Why a variable speed grinder?

[Rick Cicciarelli]

I know folks recommend going with a variable speed grinder. I am just curious when you would use the different speeds?

[bob svoboda]

My impression is that some folks get along fine with a high speed grinder, while some stick to slow speed and others like to have the option of either speed (or something in between). Personally I like the slow speed-doesn't remove material as fast, so less waste of expensive steel for me.

[Rick Cicciarelli]

Is there an actual task that requires one speed over the other or does it just have an affect on how fast one can put a new edge on a tool?

[Ryan Baker]

There's really no point to buying a VS grinder. I have one and never change the speed. The idea would be to have a slow speed grinder for sharpening, but be able to turn the speed back up if you want to do some shaping and hog material off faster. Of course, if you have fine grit sharpening wheels mounted, you won't be using them for heavy stock removal anyway. A two-speed (high/low) grinder would do just as well. Of course, a single speed grinder will also do just as well. If VS comes on the grinder you choose, so much the better. But I would suggest not putting VS on your desired features list, and don't pay extra for it.

[Greg Just]

I have been told that a VS grinder is not really necessary but the slower speed just grinds away at a slower rate for those not real good at sharpening a tool.

[Neal Addy]

Do NOT get the variable speed Delta (6" model) if you ever plan to use a Wolverine. The jig doesn't fit under the wheels.

[Rich Aldrich]

The grinders I found at slow speed (1800 - 2000 RPM range) that fit my budget were variable speed. I ended up with a Porter Cable from Lowes for around $130.

[Jim Underwood]

Do NOT get the variable speed Delta (6" model) if you ever plan to use a Wolverine. The jig doesn't fit under the wheels.

Really? Even if you shim up the grinder?

I have a high speed Delta and it does just fine with the Wolverine jig.

[bob svoboda]

I have been told that a VS grinder is not really necessary but the slower speed just grinds away at a slower rate for those not real good at sharpening a tool.

I use a slow speed grinder exclusively and my tools are razor sharp. I consider myself pretty good at sharpening. I do it this way for the reason Mr Geiger stated.

[Don Geiger]

Dear fellow woodturners:

I think the introduction of a variable speed grinder was a wonderful marketing ploy on behalf of the manufacturer. Most poeple either don't know what speed they need or think that someday they might need a different speed, so why get locked in to a single speed when a variable is available?

As a woodturner and instructor, I prefer a recommend using slow speed (1800 RPM) grinders or if you have a variable speed- leave it at its lowest setting. My reasons are:
1) at low speeds you will remove 1/2 as much metal from your tools doing the same task
2) if you make a mistake or have an accident, it will be 1/2 as bad

The motivation for using a slow speed grinder should not be to protect tools from losing temper. A majority of the tools we use in woodturning today are made of materials that will not loose their temper with the methods we use to sharpen them (example: HSS= 1100 deg. F).

I just wish Delta had not discontinued the Model 23-725 slow speed grinder and replaced it with the variable speed. The Model 23-725 was probabaly one of best slow speed grinders on the market. The variable speed model is OK but it does not compare to the 23-725.

Sincerely,
Don Geiger

[Mike Peace]

I started with a 6" Delta VS and sharpened at the lowest speed. Then the electronics for the VS fried (not the switch) and it wasn't cost effective to get fixed. Got the WC 8" slow speed and am a happy camper.

[Fred Perreault]

I have several bench grinders, 6"-8", with assorted wheels and other accessories. I use a high speed grinder for removing quantities of material, going from the coarser to finer wheels as necessary. I use the slower speeds for precise work, or mostly sharpening. I use the 10"x2" water cooled 70 RPM very fine wheel to sharpen my chisels and hand plane knives. I try to keep them balanced and round, which takes time but provides better results.
I do some welding, so I also have a selection of hand held grinders, which can remove lots of material, and be mean some times. jeeeez..... I love tools.... in fact you need them so that you can make a rack to hold them all !

[Jason Roehl]

I can't imagine trying to sharpen a lawnmower blade on low speed, and sharpening my turning tools on my single, high-speed grinder is a touchy proposition. I usually just turn it on with the tool already touching the wheel and vary the pressure to keep the wheel from building up a lot of speed. I could easily see having a VS grinder as a useful tool.