Skipping Steps

Hello all,

I’ve had 2 carves recently skip steps at the end of a carve which ruined the piece. I’m cutting hard maple, 0.020 doc and 100ipm with a 1/4" bit (upcut and straight). It seems to be perfectly fine through the entire cut (about 30 mins) until the last layer where it cuts through the bottom of the maple - literally the last minute of the carve. It starts to tear out and get some large vibrations then I skip steps and the cut either goes off where it doesn’t cut anything or it will cut directly into my piece. Im guessing the vibrations cause the bit to hit my material where it would take a huge cut and skip steps.

Any ideas on how I can avoid this tear out and vibrations?

My first thought was to add tabs to keep it more rigid. This helps but I still skipped steps and ruined the piece (although to a much lesser degree).

1 Like

The material might be moving as it gets carved out. If tabs helped that might be an indication of it. Do you have a picture of how you clamped it?

1 Like

Unfortunately I don’t have a picture, but I clamped it down the best I could (4-5 clamps all really tight). That is a good suggestion though. I’ve had the piece move in the past and ever since I’ve really clamped the pieces down hard. It could have been possible though that it moved a few thousandths and ruined everything.

I’m not entirely sure if the tabs helped, I also slowed down the feed on this one at the end near where I had problems.

If you have parts in your design that will be cut out, you could run a drywall screw through it and into your wasteboard. I use drywall screws more often than not with most things that I cut.

I’ve cut three more pieces without an issue. I tightened the clamps with an allen key, added more tabs, and slowed the feed down on the last two layers. Thanks for the suggestions!

I will try the drywall screws though in the future, good suggestion for large-hard to clamp pieces.