Author Topic: 40-40 bowl gouge grind with Tormek  (Read 517 times)

Offline Ken S

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40-40 bowl gouge grind with Tormek
« on: November 23, 2020, 05:58:44 pm »
At about 45 minutes on this you tube, Stuart Batty states that the Tormek jig works pretty well doing the 40-40 grind.
I do not believe he means exactly. I am curious to know what settings and technique with the Tormek get close, and what technique might be used to fully match this grind.
Thoughts?

Ken

Here is the link:

https://youtu.be/QMVGankeK0I

Offline RichColvin

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Re: 40-40 bowl gouge grind with Tormek
« Reply #1 on: November 25, 2020, 03:18:18 am »
Ken,

I use these settings for the SVD-186:
  • JS = 2
  • P = 75mm
  • TT-100 Hole setting = A
It is documented here:  http://sharpeninghandbook.info/WW-BowlGouge.html

Kind regards,
Rich
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Rich Colvin
www.SharpeningHandbook.info - a reference guide for sharpening
www.ColvinTools.com

You are born weak & frail, and you die weak & frail.  What you do between those is up to you.

Offline Ken S

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Re: 40-40 bowl gouge grind with Tormek
« Reply #2 on: November 25, 2020, 06:06:12 pm »
Rich,

Outstanding post! I have come to rely on your Sharpening Handbook as my go to knife sharpening reference. You really shine as a turning go to source. It will take me a while to digest all of the information.

In the video spot I referenced, Stuart Batty states that the Tormek and SVD-185/6 come close to freehand sharpening, having two contact points. He states his hand sharpening method uses three points. If the Tormek gets close with two points, what does it take to complete the third point?

According to SB, his 40-40 grind allows taking a more aggressive, deeper cut while still getting a good finish, two worthy objectives. The Tormek really shines with repeatable, well honed sharpening. If possible, I would like to combine qualities of both. Incidentally, SB also mentions that he often uses his 40-40 bowl gouge where others would use a spindle gouge of skew. Interesting possibilities.

Your settings will give us a leg up on this journey.

Ken

Offline Boston_turner

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Re: 40-40 bowl gouge grind with Tormek
« Reply #3 on: November 27, 2020, 05:38:57 pm »
I missed this particular thread and found a different one about using the SVD-185/186 where there wasn't a clear answer about a year ago. After watching a Stu Batty video I decided to try 40/40 on a 1/2" bowl gouge.  I have the SVD-185 and after playing around a bit I found that JS=5, P=65 and hole=B got me 40/40.
It sure takes a lot off from the wings.

Offline Ken S

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Re: 40-40 bowl gouge grind with Tormek
« Reply #4 on: November 28, 2020, 03:29:01 am »
Interesting reply, Boston turner.

I wish I understood the relationship of the gouge jig settings. From the kenjig, I realize more than one combination can produce the same result; however, it does puzzle me that JS5, 65mm and hole B can get the same result as
JS2, 75mm, and hole A.

I am not doubting either setting; I just wish I knew enough to understand things.

Thanks for your replies.

Ken

Offline Boston_turner

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Re: 40-40 bowl gouge grind with Tormek
« Reply #5 on: November 28, 2020, 03:54:24 pm »
I went back and rechecked everything. The bottom line is ignore what I posted.

The 2/75/A works very well. I reground that gouge with those settings. The one I was using was not too far off but not 40/40. I suspect it was only close because I had not paid attention to how dished the stone had become. Also, working with a B hole was harder than an A distance. I'll put that down to trying to do too many things at the same time and glad there are others here to keep things straight.

Perhaps more importantly, the 40/40 grind didn't suddenly make be as good a turner as SB!


Offline Ken S

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Re: 40-40 bowl gouge grind with Tormek
« Reply #6 on: November 28, 2020, 05:32:51 pm »
Boston turner,

How refreshing; an honest turner! SB had the advantage of several years as an indentured servant (more politely termed "apprenticeship") working for his father. To be fair, it sounds like a happy relationship.

The Tormek philosophy, as illustrated in "Touch N Turn", has many good points. It helps both beginners and more advanced turners develop consistency. The flip side of this consistency is that some useful grinds have been left out of the canon. Based on Stuart Batty's videos, the 40-40 grind seems a useful part of a turner's toolbox, and well worth including in the Tormek method. It seems logical to combine the 40-40 grind with some of the recent honing and deburring advances added to Tormek knife sharpening.

I feel the same way about the Alan Lacer skew grind. Why not have the best of both worlds?

Ken