time and materials.

Thanks...greg

Would it be possible to use a Printrboard instead of a RAMPS???

Ah, didn't know that. Thanks!

It would be cool if someone setup a Google Group for others building a Rostock. ;)

It would be cool if someone setup a Google Group for others building a Rostock. ;)

please dont use block capitols. it makes it difficult to read

The BOM is missing the quantity of penholder and jaws parts needed, is it just 1?

This is my first time compiling Marlin code. I will be using the Mega 2560 and the Ramps v1.4 board. I am also getting the "Reprap Ramps 1.4 smart LCD controller inclunding smart adapter" which includes an SD card interface. What MOTHERBOARD setting do I use? I set to 33 and enabled the ULTIPANEL / NEWPANEL and SDSUPPORT but I am getting an SDCARDDETECT not defined during compile. Also when I looked at the pins.h there are these options but doesn't mention 1.4: // uncomment one of the following lines for RAMPS v1.3 or v1.0, comment both for v1.2 or 1.1

// #define RAMPS_V_1_3

// #define RAMPS_V_1_0

Hi Johan,

I was looking wich motor goes on wich connection, but can't find it.

can you tell me please?

Johann, does the print circle for yours encompass the entire printbed, or are the corners left unused?

Hello Johann!

I absolutely love the inspiration you have caused in the community for delta bots! I built a small delta that was 2 dof x/y for plotting back in high school with erector set but never finished the firmware for it.

I am very interested in perhaps getting a little bit of help from you in building
a micro stock. I have a frame already built and if you could help me figure out some geometry I would truly appreciate it. First off let me show you the frame here
&
gt;
&
gt;

http://brainspl.at/microstock-...
http://brainspl.at/microstock-...

I am using a G10 CNC'd tricopter frame design of mine for the top and bottom frame parts and I am using microrax.com 400mm tall 10mm tslot extrusions for the uprights and will use 300mm long PTFE slid
ers for the linear motion. I also have some very aggressive 5 start lead screws I will use instead of belts. I have a heated build platform which is 120mm x 120mm.

Here are a few little pics of the ptfe slides and the leads crews I want to use on the towers
&
gt;
&
gt;

http://brainspl.at/microstock-...

http://brainspl.at/micro-stock...

Could you possibly lend me a hand in sizing the center carriage and the arm lengths? with 400mm tall towers and 300mm sliders should I mount the sliders all the way butted up to the top lea
ving 100mm under the slides for the arms to move on? And how large should the center carriage and arms be?

I am wiling to do the work and release all this design back open source if you can help me get a better understanding of how to size this little guy. If you like it I will even CNC a few of th
ese top and bottom frame parts for you and send you some 10mm microrx slot to build your own in trade for info on how to properly size this.

I can CAD model the arms and everything myself if you can help me with the size of the carriage, the lengths of the arms, how far apart the parallel sets of a
rms should be etc. I have 6mmm and 4mm square carbon fiber tubing with round ID hole for the arms and I have UV joints, Clevis's as well as rod ends and a few other nice hinges I can use on this little guys as well as a CNC milled center carriage for the extruder mount that will be *super* lightweig
ht allowing for a slightly heavier extruder perhaps.

Any help you can throw my way would be greatly appreciated. And if you can hep me properly size this microtock I will happily send you a set of parts to build this frame for yourself.
The radius of the frame is 110mm. So 110mm from the center of
the frame to the center of one of the 10mm slot uprights.

Thanks in advanced for any help with this.

I now have mine built. I am finding no instructions on how to wire it up. I have guessed and it seems to work (kind of) I assume min endstop is at top? If in Pronterface I home Z it goes to top. Moving manually in X Y and Z seems to work correctly most times. But I I try to print anything, it goes crazy does not seem to do the nice dance that you see in the vids where it goes down to the max stops, etc. Are there any pages that show this next step of wiring and basic testing and calibration?

Noticed some discrepancies in the rod files. Is it supposed to be 250mm long or 260mm long?

I couldn't get the rod.stl, which has some errors, to slice properly with Slic3r. So I tried generating it from the source, but the source configuration.scad lists the rod length at 120, which is clearly incorrect. But given the rod ends add some length, I wasn't sure if the correct value for the config file was 240 or 250. Or something else entirerly. Can anyone state for certain the overall length of the rods with the ends, and the correct value for the configuration.scad file?

Hello Im new to 3d prnter. Compare to other 3d printers..is this more expensive to make or cheaper? Thanks

do you have a list of the parts to be printed? (how many of each stl?) for some reason I can't find it :P

Yeah i like it i hope there will be a kit soon or maybe i can be beta tester ?

greats form the Netherlands

http://www.youtube.com/watch?v...
&
amp;feature=related

Before I ask my question, i simply MUST say that this is a simply amazing design !

Well, I was wondering: if I wanted to scale the x and y axis of the build platform to say 300x300 mm, how long do the diagonal rods have to be ?

How are you allowing for wear in the joints? As there are no bearings in the printed system do the threads form the screws cut into the printed parts?

I'm building mine at the moment and I am very excited about it. Thank you Johann for putting this together in a simple to understand and build package! 8-) I'll be posting my photos soon.

Johann, I would like to incorporate your Marlin firmware improvements into the Marlin/lincomatic fork. This will allow use of the Printrboard instead of Arduino/RAMPS1.4. Printrboard is an inexpensive ($130) board with integrated steppers based on Atmel AT90USB1286. Saves a bit of money. Have you
considered merging your code? I might be able to do this myself, but not sure on my capabilities since I am a beginner.

Regarding the rods; for comparison purpose I first printed a full rod in PLA and made a second one with the end_jaws.stl and a hollow carbon fiber kite rod tube. The PLA printed r
od weight is 13.7 grams each vs carbon fiber 3-piece rod at 7.4 grams each. That's 37.8 grams less weight for the 6 rods. The CF rods are also much stiffer than the PLA version.

The hollow CF pultred rod is available from goodwinds.com 60" x .188", part #020961 and is $7.79. This provides enough
for all 6 rods.

Thanks again, this machine is fantastic!

Just curious why a belt drive is used instead of a screw like on a desktop CnC? I would think that would be more accurate.

I'm a little confused *DONT_KNOW* with the wood pieces.

I see two different designs, and can not find the measures of the poliwood in the sides.

(appears that the hexagonal design takes more space)

could someone clarify the dimensions of the pieces of wood?

Sorry for my poor english.... :-[

Great job! :)

This is seriously a cool design. I'm building one as soon as I'm back in the workshop.

This is a fantastic AMF printer! :-D

I noticed in Marlin you are using the Ultimaker PID settings for you MakerGear Hotend. Are you getting reliable temps? I had to change this setting with my J-Head Mk V-B via M303

On average how much watts does the 3-D printer consume? For example how much did it consume (roughly) to print the owl model that is shown in the video

Is it possible to mount a cooling fan on the print head carriage, or is this not required any more even when printing PLA?

If Rostock loses power, does the print head fall down?

I built one, and its moving ;-)

now wondering how to calibrate axis_steps_per_unit, since X/Y/Z motion is not linearly connected to print head motion ?
(using T5 Pulleys with 8 teeth)

thanks for the good work

"I want to go there."

I have a feeling I'll end up making one of these in the near future, lol. :-D

You've got 1 pack of 10 608zz and 1 pack of 10 flanged bearings in the BOM.

How many bearings are actually used?

Wow look at all the Likers!

I'm building ---- Well I made my 12" (~300mm) rods longer to 17.9" (455mm). I then calculated a loss of useable rod at ~4" (~101mm) for base and end-stops. Then using a ratio of 16" printing to 30" height from your Rostock printer I calculated for my build [(16/30)*13.9] a print height of ~ 7.4" (
~188mm). This will printer will have 473+ cubic inches of printing area! This man's Rostock will be 8" (~200mm) X 8" (~200mm) X 7.4" (~188 mm). How many cubic mm?

Ordered are: motors and linear bearings. Stepper drivers are in a box waiting. Next is to decide on the hot end (buy or build or design
&
amp; build?) and which electronics. I've even got the LED lighting circuit nearly ready. Where will I cut my base? Will the plywood be swapped for acrylic instead? Ah, the fun of building. Excitement is in the build...... :-D Thanks again, Johann!

Wow. And I thought my Mendel was fun to watch. I think my Mendel electronics will be reborn as a Rostock.

This looks awesome! I'm feeling another build coming on.

How do you pronounce "rostock"? roe-stock, raw-stock, roz-talk?

This bot looks like something Dark Elves would make.

I'd enjoy watching it move even if it wasn't printing anything.

Amazing design. I am working up a design based directly on this, using most of the same mechanical design but modified to use Makerslide and V-groove bearings instead of smooth rod and linear bearings. That's mostly because I found a pile of small V-groove bearings cheap at a junkyard, but the Makerslide does have the advantage of being more rigid and has a hollow channel inside which can be used for routing wiring. One question - would you recommend 0.9 degree per step or 1.8 degree per step motors for use with this design?

A schematic diagram of the electronic connections would help! Please :D

The prints look fantastic, amazing job!

How is the dimensional accuracy as it stands?

I am having trouble finding the right information. I have all the parts and want to start making the top and bottom boards and mounting everything but I have conflicting size information on the various related Items. The the Idler end for rostock says to install the idlers on a plywood circle of 150mm radius but the PDF template elwhere had dimentions like 167mm. I am not sure which is correct or does the width not mater that much as long as they are exactly 120 deg

Please tell me you sell a kit somewhere!

I am in the process of building one of these. A couple of notes:

The specified GT2 belt of 762 teeth is longer than the theoretical maximum of 744 teeth that can be used with a 762mm / 30inch shaft (15mm idler and 15 tooth drive pulley). Long belts are only available by special order, and need to be slit from a wider belt. Best to use open ended belting instead
.

Currently redesigning the universal joints to use .75" PTFE or Delrin balls, and aluminum rod to reduce slop and wear inherent in moving a rough grooved part (screw) against a soft plastic part (PLA joint). I will post STL files when I have finalized the design.

Is the link above for Firmware: https://github.com/jcrocholl/M... the actual firmware you are using? Or do you have a more customized firmware?

I've got my parts printed and some vitamins on order. I need to finalyze what electronics I'm going to build and the motors to run. Pretty excited.....

Very nice. It looks like you are using the plastic as a bearing. Do you have any repeatability or backlash problems with that? Also, do you have an idea how it will wear across time? Great work - keep us posted with new videos.

Very cool. I'll be building one.

This has really come along nicely! Looks like you're getting good print quality too. Good job! :-D

How low do the carriages need to slide on the rods during the printing/operation? I've some short rods (300mm) and am thinking of extending them up several inches (75mm) from the base. *DONT_KNOW*

SWEET!!! Just noticed this thing was up and printing today. You have come a long way in 5 short months. Awesome Job! Fast, precise, and it looks good too!

:-P Well count me in too hehe... been printing the parts on my slow old printer all day.

This looks awesome.

12 joints. No jaws if you are printing the rods on an 8" x 8" bed. If you can't print something that big then use carbon or other tubing. You then will need to print 12 jaw ends to make 6 rods.

I can't print the rods on my Thing-O-Matic but, happen to have carbon kite tubes. You could go get metal hobby tubing also.

Johann this is excessively bitching. The maddest props are due to you!

Hmmmm.... am I missing something???

On the printed parts in the rostock-2012-06-29.zip how many of each part to be printed? Some are obvious but how many joints and jaws do I need to print for 1 on these printers?

Ok I couldn't resist making this thing after I saw how nice you got it working. Amazing job man, props!

Of course I couldn't just color within the lines and I happen to have these nice 900mm long CCM belt driven rails that can move at 1200mm/sec... so I am building my rostock, lock stock and smoking barrels like this
&
gt;
&
gt;

I'll post more p[ics here or on a "I made one" page this coming week when I finish. Can't wait to get this working, thank you for the design and opens cad too, rock!

Awesome work, Johann! Just about done with printing all the parts.

What length are the belt loops?

Hoping to help you out with some documentation as I build too.

I started to print the parts to built that nice bot.

Could you tell me what is the diameter of the circle where the vertical axis are positionned on? I guess the 3 arms are at 120° each other...

Thanks.

I would like to start printing to follow your lead. Would you publish a zip file of all the parts as STL files?

Your machine looks - GREAT! :-D

P.S. my machines are so old that their video cards will not support the OpenGL required to run OpenSCAD. :'(

Coming along really nice! Do you have a video of it in action?

Very nice, but the connections to the gantry carts should be hinged to move up during a collision. Then you can put a microswitch on each with signals fed down to the end effector. The weight of the end effector will hold the hinged plates down during normal operation. This way you can detect collisions with either the heated plate or the part you are working on to do an e-stop. It could also be used to calibrate the platform by touching down in a sequence of spots around the heated plate.

I've been thinking about your design for a while and the same problem on my Makerbot. You can't rely on a calculated value to prevent a collision especially in the absence of encoders.

May I make a request? It would be nice if your suspension rods could be made in 2 pieces for those of us still w
orking on a 4" bed or just the rod ends so we can use carbon rods.

How come you decided to build three towers instead of four? I downloaded the files from git and wanted to start printing some parts, but then I noticed that the main file("rostock.scad") has a 4 tower design.

Anyway, great work!

Interesting, but I think you will run into problems with vibrations and the overall stability of this design when you add the heavy extruder assembly.

I think you need to re-do your linkages, this seems like it can only go up and down with no lateral movement. =-X

Could this be accomplished with only 3 towers instead of 4? I know there is a lot of math involved using this method, would using less towers be more computationally intensive?