Those work pretty good. Not perfect. I found that the angle it finds is sometimes correct, sometimes not. So I resorted to cutting several pieces and writing the angle of the cut on them. Then I would make one based on the Starrett and then fit up the samples I made. Whichever fit up best was what I would cut for that angle. Saved some frustration for me. More often than not, it would be a different angle by .5 to 1 degree in either direction. My samples were 41, 42, 43, 43.5, 44, 44.5, 45, 45.5, 46, 46.5, and 47. This made the angles visually come out better to the naked eye word.
mspart