Grinder speed for sharpening turning tools?

[Wade Lippman]

I had always heard that the slower the better; 1725 at most.

But the instructions for the Wolverine sharpening jig say that is too slow; they recommend 3450 on an 8" wheel. Wolverine must know what they are talking about, but could everything I have ever heard be wrong?

[Ken Fitzgerald]

Wade,

They are both right....

There is a line of thought....for folks just starting out grinding turning tools....slower is better.....reason is you have to learn to grind and that takes time and steel.....slower rpm on a given grit wheel means less steel ground in a given amount of time for a given pressure.

If you are experienced I suspect you could do just as well with a faster RPM wheel.

I started out with a Woodcraft 8" slow speed grinder that comes with the white wheels. Probably a good thing I started with cheap HF tools too! Grinding is as much a learned talent as turning. Now I just recently sharpened my new Glaser (sp?) skews free hand. I'd have ruined them two years ago.

[Barry Elder]

What I listen to are the people who make the tools. The people who make the jigs don't know what kind of steel you are working on. From what I can gather, high speed is great for grinding, but low speed is better for maintaining the bevel.

[Gordon Seto]

The people who make the jigs don't know what kind of steel you are working on.

I hope Oneway do. They also have a line of Mastercut turning tools. We all use wheels that are designed for HSS tools.

http://www.oneway.ca/sharpening/wheels.htm

They have different wheels for slow and high speed grinder use.

I believe smoothness of grinder is more important than the speed difference. If the wheel is bouncing, slow speed won't help. Don't overlook light pressure, dress and true the wheel often.

[robert hainstock]

The 3600 rpm will heat the steel faster because of the increased friction. I have both speeds in my shop, and don't have any particular preferance
Bob

[Roger Bell]

I have both speeds. A cheaper Chinese 1725 rpm and an exceptionally nice, 75-80# vintage Walker Turner in 3450 rpm.

Either machine will get the job done, but I much prefer the heavy, smooth running Walker Turner with the fast speed to the Chinese one with the slow speed. I have very high quality wheels on the Walker Turner....a factor more important to me than rpm speed.

I would agree that a slower speed is better for learning to grind.

[Hilel Salomon]

Thanks for the post and the replies. I've been using slow speed for two years and didn't think to ask, even though I've often thought that a higher speed would produce smoother results.
Hilel.

[Dennis Peacock]

I use a slow speed grinder and if I want a finer cutting edge then I use my Tormek. A slow speed grinder with nice A/O wheels on it and balanced will be a very nice way to treat your tools.

[Jim Becker]

My grinder is "high speed" and I get great results using a light touch. The slower speed machines are more "forgiving" while you are learning to sharpen, but not required.

[Jon Crowley]

Could you simply use an external router speed control on a regular grinder to slow down the speed?

[Jim Becker]

Could you simply use an external router speed control on a regular grinder to slow down the speed?

No. You'll destroy the motor. Rheostats cannot be used on induction motors; only "universal" motors that have brushes, such as a non-soft-start router.