need advice before I ruin a bowl gouge

[Mark Pruitt]

I have a new Vari-Grind and used it for the first time last night. I've watched the video clip on the Oneway site several times to acquaint myself with the jig. I even took notes. For some reason, I cannot seem to get the grind I'm looking for. See attached pics--you can see how the cutting edge is running a concave profile where it should be straight.:(

I need some advice before I proceed further, as this is a Sorby bowl gouge--not something cheap. All help is greatly appreciated!

Mark

edit: When this first happened last night, I decided that I had not removed enough of the "top" portion of the flute edges. I returned the gouge to the platform and ground some more off, essentially "flattening" the edge that is concave in the photos. I then returned the gouge to the Vari-Grind, set the distance the same as before, and wound up with the same problem. The photos show the profile as it is presently.

[Travis Stinson]

Mark, how far out do you have the pivot point set? From the looks of the high wings, it appears to be set too far in. How about an overhead shot of the gouge?

[Jim Becker]

I agree with Travis...the angle of the jig needs to be pretty upright to get the correct exposure on the cheeks of the gouge.

One other thing...some flute designs just don't work with a side grind. (I have a 3/8" Crown that has this problem) But my 1/2" Sorby works great with my Ellsworth grinding jig and gets me a grind "almost" similar to my two Ellsworth gouges.

[Travis Stinson]

You want a slight convex shape instead of a straight grind. If the last pic is after you ground the wings more, spend a little more time on the nose to remove the hook, and roll it into the side profile.

[Mark Pruitt]

Travis, the guy in the video says to use the 5th notch from the top--at least that's how I understood him. I'm attaching an overhead shot, an "upside down" shot FWIW, and a pic of the Vari-Grind as it was set during grinding.
Mark

[Bernie Weishapl]

I agree with Travis. I would like to see a picture from the top. It looks like your nose is to pointy and needs some work on it.

[Lee DeRaud]

Looks like the VariGrind is set "correctly"...as in "pretty close to how mine is set". :p

But I agree with Travis that the pivot bar is set too close in. That bevel on the nose looks too shallow, should be more upright (close to perpendicular to the shaft of the tool): moving the pivot bar out will do that.

Key to this whole operation is that the nose angle is controlled (mostly) by the pivot bar, the side sweep is controlled (mostly) by the VariGrind arm angle. They don't make that as clear in the video as they should, IMHO.

[Mark Pruitt]

OK, grinding more of the nose and reducing the "pointy-ness" sounds easy enough. About the need for the jig to be more "upright," is the setting in the attached pic more like what will work, or do I need to go higher? (This is one notch from the highest.)
Mark

[Travis Stinson]

Mark, I was referring to the sliding arm under the grinder, that the VariGrind sits in.;)

[Andy Hoyt]

Mark - I have my jig set in that "all the way upright position" just as you show in this latest pic. But we have to remember the rest of the variables that come into play that can force further adjustments.

Those are: How much tool is set beyond the end of the jig and the distance between the wheel and the seat of the wolverine.

I've found that all three need to be finely tuned in concert with one another to get the edge that you want. And your preferred edge will likely differ from mine, and Travis' and Lee's and Bernie's.......

All this takes time and experimentation.

[Lee DeRaud]

And your preferred edge will likely differ from mine, and Travis' and Lee's and Bernie's.......In my case, "preferred" is defined as "what I end up with". :eek:

[Mark Pruitt]

I retained the angle setting for the Varigrind, backed the pivot arm out and reground.

THANKS GUYS!!! I could have chewed up an expensive tool trying to learn this w/o your help. I sure appreciate it. You made my day.:)

Mark

[Andy Hoyt]

That's cool Mark. Now to complete the circle for the troops....

How much tool did you leave beyond the Varigrind?

And which setting was retained on the Varigrind?

What was the distance from the seat in the Wolverine to the closest point on the wheel? (which is not the point that the gouge will hit)

Those answers should allow anyone to achieve what looks like a very good Irish Grind - side grind - swept back grind - psuedo Elssworth Grind - et all ad nauseum other names - for this grind.

Well done.

[Mark Pruitt]

That's cool Mark. Now to complete the circle for the troops....

How much tool did you leave beyond the Varigrind?

And which setting was retained on the Varigrind?

What was the distance from the seat in the Wolverine to the closest point on the wheel? (which is not the point that the gouge will hit)

Those answers should allow anyone to achieve what looks like a very good Irish Grind - side grind - swept back grind - psuedo Elssworth Grind - et all ad nauseum other names - for this grind.

Well done.

Andy,

I used 1-3/4" as the distance from the Varigrind to the point. (Before doing anything else, I chucked a forstner into my DP and drilled a hole for indexing.) The Varigrind was set at the 5th notch from the top, as in the first pic of it that I posted. Alas, I cannot tell you what was the distance from the pivot seat to the wheel. I didn't measure it.:( :o

That was a 1/4" bowl gouge. I did it first b/c if I was going to screw up a gouge I'd rather it be that one than the more expensive 1/2". Since then, I have reground my 1/2" as well, and the results are a bit different. The profile is convex like what Travis was suggesting, which seems like a very workable thing. It was the concave profile on the 1/4" that was making me crazy.

So, I'm now seeing what you're saying about everything working in concert. Apparently, the same settings will produce a different grind on a different size gouge. This Wolverine system is cool.:)

Thanks again guys.

Mark

[W.C. Turner]

Mark,

One thing no one has mentioned. You need to know the shape you are trying to achieve before you begin grinding. If you have a photo of the grind you want, keep it close by to compare to, while grinding. Remember, the jigs just control the angles, and, they won't guarantee the final shape. You are in control of that.

[Mark Pruitt]

Thanks W.C., I think I hear what you're saying--i.e. that if I didn't want a convex profile, I could have ground more of the area halfway between the tip and the side of the flute. What I did with the 1/2" gouge was to take off the corners at the top, then simply grind it until I got a consistent edge. At that point, I had my edge and it happened to be a convex profile, and to be honest I was tired of grinding.:p :rolleyes: The more I think about it, the more useful the convex profile seems. Obviously I'm a rank newbie with all of this so when I get a few more bowls to my name maybe if I'm lucky I'll have learned a few things.

I sure appreciate all of you guys taking the time to help me yesterday. Now I'm gonna see what kind of trouble I can get into today.:eek: :D

Mark

[W.C. Turner]

The AAW has a good video on sharpening. In it, John Jordan shows how to do exactly what you are trying to accomplish.

[Kenny Heermann]

Hello and thanks for a very informative thread. Could you post a pic of the tool in the jig at the grinder? I still have trouble getting the right grind.

[Mark Pruitt]

Kenny, here is where you can download instructional videos for the Wolverine jig and accessories.
http://www.oneway.on.ca/multi-media/wolverine_videos.htm

[Mark Pruitt]

I put both gouges to use last night and turned a small bowl from maple. I ran out of time before I could complete it (yeah I know picture police no pics it didn't happen), but all I have left is to turn the tenon off. This piece of maple has a defect and I kept waiting for it to explode, but it never did. I had a severe catch at one point and realized I had to use shear scraping or simply give up and toss it.

The 1/2" gouge with the convex profile worked beautifully, beyond my expectations. I was truly amazed at its cutting capabilities. The 1/4" gouge with the straight profile was a disappointment. I could hardly cut with it at all. I'm going to work with it some more and I may be returning to the grinder with it to form the convex profile I made with my 1/2" gouge.

Mark