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BeTrue3D Printer build part 7 – CoreXY and Front Panel

CoreXY Setup

I’ve build a bunch of printers by now, but this is my first CoreXY. I had read quite a bit about it, and also looked at a lot of photos trying to figure out some nice ways to put on the belts.

What I entirely missed was the requirment that all belts, aside from the rear/far right on my printer, must meet the bearings at a straight angle, and leave it at a straight angle as well, which mine did not do (still don’t).


This led to some extra hours of tinkering, as I posted some photos online to get some input after my first draft.

I came up a piece of metal for each of the far corners, which I can tilt as needed, to make the inner bearings to line up perfectly with the X sliders.

At my first draft I also had the far ends (away from motors) in two levels, in order for the belts to pass each other.

I later learned I could twist the belts to make them cross on the same level. It is ok to make one of the outer corner idlers a tiny tad lower or higher to make a bit more clearance for the belts.


I have ordered some teethed idler pulleys with bearings in them, as I need 4 of those for the idler-posts, where the teeth-side of the belts are touching the bearings.

I’m going to design some sort pieces for the Y sliders to grib the belts coming onto them from the X sliders. As they are now, they are very far from a right angle on the bearings 🙂

Front Panel – magnets

I always close up my printers. Or semi closeup as I do not cover the top usually. This helps keeping a stable temperature in the now-chamber, and greatly enhance the print-quality. Also for PLA.

It also makes it possible to open windows right next to the printer, which is nice.

I cut up some acrylic plate I had to match the front, marked up 3 holes on each side, did a 3mm pilot hole and then almost drilled through using an 8mm drill, which fits the round magnets I have on hand.

Note: I use some old dull metal drill-bits when drilling in Acrylic materials. It works a charm without ruining it.

Don’t despair if you happend to drill all the way through.. I did it myself a couple of times.

Glue in the magnets

I’m using 2 magnets pr. hole, as they aren’t very strong individually. Put a tiny drop of loctite between the two and some locticte in the hole as well.

You can see how this one is drilled all the way through, so just make sure to get some on the edges.


And done

Here’s the final piece. 2×3 magnets pr side – you might wonder how it sticks to my aluminium case?

A few posts back, I put on some black glue-on magnet strips I bought for some PC Mod a few years back.

They are very weak, but enough for this job.