Hey! This thing is still a Work in Progress. Files, instructions, and other stuff might change!

LeXY - Core XY 3D printer - Laser engraver

by altrome Oct 25, 2015
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Hi. Great work!) What is the maximum print speed without loss of quality?

Hi, PLA-ABS 50-60mm/s without problems (0.1-0.2 layer height), filaflex 30 mm/s. Thx!!

Hi i have chosen to do a very similar, if not the same project for school but i have ran into a problem with the power supply because we are only allowed to used ones that are double nsulated and are Australian Complient. I have a solution to use a Desk top power supply inside a compact PC case (Which i have been told we are allowed) but im not sure how to wire it.
Would you have any solutions or wireing diagrams i could follow?

Sounds like you're using an ATX PSU. There's some information here:


Very useful link. Thx for your contribution!

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Gibts dafür auch eine Bauanleitung? construction manual?

Hi, there is no construction manual. I've no time... sorry. You could review the whole project at gitHub in some cases is better than any manual.


I want to build one but cant find the necessary hotend.
You mentioned one with the 3 srewholes on top. I think this one doesn't have it or am I wrong :

Hi, this is exactly the hot end I'm using right now, but unfortunately they are out of stock now... I'm thinking to change the design to a more standard one like the E3D v6 or similar, or maybe a bowden one, but it will take some time... stay tuned.

sorry wrong link

this one I bought. As I've seen on some youtube footage the screwholes seems to fit.

Mmmmm... I'm not sure that this will fit... If you see carefully the design, this is a bowden Hotend (BCN3D sigma uses bowden) and works at 24V... while the actual LeXY hot end works at 12V. I don't know what power supply are you using, but the ramps works with 12V as well... Be careful.

In case it will fit, I'm fine with 24V. 12V is much to slow in heating.

Yes, that's true... Can you share your experience, once tested? It would be nice to see if that Hot End fits and how it works...

Me again.
What diameter of self lubricating bearing are you supposed to use?
I got ID=8mm OD=14mm L=20mm nothing else I found is self lubricating. Your holes in all the carriages are 14.5 so a bit big.

How do you mount the extruder fan duct? the only holes there are around 5.3 mm so no M3 insert will fit.

Hi kev0,

Yes, that's exactly the same bearing I'm using. The reason to put 14.5 in the printed parts is because you need some room to insert them. Once they are in place, you block them by screwing the M3 bolts under them.

Regarding the 5.3 holes, that's the correct size that worked for me... the inserts diameter is about 4.7-5 mm, but these holes are printed transversely, so the size vary a lot, obtaining 4.6-5 mm, which is perfect for the inserts...

Hope I explained well...

Sadly my printer managed to print a 5.2 hole so I cant use the inserts. Btw wich ones did u use? the linked ones doesnt seem to fit regarding to a needed hole diameter of 4mm.
for me selfthreatening m3 inserts were fine.
And were do I need M4 screws and nuts? (like u listed them)

For sure. Tahnks for charing this great design!

could you be so kind and post a list of the necessary amount of nuts and bolts?
The holes for the M3 inserts are to large are you sure you mean M3 inserts?

Hi again Kev0,

That's a hard to answer question because, basically, I don't know it... When I started to build the printer, I bought a lot of nuts and bolds... and used depending on the part... I will try to make it, but it will take some time... sorry.

My build is nearly done, now I got some serious issues. The printquality is much poorer than on my printer before. I got big problems printing arcs. A circle isn't anything near to round. what could cause this?

Hi kev0,

I've not experienced that before... I remember once that I found a bearing with excessive friction, but that was easy to identify. I imagine that you have checked belt tension, axis alignments, parallelism between axis rods, frictions, and so on... but it worth to check it carefully again. Here some additional recommendations:

  • move the carraige with the hand, the movement needs to be very smooth, without jumps nor strange noises, while observing all the belt trajectory looking for possible strange behaviors.
  • put enought lubricant on all metal-to-metal contact parts, I use machine oil at smooth rods and grease at threaded ones.
  • ¿have you printed a cube and verified the size? Maybe this can give you some idea of whats happening.

Keep us informed about your progress. Good luck!!

Because of your too big tolerances around the 8mm rods and the 14,5mm in the XY claps everything is a bit wobbly. I needed to fix all these points. Now the printer runs perpendicular in the axis. The problem persists.
could you please upload a version of your marlin?
I tried every Steperdriver available TMC2100 and DRV8825 are the same. Belt loose, belt overtight, same..

I don't think that these tolerances cause the problem... but all is possible. As I said, once you place the bearings and tight the screws below, the tolerance disappears... my carriages are not wobbling at all. Printing ovals instead of circles, sounds more like a belt problem... but if you have checked it... I don't know what can cause this behavior. What about the sound while printing? Mine is really silent compared to my other printer a BCN3D.
Sadly I can not upload my marlin right now but as soon as I can I will do it.

Its relative quiet.
I tightened the belt so much it went off the ball bearings. so tgis cant be the source. I noticed a slight move in Y direction while X is moving. this doesnt look right. How do I manage to solve this? Is this behause of a difference in belt tension? I tried everything I could mention.

Mmmm.. ok... I'm aware of that to tighten the belt is the most delicate part.... I usually tighten progressively, alternating right and left. Between each operation I move the carriage to the max and min Y positions and I ensure there is the same distance on the right and on the left ( X perpendicular to Y). The optimal tension is not easy to be explained... not too tight nor too loose... I know that this is not the most rigorous answer, but I think it can help.

Sadly I have to say its a design flaw. Because I have to tighten the 14.5 mm holes of the x-carriage to 14mm the whole carriage got another spacing between the two x rods. Caused by this there is to much friction and I got some minor slipstick effect on the x-axis. All the other axis can be aligned but the distance between the x-axis are fixed by the xy-carriages. It would be nicer to have realistic tolerances between the rods/mounting points and the bearings/carriages. I'll try to edit your files to something like +0.1 in diameter. Hopefully this will do the trick. Otherwise I think the front left pulley holder must be stiffer, in movement it bends and the y-axis gets pushed down. I printed everything with 30% retangular infill. The other parts seem to be allright. Still a great design!

I feel bad that you have this problem. The design has been tested not only by me, but by other users with different printers, and none of the problems you have commented have been appeared before... really strange. I still think that there is some other problem that we are not able to see that is causing this malfunction, but we are focusing only in the effect not the cause. It's a pitty not to have in front the printer so we could investigate further the problem (personally is one of the best parts of the process of making/building a printer, but the most frustrating at the same time). I will be here to help you in all that I can, but with the information I have right now I can't go further. Keep us informed about your advances. Good luck!!

For now I solved the issue. To fix the slight missalignments I opened the Bushings with a 8F8 bore to have a little mor play. Its good now.
I got some problems with slight bended idler pulleys.I'll construct a upper supportfor each corner.
I made some mods of your parts to have a better fitting (e.g. M3 Nuts not 6mm, 5,5mm holes are the right ones).

The printquality is overall great!
As soon I'm done I'll upload some pics.

Hello, I love your design. I am working on renovating my CoreXY machine and it would be great if I could see some closer pictures of your transmission to help get a better idea of what I should do to improve my design. If it's not too much trouble could you please post pictures of the motor blocks, the corner idlers, and the gantry bearings? Thanks a lot!

Hi, sorry for the delay... I'll take some more detailed pics about the parts you ask for... meanwhile you can take a look at the whole CAD project. Follow the GitHub link at the description. Regards and thanks for loving LeXY!!

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i start to build it ☺️
but i miss some parts that you put pictures
how can i buy it ...

I can use aluminum profiles , as 20X40 , without changing the design ? Haa due to differences in the profiles , I want to leave all with 40 cm lengths.

I think so... If you maintain the inner of the printer with the same lenghts/widths there's no reason to change the design...

So you believe that the printed pieces , embedded in the profiles , no problem ? Thank you in advance for answering !

Hi Rodneynelly, I can't ensure it 100%, but my 1 year experience with the presented model is excellent, so I don't have any reason to think the opposite.

ok , thank you for answering my doubts.

What type of metals used for production

I suppose that you are asking for the structure... If so, the material is aluminum. Like your previous question, Please, be more concise. Thnx in advance.


Ahh, ok... I've printed with all kind material... ABS, PLA, WOODFILL, COOPERFILL... The most important part is the hot end, that must be an all metal one.

ok thanks so much

how can i make Printing Volume more than

Hi, sorry, but I'm not sure what you're asking for... Could you detail a bit more?

sorry again
i mean BUILD VOLUME how can i resize it for make a big size printing

the print volume could not be bigger than the actual... Sorry.

What are the requirements to make the printing be a larger sizes

Basically the structure... Bigger structure, bigger print volume. Of course, you need the steppers, belts, bars... Resized to the new structure size...

If larger structure and other parts of the structure .. Do need to change dimensional in codes ...

Only in the gcode generator not in the firmware.

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Is there some how to or step by step manual?
I think it isn't so hard to build but I would be so mutch easier with a small description.

Ahhh and nice work I hope my printer looks as nice as yours.

Hi, thanks a lot!! as I said in the last comment, I'm aware of that, but I have no time... This is one of my highest priorities in my todo list...

What about the hardware instructions, which piece goes where, etc.?

Hi, I'm aware of that, but my everyday work makes me impossible to work on it... I have no time... This is one of my highest priorities in my todo list... thanks for your interest!

Hi i am interested in buildig this and was wondering when you wiuld be uploading some instructions or the firm ware that you customized for this printer thanks

Hi rhk22, the only thing you have to do is download it from the official github repository (you can find it in the BOM), and then uncomment the lines marked as coreXY... that's all... Pay attention especially the endstops and the stepper direction...

Hey, very interesting and beautiful design.

How scalable would you imagine this to be? If i get it correctly All i would need for scaling this up would be longer smooth rods, longer aluminium extrusions and a longer Trapezoidal screw right?

Hi, Thanks so much!! this is a good question... XD... I guess you are right with your assumption but I would add some extra diameter to the smooth rods (10 or 12 depending on how big would be the printer) and maybe big motors would be better. I think that the rest would be nice..

Hello , congratulations for the excellent work !
It is a great printer! I decided to build one to replace my Prusa i3 .

I have only one question to ask you. The limit switches are installed where ?
the capacitive sensor is used instead of the Z-axis stroke end ?

I think one is installed under the " XY_block " piece , right?
The limit switch cables are constantly on the move , is that correct?

Thank you!

No leí tu procedencia, si puedes contestar en español lo prefiero!
El inglés no es mi fuerte!

Buenas! Muchas gracias por tus palabras!! en referencia a los finales de carrera, efectivamente el sensor capacitativo actúa de Final de carrera en sentido Z. Para X e Y son actuadores mecánicos que se encuentra, para el eje X, justo debajo del XY_block derecho tal como comentas, y para el eje Y se encuentra anclado a la estructura en el mismo lado derecho. Y si, los cables para X e Y están en movimiento continuo, pero si se dimensionan bien en longitud, no sufren en absoluto. Espero haber ayudado. Saludos

A partir de 2016 ..... ya lo estoy terminando, en 2018! :)
Espero empezar el 2019 con la impresora lista !!

Con ganas de verla!! Lastima que ahora tengo poco tiempo, ya que tengo mejoras pendientes...

Hi Alex,

Great job with your build! I'm interested in adding the laser module to my 3d printer as well. From your BOM you said to buy the FlexMod P3, on the seller's page it offers 2 options:

  • Interlock, output loop monitor
  • Standby loop suppression kit

Let me know which of the two is the one you used.

Thanks in advance,

Hi! thx so much!! the option I used was Interlock, Output loop monitor.

Very interesting design, i'm considering building a coreXY myself and this one is a serious candidate as I see it may be quite easy to enclose the printing area and make a heating chamber. 3 things (at least!!) I wonder :

  • are you planning to release the source files ?
  • I'm not familiar with the extruder : is it bowden, wade, anything else ?
  • are you satisfied with the printing quality and speed ? :)



thanks for your words!! Yes, I'm planning to release the source files at GitHub, but I'm not ready yet (and I need time... lot of time ;D ). The extruder is a direct dirve extruder like the makerbot one but with a different hotend. And regarding the quality and speed, I'm really sattisfied. There are no great differences between my other printer (BCN3D) and this one. I can't compare it with an other printer.


Ok great. please keep us posted about the source files.
I'm currently running my P3steel with AIO (allinone) hot end that has a J-head type of connector. I cannot find whether yours has the same type of connector and I'd like to stick to the AIO hotend. Hence my question about source files (and also because I can't find a coreXY machine that is really opensource apart from smartrapcore !)

Hi Adolph, the firmware is a standard marlin nothing special, just follow the instructions inside of it... For the Raspberry, as commented in the summary, I use the Octoprint, and also is very well commented in their site.
To control the G codes, I use both Cura or Slic3r.

...For the Gcodes generation for Laser engraving, I use Inkscape

Very Nice , but can you upload the firmware to control the rams and raspyi please and tel us witch program you use to control gcode for cutting