First time I heard the beaver tooth angle, it was Chris Stott who said it, and I believe he had a beaver tooth with him to show it, or some one I saw had the tooth with them. I seem to remember Stuart making that comment as well, but that may or may not be true. Have CRS syndrome....
I have no clue about the 35 degree bevel being self feeding. Before I figured out that the 40 degree setting on my platform was actually closer to 35, and the 45 degree setting was closer to 40, I didn't like the more acute bevel at the 40 degree setting, it just didn't cut right, but made a fine detail type gouge. The only time I have experienced 'self feeding' is when trying that peeling cut with a gouge on the inside of a bowl. If you come off the wing bevel, you dig in very deep. I always roll my flutes over to about 3 o'clock and cut with the nose. No chance of coming off the bevel and getting that 'self feeding' catch. No clue as to why the angle settings are off. It is a protractor, and of course, 'it worked on paper'...
I have never considered scrapers to be self feeding, no matter what angle the handle is when the cutting edge is presented to the wood. I would suspect that it has more to do with bad tool presentation. On the outside of the bowl, you want to be at or slightly below center. On the inside of the bowl, you want to be at or slightly above center. What this does is that when you have a catch, the tool falls out of the wood rather than digging in deeper. The biggest problem, as far as I am concerned with catches with scrapers in bowls is using too big of a scraper. The main area where this happens is in the transition on the inside of the bowl. If you sweep across the bottom of the bowl, and come into the transition area, if you don't pivot the tool, you can end up with the entire cutting area of the tool being in the wood at one time. Basically biting off more than you can chew. I talk about that in my video 'Scary Scrapers'. I never use a scraper wider than 1 inch. I can stall any lathe I have ever turned on with a 1 inch scraper, as well as with a swept back gouge if I engage the entire wing. I hear the comment about bigger scrapers being used for 'less vibration/more stability'. If you want less vibration and more stability, move the tool rest closer instead of trying to hang out way too far off of the tool rest.
robo hippy
