I switched to ovals about a year (I drill for myself). I have noticed that my spans seem to be a little more inaccurate now, especially my middle finger. My drilling angle is about 50 degrees (Right Handed), so if you look at my thumb, the top part of the hole isn't in the center of the hole anymore (on the drill centerline), it is actually to the left.
When you drill ovals, do you always measure your spans from the grip centerline, top of the thumb, to the bottom of the finger holes? I find that after the oval is drilled the span gauge kind of wants to slip to the left as I am marking the holes, and I don't always get a consistent span. I have seen a maximum error of about 1/16" in some of my spans.
I always drill thumbs first, as that is the way that I was taught.
Anyone have any suggestions, tips or tricks they could share?
Drew