Another Mostly Printed CoreXY Laser Engraver

Inspired by @mordiev’s Core XY 3d printing machine, I’ve started another CoreXY machine build of my own. Like Aaryn, I have a fair stash of parts and a Prusa printer always at the ready so I determined to try to adapt his design to use parts I have on hand, as much as possible. Not having appropriate length commercial rails in my stash, I’ve adapted and printed these BB-bearing rails and used some of the zillion or so 608 bearings I have on hand for idlers. I also had a few shorter 2020 extrusions on hand and have elected to use them, primarily just for support. Here’s the basic machine configuration so far…

I’m making just a basic CoreXY machine – probably just another laser engraver – as I don’t expect the printed rails would last too long in a 3dprinter. I’ll probably add the lightweight BB-bearing Z-axis from my rolling-gantry MiniFoamRipper machine and mount one of the little Neje “6W” (~2.5W) laser modules I have. Right now, I’m working on getting all the idler bearings into alignment and adjusting the printed parts to match.

This is just a fun project (NOT a serious machine!) to keep me off the streets (and away from those infamous women who want to frolic… :astonished:) but I want to say thanks to Aaryn for the CAD design (his Onshape skills are way better than mine!) and the inspiration to get off my duff. Thanks, Aaryn!

– David


Following this. How do you plan to keep the belt on the bearings?

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I’ll print little flanges similar to these I used on a previous coreXY build…

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3d printed linear rails?! Neat! How smooth do they roll?

That’s a good idea. I should have done that. I may have to copy that and update mine to use the 608 bearings.

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Not the greatest… but not bad either. Rolling them unloaded up and down the rail rapidly, they rattle a bit. But there’s a pre-load adjustment built into the carriage and moving at corexy speeds with a little bit of gantry weight and belt tension on them I think they’ll be fine. That’s part of why I wanted to do this project… I’m curious to see how the printed rails will do. I’m betting it’ll do better than most people expect… just as the printed R&P MPCNC setup did… :wink:

Here’s a little better picture of one of the rear idler assemblies from a previous build. The little flanges are simple to print and work quite well…


Making some progress!

Printing idler blocks and flanges…

Machine is starting to take shape. It will need legs or blocking up to allow for Z-axis but okay for now…

Matching up the upper and lower idler levels…

Checking ease of gantry movement over full range, front and back…

Front left motor mount…

Left gantry idler block and linear slide carriage…

Right block and carriage. The BB-bearing carriages have pre-load adjustment…

Right rear idler and spacer block…

Left side idlers…

Gantry at extremes forward and back. Easy movement over entire range…

Uh-oh! Lower belt path blocked by some of that nasty plastic…

I obviously have a few alignment issues to address before I can belt it up and test… but I’m reasonably happy with the way it’s going together. I think it’s going to be a neat little machine.



For a second I thought you were going to build a cantilevered CoreXY (confusing threads in my head).

Then I got to thinking, it such a thing even possible? A cantilevered system can’t be a true CoreXY, but it can use a similar spirit.

The X axis can be connected directly:

And the Y axis could be dependent on the X position:

With counterweights this could potentially be fast. The downside is that since it’s not a true CoreXY it’s going to require writing some code to get it to work in Marlin. Or I suppose the coordinates in the gcode could be transformed externally into individual motor positions.

It’s also I think possible to have a symmetrical range of motion with some additional pulleys:

This wouldn’t work for a printer, and I’m not sure about a laser, since the wires are not going to be happy crossing the X axis. But I’m thinking more along the lines of ZenXY where no connection to the head is necessary.

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I really like how you made the Idler sets so they can be mounted either direction. One universal part that can be used in many places. Very smart. I also like how those belt guides turned out. Since you have a machine that uses those same idler belt guides I wanted to ask if they cause wear on the edges of the belts over time?

Nice work.

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Dang, Jamie! I’ve got neck strain trying to keep up with all that… :stuck_out_tongue_winking_eye:

No, this is just a basic CoreXY machine, pretty similar to the one @mordiev has going in his build thread. I’ve adapted his design to use parts I already had on hand or could easily print and moved the motors to eliminate extra idlers… but otherwise it’s the same idea.

You could do a cantilevered corexy, I think. With something like this.


Thanks, Aaryn. I don’t have that machine anymore… I gave it away and haven’t seen it for a couple of years. While I had it I never noticed any belt edge wear however. I suspect if the alignment and belt tension are just right, it should last reasonably well. Replacing a belt shouldn’t be too difficult, however, should it ever needs it… :wink:

@jeffeb3 that’s excellent. I believe that would behave like a real CoreXY and CoreXY firmware would work. :clap:

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Just curious what filament you’re using. That white just looks so clean.

I actually like it a lot. I am trying to decide if there’s anything I can do with it. A pen plotter would be pretty fun. I don’t think there’s a good reason to make the zenxy cantilevered. But that would be fun too.

Blaine, that’s Sunlu PLA from Amazon. I’ve been using it for several years now and really like it. These parts are all printed on a Prusa MK3S printer. No machine failures or malfunctions due to filament so far…

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Too shaky now with pencil and paper… at a time when I was younger, smarter, and a bit more the “fashion hound”, I bought a pair of bright orange boot laces from the dollar store. Obviously a “visionary” as well :roll_eyes:… these now serve faithfully to help me visualize – and SWAG (Scientific Wild-A$$ Guess) – vital measurements, needed to CAD up parts for trickier belt routing cases, such as CoreXY.

Based on their posted artwork(?), looks like Jamie and Jeff might find this “tip” useful as well?

Just sayin’… :crazy_face:


Heh, I have a set of Kevlar boot laces on my winter combat boots. They’re quite bright.

There ya go!