Minimizing tearout and chatter with rotary tool path

1

I’ve got a couple of rotary projects that need to be free of tearout and chatter. One is a wooden spoon that vibrates a lot (duh, it’s a long thin stick between centers :wink: and the other is a more beefy spindle. For non-rotary jobs I’d switch between right- and left- turning bits as needed to avoid splintering at corners, but for rotary? I normally use a up-spiral round nose bit for carvings but I’m afraid any bit of flex would cause an up-spiral to grab and splinter or chatter. Down-spiral round nose bits are rare, but I’m thinking a down-spiral doing climb-cut only parallel to the axis would be safest, if it cuts cleanly at the tip. For the spoon, though, I think it might be better to do rotary cuts from the tailstock to the chuck to maximize support.

Have any of you gone down this rabbit hole already? Any advise would be handy :wink:

2

I cut gun stocks on my rotary and use the rotary as an indexer, so no live 4th axis machining. Because of the length of the blank and to reduce chatter I support the material length with machinist screw jacks. They help a bunch to reduce the material flex and chatter. Just one way to deal with long stock cutting on the rotary axis.

3

Is that with an ATC, or multiple manually started jobs? I suppose I could add optional stops for adding/removing jacks, but I’m spoiled by the “push button get part” setup :slight_smile:

4

Manual change when time for the rotary to index. I break up programs to allow for the stopping, manually doing the rotary index and the resetting the screw jacks. All just part of more complex machining without full automation.