6 basic cuts commonly done with the Ellsworth gouge: scrape, roughing, push cut, pull cut, shear cut, shear scrape.
This is confusing for me as I don't see things the way a lot of other people do. I guess part of it is because I can do all of the above cuts with scrapers. To me, basically it comes down to bevel rubbing and non bevel rubbing, and those come in scraping cuts and shear cuts. Push/pull are variations of the same thing. Shear refers to angle of the cutting tool relative to the rotation of the wood. Scraper flat on the tool rest has 0 shear angle. Gouge flat on the tool rest, with the handle level and flutes at 90 degrees is the same thing. Drop the handle, and/or roll it on its side and you get a shear angle.
robo hippy
I don't think that your perspective on tools is all that much different. Maybe more to do with which tools you choose to use, but with respect to the relationship between cutting edge and wood not much different in my view.
Each of my bowl gouges has a slightly different shaped grind, but for most tasks, it doesn't really matter which of these tools I use. When one tools gets dull I pick up another and continue turning. I go by the relationship between the cutting edge and wood -- and maneuver the tool as needed to get what I want. It doesn't seem to matter if a famous named turner's grind is on the tool (however, it did before I got over the learning hump).
I do use jigs for gouges and an oval skew just because that what I prefer on the dry grinder and because they are almost essential on the Tormek -- the greater grinding pressure for slow wet grinding being the reason.
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Al, about your question, the only difference is that the slight offset with the Ellsworth jig does is make the angle on the wings slightly fatter. Think about it this way -- suppose that you had one of the wide CBN grinding wheels and the pivot point for your Ellsworth jig was in line with the middle of the wheel. Suppose that you were sharpening a bowl gouge and you had the gouge making contact close to one side of the wheel. Next suppose that you decided to slide the gouge over to the other side of the wheel. That is a difference of almost 1½ inches. How much of a change would you expect to see in the angle on the wing? For certain, there would be a difference, but at the same time, it is not too hard to envision that the difference is very small -- maybe a couple degrees or so.
When I was at SWAT, I saw that Johannes Michelsen had a new jig to put his favorite grind on a bowl gouge. It is somewhat similar to what I described except that the offset on each side of center for the pivot arm is much greater (two inches each way so the total difference between pivot points of the wings is four inches) in order to get the extreme rollover that he uses. I forget what the nose angle is, but it is somewhat smaller than the 60° angle that the Ellsworth jig normally is set. I bought one of his jigs because I had a couple of his bowl gouges from a couple years ago and wasn't doing a very good job of freehand duplicating his particular grind. Even with that much offset of the pivot points, the angle on the wings is not all that much wider. It does make the nose slightly more pointed the way that he prefers to sharpen, but then there is no reason that you can't put whatever shape that you want on the nose. I don't know how well that would work on all bowl gouges, but for his particular bowl gouge, it is great. I suspect that it might not be so good for a broad U shaped flute.
The Johannes Michelsen grind is the only one that I don't see as being an all purpose grind. I haven't turned any hats, but I have practiced a bit to try to have good enough tool control to turn stuff as thin as he does. I am still encountering problems when the wall thickness goes negative.
I should add that the Michelsen jig can also be used to put an excellent typical swept back grind on a bowl gouge by using only the center pivot point. If you set the nose angle to around 60° then it is just about the same as the D.E. grind. And, FWIW, it is a beautifully made tool.