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Can we talk about the Batty 40/40 grind?

G

Greg Muller

Joined
Jun 20, 2020
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Kansas City, MO
I'm curious.
Is it used by many of you? What do you feel it's strengths are? From what I've been told, it just gives you the same angles from different portions of the grind, so less frequent trips to the grinder. Is there more to it?
 
All things being equal 40 degree bevel is a sharper and cuts cleaner than a 60 degree bevel

You can’t hollow a hemispherical bowl using a 40 degree bevel
You can hollow a hemispherical bowl using a 60 degree bevel.

one feature of the 40/40 is that you have close to a 40 degree bevel angle all around.

I use the Ellsworth grind most of the time. The bevel angle changes around the cutting edge.
Nose is 60 degrees holds up well for roughing cuts
sweet spot off the nose is 45 degrees this is almost as sharp as the 40/40 for push cuts
the wing is 30 degrees - used for pull cuts and is sharper than the 40/40

I have a 40/40 that I use sometimes
Also the Michelson grind works really well for finish cut.
 
I don't see a big advantage of 40/40 other than having a cleaner cut if you can still ride the bevel on the shape you need. I don't see having the wings be 40 degrees as a particular advantage. In fact what I'm doing now with my Henry Taylor U shaped gouge that I used to grind at 40/40 is to sweep the wings back further so I start the grind around 45 degrees or more. Or if you grind from the nose out I simply swing the handle further to give me a longer wing. I do a lot of cuts using the wing. I have not measured the actually cutting angle of the wings because I don't have a good way to do that. My favorite gouge is my Thompson V that I grind in a more or less Ellsworth grind with longish wings. The nose angle is 55 degrees which doesn't cut quite as clean but reaches more areas than the 40/40 so is more useful for my style of turning. Doing shallow bowls like Natural edge bowls with a really shallow curve the 40 degree nose is great. As far as needing to sharpen less because the wings are 40 I don't see it happening for me.
 
I prefer the 40/40 for all of my bowl turning on the outside of the bowl, and for going down the inside wall of a bowl. You can not use it through the transition area of the bowl or for going across the bottom of a bowl unless the bowl is very flat, or you are turning a platter. Simply, it cuts cleaner. I did notice, the last time I saw Stuart demo, maybe a year ago, that he holds his tools more level as compared to the dropped handle. This is cutting more with the nose, and rolling the tool on the side rather than the flutes more up and cutting more with the wings. This is the way I have pretty much always turned when turning bowls. The 40/40 grind does take less effort to cut with, especially if you are roughing with it. Me, I do all of my roughing with scrapers, then one or two passes with the 40/40, and I am done. There is a method for doing the 40/40 grind with a jig, and I will see if I can find that link again as this came up on another forum. It involves having a 3 inch protrusion from the Wolverine 1 rather than the more common 2 inches. No clue as to how much actual difference it really makes in how effective this tool is. When turning the inside of the bowl, when I get to the transition, I switch to a 60 or 70 degree nose bevel angle, and I grind away about 2/3 of the heel, rounding it over rather than having 2 straight bevels. I don't use swept back gouges at all any more. No use for them. The only one I can think of would be for shear scraping, and I prefer a scraper with a burnished burr for that.

As for platform sharpening, once the angle is set, it is a very simple process. The trick is learning that what you do when sharpening is exactly what you do when you turn. Anchor the tool on the platform, rub the bevel, and cut. You move with your body, and not your arms. If you only turn once or twice a month, it won't be easy. If you turn a couple of times a week, it is a fairly simple process to learn.

robo hippy
 
My experience matches Robo's pretty closely. I used an Ellsworth grind for everything for a very long time, about a year ago I added a couple new bowl gouges, grinding one 40/40 and another as a "bottom feeder). I find the 40/40 to be much faster in roughing the outside of bowls and hollowing down the inside, more vertical surfaces, It takes a lot of wood very quickly with less wear and tear on me. I can take a much bigger cut with it than I can with my Ellsworth ground tool and get a nice surface when it's sharp. I do have to switch tools to do the curve and bottom, but that seems a minor inconvenience. I haven't developed a strong preference for the dedicated bottom feeder, it's better, but not that much better,
 
Pretty much the same as Robo & Roger. I use the 40/40 on the OD and down the ID walls. I also use a 60 with wings For transitions and a 70 bottom feeder, it depends on the project shape whether I need the 70.

The 40/40 gets used all the time roughing. Sometimes its too aggressive for me for finish cuts and I’ll use the 60. I dont think it changes any sharpening intervals. It hogs wood well.
 
I've watched several. Great info, so I'm going to give it a try, just thought I'd get more insight from folks here to get realistic expectations.
I was seriously considering the Stuart Batty tool holder system that allows switching gouges, but then learned that they require a different taper part to be glued onto each separate gouge. Kinda ruins the deal. And I also learned they aren't being made anymore, so once stock runs out, they're gone.
 
I think SB’s tool holder was a collet? Anyway, I use shp made wood tool handles, but for bowl gouges I wanted to be able to remove the tool for sharpening. I used AL holders from Cindy Drozda’s website. They use 2 set screws to hold the tool in place. Only used the 5/8” size. Appear to work well, no increase in toolvibration. I think they were $20 each.
 
Yeah. It was a collet, and you had to glue the tool into a bolster, which tightened into the collet. I really love the idea of how it worked, especially without needing set screws, but it apparently didn't catch on, and he doesn't make them any more. Current stock only.
 
Yes the batty system looks great till you discover that detail. Serious design flaw. Currently woodworkers emporium still makes the sbt handle but uses the robust collet system which appears freakin awesome. Jimmy Clewes also has a very nice collet system. I have not taken the red pill yet but if/when I do quick release seems like a must have.
Re 40/40, to stay relevant. I like it very much. But my experience is miniscule compared to others.
 
Raif Harik said:
Yes the batty system looks great till you discover that detail. Serious design flaw. Currently woodworkers emporium still makes the sbt handle but uses the robust collet system which appears freakin awesome. Jimmy Clewes also has a very nice collet system. I have not taken the red pill yet but if/when I do quick release seems like a must have.
Re 40/40, to stay relevant. I like it very much. But my experience is miniscule compared to others.
Click to expand...

If you look on the Woodworker's Emporium site , under SB Tools...you will see the SB Taper Lock. I like it better than the collet system, with the exception that you must epoxy the tool steel into the socket. But, you can heat - and remove it when ready to replace the gouge or other tool.
 
Last edited:
Raif Harik said:
Yes the batty system looks great till you discover that detail. Serious design flaw. Currently woodworkers emporium still makes the sbt handle but uses the robust collet system which appears freakin awesome. Jimmy Clewes also has a very nice collet system. I have not taken the red pill yet but if/when I do quick release seems like a must have.
Re 40/40, to stay relevant. I like it very much. But my experience is miniscule compared to others.
Click to expand...
What is the serious design flaw? I have been using about 5 SB handles without any problems for a few years.
 
Well, if there is a design flaw, to me, it would be that Stuart's tools only fit into his handles, and they are not universal for all handles. This is not an uncommon practice in business. Personally, I don't like his long handles, but tools are top quality.

robo hippy
 
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