wolverine recommends 3450 over 1725 RPM?

[Paul Coffin]

Hi,
I am looking into the Wolverine sharpening jig. I have read several posts by people using slow 1725 rpm 8 inch griders with the Wolverine jigs. The lower RPM aids in not burning the tool. But I just was at the Oneway web site reading the Wolverine instructions and they recommend the standard 3450 RPM grinder. They state that you obtain the proper surface velocity with the faster grinder, sharpening quicker and therefore not building up excessive heat.

I already have a couple 3450 rpm grinders, is the slower 1725 grinder really worth it? Oneway does not seem to think so, what do you think?

-Paul

[Ken Fitzgerald]

Paul,

I use the Woodcraft Slowspeed grinder in conjunction with the Wolverine. It works well for me. It was recommended to me because I was unfamiliar with grinding/sharpening tools. If you are familiar and have experience, the 3450 rpm might work well. If not, the theory is you will grind off less of the expensive turning tool while you are learning to sharpen.

[Gordon Seto]

I think the slow speed is over emphasized. How steady and smooth the grinder runs is far more important. If the grinder is vibrating, the slow speed is still too fast. Keep the wheel true and clean, light touch with control, appropriate wheel would avoid the overheating problem.

[Leo Van Der Loo]

faster for professional turners, time= money.
best speed depends on the kind of wheel used
Faster = more vibration often, like a car at 50 MPH or at 100 MPH

[ROY DICK]

Paul,
I have the slower speed grinder and have never had a problem with heat build up. I just use a light touch on the tool to the grinder and it works for me. Keep the wheel dressed as mentioned.

Roy

[robert hainstock]

I see no mention of wheel size in these discussions, so will throw this into the mix. surface travel per in in a six in wheel at a nominal 3600 RPM is not al that much faster than surface travel per in in an 8in whell doing 1725 RPM. If you aspire to be, or are a pro turner, go with an 8in 3600RPM machine. I'm way past being in a hurry, and the 8in slow speed works fine for me, and I use the two 6in hi speed machines for buffing, (steel), wire brushing rust, and fast metal grinding on rough stock.:)
Bob

[Aaron Wingert]

Or do like I did and get a variable speed 8" grinder, that way you can choose what speed works best for your everyday sharpening. My grinder stays at about 1/3 of its speed potential for most sharpening tasks. I will say it helps to slow it down quite a bit if you're forming a new scraper shape, new gouge profile or something else that requires removal of a little more steel than usual sharpening.

If you're new to sharpening on the grinder it would probably be best to opt for a slow speed grinder since getting the right profile might take you a little longer. Once you're proficient and faster I doubt it'll make much difference.

[Alan Tolchinsky]

It seems that the low speed with the right compound wheels removes metal very fast. At least it's fast enough for me. And with the Wolverine jig you are removing very little metal when you set the tool up correctly.

[Walt Caza]

Hi Paul,
I just went through the same process.
Ya, I read that Oneway recommends 3450rpm.
Being a complete rookie, I went against it and chose a 1725rpm grinder.

I suspect their program and advice are aimed at serious turners?
I'm just a fumbling hobby dabbler trying not to lose any teeth to a missile.

I also bought Oneway's 80 and 120grit wheels.
I'm happy with my set-up and making good edges.

Please note that Oneway offers specific wheels for each grinder type.
Slow wheels for slow grinders, and fast for fast.
The letter which denotes the bond hardness varies.
good luck with it,
be well,
Walt

[jason lambert]

Every one I know uses a slow speed, in fact I just got a tormec even slower but more accurate, although they have a new stone which is faster for hss. If you are constinally resharping the same guage and knocking stuff out and tuching up i can see the fast speed but if you are not doing it every day withthe same tool use a slow speed, that i my opion.

[Bob Hallowell]

There has been alot of threads on this topic- alot use and recommend the low speed if buying new. I had an old 3400 rmp 8" rockwell and couldn't see any reason buying a new grinder. It works great I learned on it and still use it 4 years later with no problems. as long as it does wobble I don't think the speed matters- Plus the whole topic of heating the steel is a mute point as most of us use hss steel which doesn't lose it temper.

Bob

[Ryan Baker]

I think the heat issues are the result of too fine a wheel grit, allowing build-up in the wheel, using too much pressure, or just overgrinding. The speed of the grinder has little to do with it. You can do the job quite well with either using proper technique. The slower speed grinders are a little easier to use, especially when learning, because they leave a little more room for error, i.e. you don't grind yourself into trouble quite as fast.

If you already have a good 3400 grinder, or you can get a good deal on one, there is no reason not to use that. If you are buying new, a slow-speed grinder or a variable speed grinder add some options. Getting 8" over 6" is a much more important option.