Fuzzy Finish with Ballnose Tool in Plywood

Could be the bit is dull. But here's some advice on technique as well. May 13, 2013

Question
I cut a fair number of flutes in plywood using a 3/4 radius ball-nose. I'm currently using brazed carbide but wonder if there is a better option. I'm getting too much fuzz, but I suspect that it's because my tool needs sharpening. Would a tool with replaceable inserts be a good idea? Should I consider diamond? Can such a thing be had with chip breaker geometry?

Forum Responses
(CNC Forum)
From contributor G:
It is likely that the fuzziness is occurring on the climb side of the cut. If you do two passes, one direction and then go back in the opposite direction it will cut off the fuzz. Or, like you said the bit might just be dull.



From contributor D:
Try doing a final pass only taking off 1/32" or so. If you aren't burning, a slower feed helps, but mostly the material affects fuzziness. Birch ply usually has fewer issues than say, meranti. I have used inserts ground to a mirror finish and have found them to cut much cleaner as well. Maybe your sharpener could help.