Author Topic: Stu Batty 40/40 grind  (Read 1673 times)

Offline boehme

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Stu Batty 40/40 grind
« on: October 25, 2017, 11:46:46 pm »
I was wondering if anybody has tried replicating the Stuart Batty 40/40 grind using the Tormek.  If anybody has successfully accomplished this what are the jig settings used?

Offline AKMike

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Re: Stu Batty 40/40 grind
« Reply #1 on: November 03, 2017, 07:08:56 am »
I'm sure that you know that you can do that grind freehand using the SVD-110 tool rest and following any of the many videos that are out there, so I guess you're asking about using the SVD-186/185. I've never had a gouge with that particular grind, and I don't have a spare gouge to practice on, so I can't help you too much. However, jig setting 5 with the SVD-186/185 will get you the 40 degree angle from horizontal that you need. The numbers on the jig are units of ten degrees from parallel with the jig axis of rotation. You want 40 degrees from perpendicular or 50 degrees from parallel, so jig setting 5. Then it is just a matter of picking the one of an  infinite number of combinations of protrusion and USB setting that give a 40 degree nose angle that results in the grind that you want. Protrusion 55mm and hole B on the TTS-100 comes close, but results in a nose angle of about 45 degrees, instead of the desired 40.

Not much help, I know, but if you find the right combination, please share.

Mike

Offline Ken S

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Re: Stu Batty 40/40 grind
« Reply #2 on: August 04, 2018, 05:01:12 am »
Good post, Mike. You saved a lot of trial and error with the jig setting.

Setting the bevel angle with the TTS-100 setting tool should just be a matter of using the 65mm slot. Place a piece of masking tape in the 65mm slot with a pencil mark at half depth. Grind the bevel and measure the angle. This should get you closer. Keep guesstimating. Your next guess should be very close.

Ken

Offline SVB

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Re: Stu Batty 40/40 grind
« Reply #3 on: June 26, 2019, 10:12:48 am »
Hi folks - did this ever land as a ‘recipe’?

Thanks

Simon

Offline Ken S

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Re: Stu Batty 40/40 grind
« Reply #4 on: June 26, 2019, 03:50:56 pm »
Welcome to the forum, Simon.

To the best of my knowledge, there is no published Tormek recipe for the Batty 40-40 grind. It and the Alan Lacer grind were unfortunately not included in the Tormek TNT-300 Woodturner's Instruction Box book and DVD. The TNT-300 is generally very done. I consider the DVD the most outstanding video Tormek has ever produced. However, it does have a few deficiencies. Part of the problem may be due to when it was made. I don't know the exact date, however, the Tormek used in it was a SuperGrind. There is nothing wrong with the SuperGrind and SG-250, however, the DVD predates the SB, SJ and diamond wheels as well as more recent jig designs. I suspect the DVD and book also predate the popularity of the Batty and Lacer grinds. Jeff Farris, who was instrumental in the project is an accomplished turner. He is also partial to Sorby turning tools. Neither the Batty nor the Lacer grinds are available through Sorby.

I hope Tormek will produce an updated version of the book and DVD. Until that happens, I suggest following Mike's advice and making controlled test grinds. Mike's jig setting5; protrusion 55; and
hole B will get you close. Assuming you want to get closer, try lengthening or shortening the protrusion by 5mm. My math is not quite awake this morning. I think shortening the projection will produce a slightly higher angle. If a change of 5mm gets you closer, try increasing the variation slightly. By the second variation attempt you should be close enough.

Keep us posted.

Ken

Offline RichColvin

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Re: Stu Batty 40/40 grind
« Reply #5 on: June 27, 2019, 03:11:14 pm »
I think it is doable with the SVD-186.   I don’t use that grind, but I know a 40° nose bevel is doable, and the 40° wing angle is about the grind depth on the side swings. 

I’ve detailed this in my Sharpening Handbook on this page :  https://www.sharpeninghandbook.info/WW-BowlGouge.html.

I really recommend the SVD-186 based approach.  It is very repeatable.

Kind regards,
Rich
---------------------------
Rich Colvin
www.SharpeningHandbook.info

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: Stu Batty 40/40 grind
« Reply #6 on: June 27, 2019, 03:51:44 pm »
Rich,
I agree about the repeatability benefits of the SVD-186. The first skew I worked on was close to a Tormek profile, but not exactly so. I was surprised with the extra amount of grinding necessary. The next sharpening was considerably quicker and easier on both the tool and the sharpener.

Following my Irwin chisel idea, I think we should also have comparable learning turning tools.
Ken

Offline Twisted Trees

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Re: Stu Batty 40/40 grind
« Reply #7 on: June 27, 2019, 05:35:12 pm »
I also agree, I don't use the 40/40 grind but the thing with woodturning is you need to sharpen often so quick repeatable and accurate are the watchwords. plus you really wouldn't know the difference between a 40/40 and a 39.5/42 when in use anyway, so get the basic profile that works both for you and for your jigs, then you won't be tempted to continue with a blunt tool rather than fussing around with jigs!

Those experienced with freehand sharpening may get an almost perfect angle on sharpening but it is only ever almost ;)

Offline Ken S

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Re: Stu Batty 40/40 grind
« Reply #8 on: June 28, 2019, 03:51:56 am »
TT,

Step into your nearby forest and ask one of your local bodgers. I believe they generally prefer 39.3/42.1    :)

Ken

Offline Ken S

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Re: Stu Batty 40/40 grind
« Reply #9 on: June 28, 2019, 03:57:59 am »
On a more serious note, I think uniformity of settings is important to minimize both the amount of metal removed from the tool and the amount of remaining time subtracted from the turner's lifetime. However, we must not lose sight of sharpening being done for centuries under all different freehand conditions by individual workmen. The old craftsmen did some "pretty fair" work.

Ken