ok, first of all, what do you call right offset ? If I look from nock to tip, the vane goes from right to left.

The real problem I've been having is that every arrow one or two vanes aren't glued down all the way, meaning, the end of the vane usually sticks on one side, leaving a gap that I usually end up filling with glue.
It seems that even using less offset, that the straight clamp doesn't push the vane down against the shaft all along it's base.
So littlechief spoke of using a helical clamp, but what kind ? the right or the left one.....

F.