Bit Not Following Toolpath

Hello, seeking some help.

I am having cutting failures on a cribbage board project.

The project is comprised of 11 separate toolpaths all of which work extremely well except for the final toolpath which is the cutout of the board from the wood. The issue is that the cutout always fails as the tools bogs down and loses its toolpath direction resulting in a ruined project. The cribbage board is oval in shape. The wood is .91 inches thick. I am using a ¼ inch, 2 flute, downcut bit at 80 inches per minute, plunge 30, DOC .125. The cut appears to go fine on the horizontal parts of the toolpath but struggles on the vertical round ends of the toolpath where the chatter increases and the bit begins to lose the path. Eventually on the second or third toolpath turn the bit bogs down and plunges causing it to wander off of the toolpath. The last attempt resulted in the bit being wedged into the router collet so tightly that I had to heat the collet nut to help me remove the bit.

I am seeking information as to what my issues might be and direction on how to correct them. Any help you can give me is greatly appreciated. I have a Shapeoko XXL.

The first thing to try is just a reduced DOC, maybe .08, see how that goes. Also check the pulleys on your stepper motor, make sure the grubs screws are tight and one is over the flat of the motor shaft.

Is your toolpath a contour? If so, you are cutting a slot (a cut exactly as wide as the tool), and that can be very difficult.

The usual advise is to instead create a pocket around your project that is about 50% wider than your bit (so in this case, say .350"). So it makes two passes around your project, and the worst case is a slot that is only 1 DOC deep.

HOWEVER, current versions of CC have a bug where pockets are cleared DEPTH first, so it ends up creating a slot, and then clearing the rest of the pocket. If you have it, I think previous version 729 does things correctly.


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