[IJustWantToCutSigns]

Hello, I am an inexperienced cnc woodworker and need some help from you guys. The problem I am experiencing is having the bit drag on the wood and make the cut offset. I use an evolution 4 bobs cnc machine. I am only going down .03 inches into the wood at 70 inches per minute. Before the bit fails and gets offset it is running correctly and without issue. Please give me some recommendations and keep it vague (dumb it down) for I do not know these things.

 

[difalkner]

Which bit are you using? Got any photos of the problem? That always helps.

 

[IJustWantToCutSigns]

I dont have photos but I am using a 1/4 60 degree v-bit. It isn't a very visible problem you wont be able to see much. I am starting to think it could be something loose on the machine.

 

[difalkner]

What software are you using for your CAD/CAM? Are you able to see this dropping in simulation? A general photo of the machine, gantry, etc. will still help - someone might spot something.

 

[jw2170]

Welcome to the forum, @IJustWantToCutSigns .

 

[old55]

Welcome to the forum.

 

[maddog]

Check your collet on the stepper motor to make sure it's tight. It could be slipping allowing your Z-axis to drop.

 

[gwilki]

When you say that it is dragging, do you mean that it is carving the wood outside of the area of your intended carve? If so, how did you set your Z0? What is your safe Z height set to? Is the material perfectly flat?

 

[ken in minnesota]

dont bottom out the router bit in the collet, will get hot, expand and be slightly longer than cold.
could also cause it to loosen.

 

[Old Ray]

I had maybe the same issue after I had installed a new 60 degree bit. It was not the machine I run, a mill wright. It was me over tightening the new bit, which bent the inside of the collet enough to make it let the bit slide up and down slightly. You could not see it, moving, but you could fell it slipping pulling it up and down with your fingers I replaced the collet , everything is do great. Slightly warped wood will do it as well, not setting dead on flat. My latest creation was dead on flat piece of Brazilian cherry with Proverbs 3 verse 5-6 cut in English and in Ukranian. Both sides were dead flat which keeps me from going nuts .