Gordon Seto
06-17-2008, 1:19 AM
I believe there are a lot of turners who are confused with what shape bowl gouges they should get. In the past, I think we have been thinking too much about the difference in steel and have the impression that all gouges of the same material are the same. Same brand gouge of different diameter has totally different flute shapes. The Crown Pro PM ½" flute is tight V, while the 5/8" is open U. (All the dimensions are using American Standard, the diameter of the bar. The number on bottom is the diameter of the gouge shank.)
http://i118.photobucket.com/albums/o83/gbseto/b688d4af.jpg
http://i118.photobucket.com/albums/o83/gbseto/5aab1c59.jpg
I have quite a few bowl gouges before I discovered Thompson Tools. Since they all grind at an angle, it is difficult to distinguish the difference in flute shape. I made some wax mold of each gouge and scanned them with a flat bed scanner. I was surprised they also get the 3-D effect in pictures. From the pictures, we can see the difference in flute shape are obvious.
http://i118.photobucket.com/albums/o83/gbseto/ae7dfc00.jpg
Gary Guenther (GaryG in MD) has approached me and suggested he would write an article summing up the collective wisdom from posts regarding the effects on flute profiles. We hope this will generate a lot of subjective comments so we can all benefit from the findings.
Gary has two PSI Benjamin’s Best LX230 5/8” bowl gouges; he is going to loan them to me at the Richmond Symposium. I am going to include them after I return from Symposium.
http://i118.photobucket.com/albums/o83/gbseto/624fd927.jpg
When I posted the pictures, a keen turner noticed the flute on the Mastercut gouges was not symmetrical and asked whether the mold got deformed when I remove the gouge. So I did another casting. It confirmed that it is slightly lopsided. I didn’t buy this gouge brand new. I bought it from a member who moved to a retirement community. I don’t know whether he bought it as seconds or not. I had the gouge for several years; I never noticed any irregularity in its flute until in the cast. This proves my point that casting the molds helps us to see the difference better.
Please share your experience, Gary needs more inputs.
http://i118.photobucket.com/albums/o83/gbseto/b688d4af.jpg
http://i118.photobucket.com/albums/o83/gbseto/5aab1c59.jpg
I have quite a few bowl gouges before I discovered Thompson Tools. Since they all grind at an angle, it is difficult to distinguish the difference in flute shape. I made some wax mold of each gouge and scanned them with a flat bed scanner. I was surprised they also get the 3-D effect in pictures. From the pictures, we can see the difference in flute shape are obvious.
http://i118.photobucket.com/albums/o83/gbseto/ae7dfc00.jpg
Gary Guenther (GaryG in MD) has approached me and suggested he would write an article summing up the collective wisdom from posts regarding the effects on flute profiles. We hope this will generate a lot of subjective comments so we can all benefit from the findings.
Gary has two PSI Benjamin’s Best LX230 5/8” bowl gouges; he is going to loan them to me at the Richmond Symposium. I am going to include them after I return from Symposium.
http://i118.photobucket.com/albums/o83/gbseto/624fd927.jpg
When I posted the pictures, a keen turner noticed the flute on the Mastercut gouges was not symmetrical and asked whether the mold got deformed when I remove the gouge. So I did another casting. It confirmed that it is slightly lopsided. I didn’t buy this gouge brand new. I bought it from a member who moved to a retirement community. I don’t know whether he bought it as seconds or not. I had the gouge for several years; I never noticed any irregularity in its flute until in the cast. This proves my point that casting the molds helps us to see the difference better.
Please share your experience, Gary needs more inputs.