I Got That Wood Grain Pattern Again..............

[JoeLee]

Just a wild shot, could the 2" shell mill be unbalanced? Try mounting it between centers horizontally and spinning it by hand with no inserts. Does it come to rest at a random spot or is one portion always facing down?

I doubt it's out of balance, it's machined out of a solid piece of round and all the cuts or pockets are the same in size.
I think that trying to balance something so small in dia. by using centers would cause enought resistance to allow the cutter to rotate.
Perhaps setting it on parallel rails and seeing if it rolls would be a better approach to checking balance.
But on the other hand fly cutters with one tool hanging out the side aren't balanced either.

JL.......................

[Rosco-P]

I doubt it's out of balance, it's machined out of a solid piece of round and all the cuts or pockets are the same in size.
I think that trying to balance something so small in dia. by using centers would cause enought resistance to allow the cutter to rotate.Perhaps setting it on parallel rails and seeing if it rolls would be a better approach to checking balance.
But on the other hand fly cutters with one tool hanging out the side aren't balanced either.

JL.......................

Maybe it is too light to check static balance with home brew methods. Do you know anyone in the automotive machine shop biz that would static balance it for you? Is the face of the mill (and the bottoms of all the pockets) perpendicular to the shank?

If this is an import face mill, maybe you just got one of the bad ones.

[john hobdeclipe]

Question for the OP:

Is this pattern merely visual, or can you actually feel an unevenness in the surface?

[JoeLee]

It's mostly visual, the pattern isn't any deeper than your normal mill marks would be.
The shell mill is made by APT, I don't think it's a cheap import as I stay away from that stuff.

JL.......................