Polyurethane engraving CNC. Help

I engrave polyurethane wheels for skateboards. And immediately there was a problem. Burrs after engraving. I am adding a video (For some reason I can’t add the video) and a photo of the final result. Maybe someone will help how to solve this problem? Maybe add speed, or something else.
Wheels 99A hardness
I engrave to a depth of 1 mm.
I use a bit high-precision straight engravers.
I am attaching a photo of Luban’s characteristics.

I will be very grateful for your help.

More photos

More photos

If there is a burr, then presumably the material is melting - so try lowering the power. I recently did a test on acrylic with 25% power and it was a bit too hot. Between 5 and 10%might work.

I didn’t do it with a laser. This is CNC

I would think that tooling choice is going to be just as important in this scenario.

What are you using to engrave with?

I use a bit high-precision straight engravers. (Link on shop Прямые высокоточные граверы OZX, AOZX - Larsen Bit - AOZX3.0501)

Cutting rigid cast polyurethane resin - Problems and Support - Glowforge Owners Forum

This web page is suggesting that rigid polyurethane may be a bit brittle to machine without chipping.

This finer type of tool might have some greater success

engraving bits | McMaster-Carr

It also might be worth seeing how it works on the laser.

I’ll try a laser. Any tips on speed and power?

With acrylic filling burrs are not visible. But sometimes I want a clean engraving, without further painting.

Looks nice, but yeah acrylic is going to have different properties than polyurethane.

I didn’t realize polyurethane could come in so hard, we have some cast polyurethane tubes we use for something at work and they are more like rubber.

I have no guidence to provide on laser, other than there is software called lightburn which is going to be the equivalent to switching from luban to cura

Could try a second pass with a radiused or a 45-degree cutter to remove the burr, though that would probably make the letters less crisp than you’d like. Or use a smaller cutter and do an outline pass, then the larger cutter to hollow out the middle. Both approaches would require a tool change so not ideal.

Laser: I would start at 10% power, default speed, and default depth (0.6mm) with as many passes as required to get to full depth.

Thanks for both tips. I’ll try.

Might just want to repeat the exact same pass with same bit with the work origin lowered by .1mm.
I’ve found on quite a few materials that just running a final pass takes care of any little burrs or fibers etc.
-S