FB2020 CoreXY

by AxMod3DPrint, published

FB2020 CoreXY by AxMod3DPrint Feb 3, 2016


Note - there will be no further updates to this page. Any further updates will be on the FB2020 Github page - https://github.com/AxMod3DPrint/FB2020

Originally based on the Fusebox, this printer now has become a design in it's own right. Most major parts have been redesigned from the ground up or have been overhauled in some way.

Should you want to buy a full kit or buy the printed parts they are now available on


The Ethos of the Fusebox was to keep parts pricing low, which at the beginning of this project, was the same aim, however, it is now to improve the FB2020 to a point where it's pretty much it's fool proof and highly reliable. I want it to the point where anyone with a set of Allen keys can put it together. I'm happy with the frame rigidity, yes, it's not as rigid as it could be, but I still want to try to keep costs down where possible, by using printed plastic parts this helps a little. I've added a list of upcoming changes below.

All files should be orientated correctly for printing. Any file marked Culain is an original file from Culain's design and no physical changes apart from mirroring and orientating correctly have been made.


All bolt, rod and hot end holes on the STLS for the Carriage and Carriers have a 0.4mm tolerance. If you need less or more, grab the SCAD files. There is a setting in there to change it.

Belt Tensioning

The best way I have found is to loosen off the motors so they are on the end of the bolts in the Y direction. Pull the belts as taught as you can manually then tighten the motors back up to bring the belts to full tension. I'm working on a better tensioning system currently.

https://youtu.be/WNDfNemOfFM - Gayer-Anderson Cat in Whiter Generic PLA at 80mm/s at 0.1mm layer height.

https://youtu.be/yOhGpVYnDCI - Aztec Chief in ColorFabb NGEN at 80mm/s at 0.28 Layer Height

https://youtu.be/bmPf83OeyGA - Printing the Rigid coupler in ColorFabb NGEN at 80mm/s & 150mm/s Travel - retraction settings were being worked on, so the print is a little stringy..

https://youtu.be/XaOWR-UzrOI- 2nd Print - #3DBenchy Timelapse.

Print Settings

Printer Brand:



FB2020 CoreXY


Doesn't Matter








Print as orientated, Support needed for Extruder Carriage, Carriers, Idlers, layer fan assembly and right side idler rod mount.

All parts need to be printed at 70% infill for strength with the exception of the Bowden tube clips at 100% infill and RAMPS mount and Z endstop mount at 15-20%

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Can you make list of parts

There's a full Bill of Materials on the FB2020 Github wiki

anyone added bltouch probe mount to the carriages yet ? :)

EDIT: nvm I think this one will work :)


universal bltouch mount for E3D v6
by Rhuuk

hello! Do i need 2 lm12luu to attach the table? because lm8luu and lm8uu is for x and Y, yes?

Yes. the Z Axis needs 12mm Smooth rods so you need LM12UUs

Edit it in the description. Because I found it after buying another bearing

With regards to this, the proper BOM is on the Github.

Thank you! 4 LM12UUs?

I would get 2x LM12LUU, but yes, 4xLM12UU

Completed my build today, first print came out fantastic. Check the github for latest stls. However i changed a few things to make it more rigid, used pcb endstops for y and z, new slim e3d cooler / fan, bolted rubber feed for a safer and scratchless stand, side mounted open arduino mount for 2020 extrusion, silicone dampers for heatbed and Repetier instead of Marlin... now, only 2 30mm fans and 2 m2 screws are missing to get the whole thing completed. This gets my previous Prusa build a whole new life. Love this tiny gem. Btw. Go big and go for the Plus variant

Pics or it didn't happen :P

I found this page after starting to build the original FuseBox, and found I had spent £70 on the wrong kind of 1515 section, doh! 1515 is hard to find anyway, and it turns out there are 2 types, 1 that takes T nuts and one that takes regular M3 nuts (which is what the original FuseBox appears to be built of). Guess which type I bought :-) The T-nuts are stupidly expensive for the 1515 I bought too - only found 1 source, charging £11.95 for 25 drop-in T-nuts. So anyway, I'm starting again with this implementation, it does seem well supported too! This will be my first build, I have a Malyan M150 as my first printer, I'll be using that to print the parts needed for this one. Fingers crossed, I'll end up with a better, faster 3D printer which won't cost the earth :-)

Getting On OK with the build of this, just waiting on more slot-in T-nuts. More parts arriving today, the Arduino board and stepper motors should be here this afternoon :-) Just have a quick question about the thyristor for the heatbed. In the BOM it is described as "1x 100k 4.7k Pullup Thermistor - heatbed" Does this mean either 100k or 4.7k types are suitable?

Thanks for the quick reply. As you can guess, electronics is not my strong point, and I was a bit confused by the search results I was getting on the thyristor. I'll order one of these :-)

Good luck. You're best off grabbing the latest files from the Github, as I've just been tweaking a few things of recent.

Thanks, I'll do that. I'm already looking at that Github page :-) I'm looking to build the FB2020 Plus, as I want the extra height to build a P-51 flying plane from 3DLabPrint, and my Malyan's Z axis is too short by around 15mm. Ultimately I am hoping to add the Diamond 3 colour hotend to this, but I’ll build it as standard first, get it up and running, as I still have a lot to learn about building a 3D prnter. :-)

It's a big learning curve and I'm still tweaking these with small upgrades. I will say that if you get things right, they're highly reliable. The FB2020 was completed back in March, and rebuilt with current parts about 2 months ago after running about 2000, maybe more, hours, the only reason I rebuilt it was cracked parts due to wrong material choice. The Plus has been exactly the same.

I have my printer at the stage of adding the electronics :-) I have just had to design a new PSU bracket, as my 200W PSU is smaller than the brackets are designed for. Mine is here: http://www.thingiverse.com/thing:1969574. I haven't figured out how to round the edges yet, but I'll print it out and see how usable it is :-)

FB2020 PSU Bracket

Something I discovered recently when building the 3rd FB2020 is that the short piece that goes underneath the PSU holder isn't needed. I'll be modifying both PSU mounts to remove it soon, so it'll fit any PSU.

Hey Axmod, do u plan to add auto bed leveling to the printer?

No, there's really no need with the 3 point levelling as it's damn stable.

hey axmod, i figured out the belts and a few other things with the help of a fellow member here on thingverse who made ur built and also videos and tutorials, but i am still facing a few issues here. If you can help then t will be great.

the x endstop despite changing a lot of settings, reversing motors and connections is stll ending on top left corner opposite the motor despite actually ending at bottom right corner near the y endstop.

1)The printer is designed to home to Y Max. This means Y = 200 at the back left of the printer. If this is not happening you have your Motors plugged in incorrectly. All the motors should be plugged in the same way. If you followed the wiring guide on the Wiki you should not be facing these issues.

2) sounds like a Slicing issue.

3) Check the tightness of your belts

the 2nd and 3rd issue got fixed. Thanks for the help. but the printer is homing to y max but it isnt homing to x min.

its actually homing to x max on the opposite direction of xmin where it should be as per ur design. i have checked the wiring guide and everything else.

if i continue with this will it have any problems with the prints? y endstop homing at y max and x endstop homing at xmax on the opposite direction.

Swap the X & Y Plugs

Hey AxMod, my build is almost complete. Did not get time to make it earlier, had a lot of trouble putting the belts in as i do not have much experience with them, i think i did fine now. Now just waiting for the threaded rod to be delivered.

Can you help me with how to configure it on the ramps? i mean what settings and all do i have to put there, i understand you have given the gcode files on github but if you can just tell me how to put that it will a great help for me.

Thanks for the awesome files and printer!

Just fire the firmware at the RAMPS using Arduino IDE 1.64+ making sure u8glib is installed. No editing should really be necessary if you've got the correct parts. The only thing you should really have to do is set the Z endstop, E steps via EEPROM and level the bed. Also the LCD is set for a RepRap Full Discount controller. If you have the standard RRD controller you'll need to change that to make sure it works.

hey Sorry but i am a noob when it comes to installing firmware, which firmware are we talking about here to fire up? can you a detailed guide if possible? Sorry for the trouble .

I'm afraid I don't exactly have time for that at the moment. You may want to check Tom Sanladerer's guides on YouTube. The firmware is linked off of the main github page

ya i get it and i am sory to bother you again and again, but i have checked everything out but cannot figure it out. Can you just tell me 2 thing?

  1. how do have to divide the 3m gt2 timing belt, what lengths.

  2. when putting the belts in, 1 pc of the belt connects to both the xy motors or two of the belt pcs connect to x and y motors seperately.

thank you so much, that;s all i needed, somehow i missed this link. Thanks again for the support to this build.

Hey AxMod, i started printing the parts. They are coming out good till now. I am having major issues with one file in particular, its ALTERNATE BOTTOM BRACKET CULAIN. I have tried printing this file 3 times now and everytime after a few layers the top gets really uneven. It makes the print really rough on the top and unusable. The top layers are not turning out to be smooth after 4-5 base layers.

I have tried repairing the file with netfabb too but still no luck.
I am using the following settings to print this file:

Resolution = 0.2
infill 5 = 50%
perimeters = 3
raft= yes

Please check the file once.

thanks for you time.

Hi there, the file is fine. I have printed this very recently over the weekend without issue. What material are you using? ABS? PETG? PLA? This is more an issue with settings/the printer than anything else. You may want to check for partial blockages/do a cold pull. I'd also advise that any structural components are printed at 70-80% infill for strength and as little give as possible.

Hi, thank you the reply. I don't think it's a problem with the printer settings as i have been printing files non stop for the last 2 weeks. Everything has been coming out perfectly. I don't knows what's the issue with this particular file.

Just try other filament and try a cold pull, if it's been running solidly for the past 2 weeks it could be a case that you have a partial blockage, keep an eye on your temperatures while it's printing etc. Did you get the files from here or Github?

I downloaded the whole master folder from github day before yesterday.

Just run off a test print - worked fine https://raw.githubusercontent.com/AxMod3DPrint/FB2020/master/Images/20160512_100136_HDR.jpg

So it's either your settings, filament or printer.

what settings did you use?

My Standard 280 Micron layer height 80mm/s on the FB2020 Plus in eSun PLA. Think I left the infill low as it was a quick test of the model. Tbh, all that aside those settings aren't going to make any difference to printing the part. I'd try a couple of other models (Test Cube, #3DBenchy, I'm pretty sure it's not actually the model.

i understand that but just take at look at this print i just made


every other print im making including the other models for your printer are coming absolutely smooth and perfect. I am absolutely clueless why this is not coming out fine. If anyone else can also confirm it then i and you both can be sure. I am not trying to say your files are not fine, i am just asking for some help since you know the best about these files.

Hmm, give me an hour or so, I'll re-model it.

Thank you so much man, really appreciate it.

Done, print tested and working fine. It's a little larger as I've just noticed the end points were 15mm not 20mm. It was, after all, an original Fusebox part. This one's a little more slinky too, no more harsh corners. You may want to clone the whole repo as there's been a few updates in the last few days.

Thanks a ton. I will print it in the morning and give you an update. Cheers.

Hey, i just printed it, came out perfectly smooth. Thanks a ton for the rectification.

Not a problem - Just a note, I've just updated the Z Motor Mount ;)

Hey Ax, a little help here, not related to your printer design but if i want to just download the changed file from github how do i do that? i have to download all the files again and again as a zip for each changed file?

You'll need to download the ZIP file, that or install a git client and clone the Repo, you'll just need to issue a pull to keep things updated using the Git client

Hi, i am really interested in making this printer. i made a Wilson but for some reason i could not keep the frame stable. So, after a few months of scratching my head i finally disassembled it yesterday. i have about 90% of the materials needed to make this already with me. Can you please tell me how high can i configure this on the z axis? Whats the maxinmum length that u would suggest?

I have one here with 400mm Rods on the Z. However, it's sub-optimal. If you're going to build tall you need larger diameter rods, unfortunately the printed parts don't support it as yet. It's next on the list to do.

I have tried to upload the marlin file from the thing files for this printer but it keeps giving me error codes when attempting to upload to ardiuno mega. I don't seem to have any issues uploading other files. Any suggestions or updated marlin file?

Thanks in advance...

What version Arduino IDE are you using? You need to be using the latest version as Marlin 1.1 RC5/RC6 require it. Also you need to make sure if using the the Full Graphic controller you have u8glib enabled, if not, you need to select the correct display. Finally, the latest version of the configured firmware is over on Github at https://github.com/AxMod3DPrint/FB2020-Firmware

you should name this the pink panther.

awesome build ax

What firmware did you flash to your ramps board? I'm having some issues with marlin and getting my Y-axis to home properly. If you're also using marlin I was wondering if you wouldn't mind sharing your configuration.h file. As always, I appreciate your help.

If you have the Endstop at the back of the Bot, then you need to home to Max on Y. X0 Y0 is the front left of the printer. I've uploaded the latest version. It probably won't work out of the box as all directions are inverted in the firmware, so you may need to flip the connections

Hi AxMod,

Thanks again for posting your files and pictures. Three questions for you:

Are all of the belt clips on the carriage designed so that smooth part of the belt is against the teeth on the carriage?

I'm noticing that the M5x10 idler bolts are long enough go through both sides of the idlers leaving a pocket at the end of the bolt. Was there a reason for using short bolts? Have you thought about lengthening these bolts and possibly adding a nut?

You are not using anything besides friction, like a set screw, to hold the smooth rods in place are you? With my rod holders the part friction holds the rods place pretty well but when I tipped the machine on its side one of the rods slipped out. It feels like if a bearing developed any friction it would pull a smooth rod out of the rod clamp pretty easily.


The teeth need to slot into the teeth on the belt. There needs to be a twist in the outside length on the Y axis to make sure the smooth side of the the belts runs on the bearings. The short bolts were from the original design by Culain, yes they can be longer with a lock nut on the opposite end.

The rods are held in by friction. if they are falling out then it's a case the printed part will need to be printed with a little more extrusion multiplier to make it a little tighter for the y rods, the carriage ends can be tightened up by using the SCAD files as there's an option there to add or remove extra diameter. once the belts are on and tightened it pulls the carriage ends in every so slightly which will increase the friction on the rods, the same goes for the y rod ends, mine are loose enough to slide the rods in with a bit of friction and to be able to line them up, but tight enough to keep them in the holes.

Thanks for the reply.

Could you post a couple of pictures of how you route the belts from the carriage to the carrier?

I think I have done something different: On the carriage I have the smooth side of the belt against the teeth so that there is always a smooth belt against the bearings on the carrier or corner idler. This is working ok, the X and Y movement works fine, I made a few dry runs. The problem is that I'm not able to attach the X axis limit switch because it is fouled by a belt. So, I know I must be doing something different.

Images uploaded as requested. :)

Hi AxMod,
It looks like you are getting some nice prints. Thanks for adding pictures of the parts and the assembly, they are very helpful, keep them coming.

I notice that you updated the Thing Files a couple of weeks ago with some redesigns and an extruder.

Are all of the files there for a full build?
Do you like the fan duct you are using? Has that .stl file uploaded?
Are you happy with the designs, do you have any modifications planned?


The design is pretty much final. The tweaks to the extruder carriage were mainly just to tighten up the belt clips and allow for printing tolerences in the hot end mount and clamp.

All files are there for the build, with the exception of the E3D fan assembly. Which you can download from the thing page. I'm considering modifying it to remove one side of the mounts as it fouls on the leadscrew and changing it so a long bolt holds it on over a cable tie.

I'm still trying to pin down settings so print quality isn't as good as it could be.

Hi again AxMod. Just a quick question on the timing belt. Does it definitely need to be 3 meters long or would 2 meters suffice? My wait time from Amazon for a 3 meter belt is about 2-4 weeks. Thanks again.

The belt runs are just over a meter so yes, it does need to be a 3 meter length. You're better off ordering from a dedicated online store than Amazon, you'll get it quicker.

Hi AxMod,

It looks like you made an effort to design and orient the parts so that they would not need supports, thanks.
The Thing Details lists "Supports: Yes"
Any guidance on printing the parts?
Are you printing in PLA or ABS?
Have you been happy with the strength of 70% fill?

There's instructions on what needs supports in the info. As for guidance, all parts are printed at 0.28mm layer height. The Parts are a mix of ColorFabb NGEN and eSun PLA. 70% infill is more than enough. There are some structural parts that are printed at 50% on it as I forgot to change the infill and they're fine. Things like the RAMPS mount, Z endstop and spool holder can be printed as low as 10% and be fine.

Thanks for the details, much appreciated.

Congratulations AxMod' things are looking good.
After getting it running what fine tuning or design changes are you planning?
Thanks for posting pics of your calibration cube even though it is not perfect. What do you think is the cause of the banding you are seing?

Thanks. 3 Point levelling is going to happen, the 4 point is driving me nuts atm. Not sure what's causing the banding atm, although it's a lot better since I've made a change to the belt configuration and tightened them up. I've put a twist in along the long Y run on the outside, so the smooth side of the belt runs along all the idler bearings. The Extruder Carriage needs updating to match the the teeth of the belt. I ran a Yoda bust overnight and it came out really well and I've just run a couple of Marvins off just now which have come out brilliantly. There's still a bit of banding, but it's a hell of a lot better. I'll be posting pics later along with more updates.

Looks like nice progress. Keep up the good work.

Hello again. Have you included the pieces that allow for mounting the smooth rods of the Z-axis? I can't seem to find them in the list.

Apologies, seems I've missed them. There's going to be a large update today as it's now a fully functional printer.

Again, thanks a bunch for this. I'm in the middle of building and should probably have it done by tonight! I'll post pics once I do. Cheers!

Awesome. Be good to see another FB2020 running. I will say that if you've built to the same dimensions as this one a 300mm leadscrew is too long as it fouls the extruder carriage, I'll probably be changing the vertical frame lengths to compensate for that and to allow for a larger build volume..

I'm actually reusing parts from my QUBD TwoUp so I had to order vertical frame pieces to accommodate the shorter Z smooth rods and acme screw. Hopefully it works out the way I measured otherwise I may be having to cut into some pieces.

Comments deleted.

Not too sure what you mean. Can you give a little more info?

Nvm, I looked at the system a bit closer and it wouldn't work. Thanks for all this, by the way. Can't wait until I have it built.

Comments deleted.

Nice job. It looks like you are coming along nicely and are making frequent updates.
How close do you think you are to being "done"? Do you have a running machine or is the design still in progress?


Funny you should ask that, I have a moving machine, I'm just trying to get the motors right at the moment. There are a couple of pieces that I haven't uploaded yet as they need a quick test. The new front bed holders have been tweaked and there's a tie piece for the front of the bed. I'm thinking it'll be printing in the next couple of days..

Good luck. We are looking forward to seeing it run!

It's running now, I'm just about to do a load of updates to the Thing page

Looking forward to building this, keep up the good work.

It is a beautifull design. The use of 20X20 profile is a simple way to reproduce it in a simple way.
Could you give us the length and number of these parts please.
Thank's a lot.
Bestr regards.

Bill of Materials now added.

Nice work. Keep it up.
I was looking for your BOM but did not see it. Am I missing something?

Scroll down the thing details page..

Hi, I'll be putting up a Bill of Materials soon.

nice designes. do you have your fusebox assembled and tested? how does it work?
i still haven't started building it myself :(

The frame's pretty much done, I'm waiting on China to re-open after the new year celebrations to get the rest of the parts, only thing I've not ordered are the 3 stepper motors, I have a spare hanging around, and the E3D Lite6. Steppers will be bought next so I can get movement running. I'll hopefully have it moving by the end of the month depending on the post from China.

Was a little worried about the Z Axis not having enough strength, but in the frame it's fine, by the time it's got a plate on top, it'll be nice and rigid.

have you tested your coupling? i don't think it will clamp both rods concentrically to each other.

Test fit the coupler earlier, seemed to work fine, put a smooth rod in (leadscrew is still in China and it's Chinese New Year) and it seemed to line up correctly, albeit needs a slightly different plastic other then ColorFabb NGEN as it's a little too rigid, will check in XT later on.

For the Z or the Carriage? Carriage is fine, will find out about the Z when the parts come in..

i mean the coupling for z-motor and threaded rod.

Ah, I need to learn to read.. It's based around the Z Couple for the Mostly Printed CNC, and the better Aluminium clamps which clamp in the same way, so should work.

do you also publish the scad file?

SCAD file for the Carriage is up now..

I will once it's confirmed working and I've tidied and commented it up.

nice design, may i add it to my printer?

Quick one, discovered the extruder carriage doesn't work with the existing Y carriers, you'll need to use my carriers if you want to use the extruder carriage..

Bed holders are now reworked as well.

Yup sure. It's currently printing on one of my Migbot Prusa i3's, I'll post up pics when it's done.