All day I've been having problems with plunging bit!

[tbeaulieu]

I'm pulling my hair out! Staring at this project, I cannot see the problem! And this specific example is just one out of many "too deep" machining jobs today.

Elite.

I mounted 3/4 material on the bed. I have a DOC of .5 (Idea is to then plane it down from the under side) to get .5.

Zero the cutter with my block. remove block and issue Z0 to verify that it's at the surface.

My project is set to cut to .5 with 3 passes.

Start. Bit plunges to 5/8" !

I've exhausted ideas as to what this could be! Any ideas?

[MiloScott]

Have you done similar cuts without any issues on this machine? Same post processor?

[tbeaulieu]

HUNDREDS! I've also v-carved a bunch of stuff today w/o issue. It's only been this one project and only the profile cuts.

I will create a new project, copy just the outer vectors and recreate the toolpath to test. It's awful to destroy expensive material, not to mention machining time up until the final cutout.

[MiloScott]

How long is the bit that is plunging too deep? I see Z Gap of 1.5". Is there plenty of room on Z travel without hitting the high end?

[tbeaulieu]

The material is ply. Flat. I zero it, remove the block and hit z0. The bit goes to the surface. When i start the job it ramps down into the material WAY past where it should.

[MiloScott]

I downloaded the file. What PP did you use? Might be easier if you post the gcode file of the toolpath giving the problem.

[tbeaulieu]

Interestingly... I have recently replaced my PC! Perhaps it's related?

Here is the gcode. And thank you!!!

frame_Frame_1-4-Cutout.nc.txt

(4.69 KiB) Downloaded 29 times

[JeffZ]

It looks like your material thickness is only .5 in the gcode but you said in the first post you put 3/4 material. Could this be related?

[tbeaulieu]

Correct. For this cut I am milling as if it’s half inch and will plane after. As oppos3d to planing before.

[Adrian]

Can't see anything wrong in the basic g-code or in the file itself. I'd start looking for mechanical issues and/or issues on the control side such as offsets for that tool number etc.

Will be very interested to find out what caused it in the end.

[garylmast]

Another idea. Try changing the collet. I put a 3/8" bit in an OLD 10mm collet and it kept sliding out, causing it to cut too deep.

Gary

[dealguy11]

Collet and bit were my thought, too. If the bit is slipping out of the collet it can cause this, and once it starts to slip then the collet is toast. I usually replace both the bit and the collet in that situation.

[tbeaulieu]

Yup! You guys were spot on! The bit was slipping. All fixed up and cutting like a charm! I should have known that. Dope.

Thanks!