Re: Glaser vs. Ellsworth
Lyn J. Mangiameli
>I don't own an "Ellsworth" gouge (neither the Henry Taylor or Crown versions), but I do have all the Glasers. The Ellsworth Signature Gouge jig video is my "bible" for bowl gouge use with my Glasers. So yes, I would say that his techniques are fully applicable to the Glaser bowl gouges.
The Glaser bowl gouge grind and the Ellsworth grind are nearly identical. Both use the same 60 degree front bevel angle, both draw the sides back approximately 3/4 of an inch on the 5/8 inch gouge, both put a convex shape to the drawn back wings. Basically with all of these side grinds, there is room for a fair amount of variation without drastically changing the overall cutting characteristics. John Jordan has a similar grind, but with flatter/straighter wings. I tend to extend my wings back a bit more than 3/4 of an inch and tend towards a slightly flatter curvature of the wings, but overall, I come very close to maintaining the original Glaser grind.
The biggest difference between the two tips and grinds is with respect to the flute shape. The "Superflute" on which the Ellsworth is based is parabolic in shape. The Glaser has straighter sides in an oblate V. My preference is for the Glaser (the John Jordan gouges, BTW, are midway between the Ellsworth and the Glaser in flute shape), as I feel it meets all the Ellsworth criteria a bit better than the Ellsworth gouge itself does. Specifically, David likes to talk a lot about "mass behind the edge." The Glaser V shape provides greater mass behing the edge than the Superflute (and far more than the U shaped gouges). The Glaser and Jordan gouges also have a narrower tip that I find superior for detail work. Finally, the flat sids of the Glaser bowl gouges are easier to maintain with a slipstone (the small one in the Henry Taylor two slipstone set from Craft Supplies is ideal). The Superflute is a good flute shape, though if you read the comments of the inventor of the shape, you will find that many of the intended advantages of its shape are lost with a swept back grind).
I wouldn't worry about 1/4 inch of extension one way or another. I use 2 inches with my Tormek jig, and use the same distance with my Ellsworth jig. However, minor changes will be accommodated pretty well by adjustment of the carriage angle. Of course you can not do this with the fixed angle of the Ellsworth jig, so it is wise to keep to 2 inches with it. The bottom line is that if you blacken the bevel with a magic marker and set you jig to allow the blackening to be equally removed, you will have an exact duplicate of the Glaser grind. You can achieve this on a variety of jigs, and I have been able to nearly perfectly duplicate it with a the Woodcut Tru-Grind, the Ellsworth, and the Tormek. Of course if you want to absolutely, precisely duplicate the very grind that Jerry puts on his tools, then just get a hold of him and he will is apt to be happy to sell you the very floor mounted grinding jig he uses to grind the gouges in the first place. Personally, I think your Varigrind will allow a near perfect duplication, as you have already found out.