Turning Archive 2004
>I have just set up a grinding system with a Wolverine Grinding jig and wanted to reprofile one of my bowl gouges to something near the "Ellsworth grind" to see how I would like it. Only having the instructions that came with the Wolverine and only pictures of similar profiles from the WC Grind Library, I wondered how I could change the profile without wrecking a good tool and I also wanted to minimize steel loss on the tool.
The solution I came up with was to try a test grind using a piece of steel rod. I happened to have a piece of 5/8" rod. I was going to reprofile a 3/8" bowl gouge, but I figured I could practice on the 5/8" rod and then go to the bowl gouge. I set up the Wolverine to put the standard bowl gouge profile on the end of the rod - just using the "V" arm and rolling the rod to duplicate the grind angle on the bowl gouge. I had to guess at the starting distance of the "V" arm from the wheel, but after I had a 1/8" bevel ground, I set the angle on a sliding bevel and then checked it against the angle on the bowl gouge. I had to adjust the arm once and then got quite close to the bowl gouge grind. I wanted to do this so I could start the reprofile from the same profile that I would be starting from on the gouge.
Then I set up the Vari-grind jig according to the directions that came with it. I set the rod to extend 1 3/4" out of the jig and then I approximated the distance of the "V" to the wheel to get the proper nose angle. I ground about an 1/8" bevel, set the sliding bevel to that angle and checked it using a protractor. I found I wasn't grinding the nose to a steep enough angle and reset the "V" arm. I had to adjust a few times to get the correct angle. Then I started grinding the side profile. When I got the profile I wanted, everything was set correctly to replace the steel rod with the gouge I wanted to reprofile. (If the "V" arm is set for the profile you want and you set the same distance when setting the tool in the Vari-grind jig, you duplicate the grind that you made on the rod.)
I replaced the steel rod with the gouge and started grinding. I ground slowly and paid attention to not overgrinding the nose which is very easy to do. The sides needed quite a bit of grinding to get the profile I wanted, but I was able to duplicate the profile I had created on the steel rod.
I haven't had a chance to try the new profile on a bowl, but I had a waste block from a previous bowl still on a faceplate and took a few swipes at it. Very nice cutting profile! I like it!