High Speed vs Low Speed Sharpening

[Christopher Knight]

I have talked to people who think the high speed grinders are the only way to sharpen tools, and I have spoken to people who think slow speed grinders are the only way to go. Which is really the best? Pros and Cons of each.

This would be my first purchase of a sharpening system. Using my friends Tormek now but he wants it back in a couple of weeks and I need to get my own. I love the Tormek but it is a little expensive. Just looking for some suggestions on what I need to get from people with more experience than I have.

[Jim Ketron]

I use a high speed grinder thats what I already had so thats what I went with.
It is much easier to blue the steel, but if you take light cuts with the grinder it will not happen and realy thats all you need to do is take light cut to sharpen one. (that is if you have the shape you need already)
But I only use HSS for my chisels it will blue reg steel easy.

[Harry Pye]

Oneway recommends a high speed grinder. I figure they probably know more about tools and steel than I will ever know so I go along with what they say. With that said, I just got a 1725 rpm grinder from Woodcraft. I consider that slow speed. My older grinder runs at 3450 rpm and that is what Oneway calls high speed. I'm sure the Tormak is a wonderful tool but I wouldn't consider paying that much money for one.

[Earl Eyre]

I use an inexpensive high speed with a good white wheel and it works just fine. As others have said, the key is very light cuts. At first I used way too much pressure and never got the shape or sharpness I wanted. Now I use all shop made jigs, a light touch, and it works great.

Earl

[Charlie Plesums]

I have a Tormek, and it works very well, but seems to be supporting the entire country of Sweeden. If I were starting over again, I would get a "slow speed" (as in 1700 rpm) grinder. I believe the jig most people recommend with that type of grinder is a wolverine jig system.

[Jim Becker]

It's less of an issue with HSS and other modern metal formulations. For folks new to sharpening, lower-speed grinders can be more "forgiving". Both of my grinders are high speed, but if I were buying today, I'd probably opt for a 1725 rpm unit. More importanly, balancing the wheels is where you can get a lot of benefit...I'm adding the OneWay wheel balancing system to mine as soon as I get around to replacing my wheels which is real soon now...

[Christopher Knight]

Thanks for the input. Now for the big question. Where would be a good place to purchase a grinder? Woodcraft? or online?

[Harry Pye]

Thanks for the input. Now for the big question. Where would be a good place to purchase a grinder? Woodcraft? or online?

Woodcraft is good. They sell and eight inch grinder with two white wheels. Can't remember the grits but one is coarse and the other fine. Normal price is roughly $100 but they put it on sale periodically for less.

[Charlie Plesums]

... Where would be a good place to purchase a grinder? Woodcraft? or online?

If we like having a Woodcraft available to browse or for last minute purchases, we need to support them. If the price is close (often but not always), I buy from Woodcraft. If they don't have it, or it is an item where they aren't competitive, I buy on-line.

Although I belong to the Tormek religion, I have been keeping notes in case I ever changed. Based on lots of discussions over a long period (but not based on personal experience), you should look for a 1700 rpm grinder, avoid the dark silicone carbide wheels, look for the white or pink aluminum oxide wheels, nominally 60-100 grit.

The high speed steel that is common in turning tools should be fine on a higher speed grinder. The carbon steel that was common in earlier tools (chisels, planes, premium kitchen knives) is basically destroyed by heat, so is an argument for the wet grinding like Tormek.

Charlie

[Carole Valentine]

Get the Woodcraft slow speed grinder. The have it on sale often for $75 and it comes with two white wheeels - 80 and 120. After truing the wheels that grinder is the only power tool in my shop that will pass the nickel test other than my Unisaw! LOL I really can't see any sense in paying $200 or more for a grinder for turning tools. I suspect that the reason Oneway says high speed is because that is what most people already have, and if they thought they had to go out and buy a slow speed grinder, they may not buy the WOlverine system! :D

[Don Baer]

The blue borg carries this one.

http://images.lowes.com/product/069554/069554004513.jpg?wid=158&cvt=jpeg

Comes with a white fine wheel and a grey fine wheel. diamond dressing tool and has variable spped from 1725-3450 RPM. so it can be low speed or high speed. Seems loike a pretty decent machine.

[Charlie Plesums]

Almost a hijack of the thread - sorry....

How important is a 6 inch vs. 8 inch wheel? How about the width of the wheel? Tormek is 2 inches wide, but quickly becomes uneven, so needs to be dressed any time you are going to use the width "all at once." The Woodcraft grinder is 1 inch wide. Some of the cheaper grinders are only 3/4 inch or so.

[Jim Becker]

Charlie, I prefer the 8" wheels as they develop a shallower hollow grind, at least until you wear the wheels down substantially. 8" wheels are also generally 1" wide. 6" wheels are most often 3/4" wide. 'No experience with Tormek...

[Don Baer]

The thing people forget about the speed is that it's the surface speed (Inches/minute) rather then the RPM that maters. An 8" wheel spinning at 1750 RPM will have a surface speed 33% higher then a 6" .

In terms of width, It depends on what you are trying to sharpen. If it a flat surface then wider is better.