Deep cuts fail

Hey I have some trouble with making deeper cuts or pockets in hard wood. It always fails. I wanted to cut a small box. I did 2 mm depth per layer and 6 mm/s feed speed. So far everything was fine. But always on one of the lower layer it fails. The CNC goes crazy and destroy everything.

My guessing is, because of small vibrations the toolhead hits at one time the material with his howl cutting edge. Am I right ? Do you have experience with deep cuts ? Is there a solution? Maybe special toolhead’s?



Got a picture of your machine? Also make sure the router is mounted perpendicular to the table. Any leaning one way or another will cause this.

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What kind of bit are you using?

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OK, I have to check again when I have repair my cnc. Last try killed the gantry.

I am using a 8mm (NL=26mm) VHM (full hard metall) bit. Special for wood.

We typically use 3-4mm.


Pictures are really going to help here.

Yeah, but pockets will take forever with 3mm. Still 8mm takes sooo long.

That depends on your CAM. You have to take such a tiny bite with an 8mm, you can deeper cuts with a 3mm. It is a trade off. You can use a 16mm as well but then have to take an even smaller bite.

I am using estlcam. I use the peel (schälen) strategy with 45% stepover. I guess at this strategy this is max., or?



I would think so, using a finishing pass of course. I bet you will find a single flute, smaller diameter will be faster because you will be able to do a deeper cut.


Even 6mm will help.

ok, good to know. How deep can you go per cut with a 3 or 4 mm bit ?

Depends on all sorts of things. 1mm-10mm, here is my best.

looks pretty good. few days ago I did a large cutout with a 3mm bit and 2,5 mm depth per cut. My bit broke:/