V Carve Pro - finish pass wider than roughing pass

I’m using VCarve Pro to do a roughing pass (.6 inches at .1 inches per pass, 40% stepover) with a bowl bit. Then doing a finishing pass starting depth .6, cut depth .05, 15% stepover.

For some reason, the finish pass bumps out about 1/16th wider on all four sides, so the bit takes a full depth cut…which gets pretty sketchy at the speed I have it running. Anyone ever encountered this and solved for it? The pocket ends up being 1/8th wider than I have programmed.


Is the finish program a pocket program or a one pass contour?
If it’s a pocketing program do you have a value in the pocket allowance field?

If it is a profile toolpath, do you have it set to inside and not outside or on?

I’m not sure my diagnosis is correct, but I did manage to eventually overcome this problem. It’s a pocket toolpath with no entry in the allowance field.

Instead of running the toolpaths at .6 rough and .5 finish, I changed it to .5 rough and .15 finish. Now, it doesn’t kick out the extra 1/16th all the way around.

The only explanation I can think of for this is that V-Carve is ‘allowing’ for that narrower portion of the bowl bit (doesn’t become full .75 until maybe 1/10th up). V-Carve doesn’t seem to be considering the I’m starting at .6, just that I’m only going .05.

Its weird, but I guess it makes sense in a computery kind of way.