6" or 7" wheels for a 3,450 rpm grinder?

[Rich Tesoroni]

Picked up an old Delta grinder without wheels. Seems like there's more 6" than 7" wheels available (looking a bit online and at the Norton web site). Wanted to put it by the lathe.

Would using 6" wheels be better for lathe tools at the higher speed? FWIW, I've got a Woodcraft 8" slow speed on the other side of the garage.

Is either one better to dedicate next to the lathe?

Thanks,
Rich

[robert hainstock]

Most if not all grinding wheels are made of so grangible material. If you go to the seven inch wheel, you may run the danger of centrifigul force blowing up the wheel. If there are wheels specificly marketed for 3600 rpm grinders, they would probably be OK. :eek::eek::)
Bob

[Steve Schlumpf]

Rich - just my opinion but I would use the Woodcraft slow speed grinder for all your turning tools. Turning tools are expensive and once you have the profile that you want - you only need to remove a little bit of metal from then on. A high speed grinder will remove a lot more steel just because of the speed.

Other thing to consider is the hollow grind that you get when sharpening. A 6" wheel will give you a very pronounced hollow grind when compared to an 8" wheel.

I have both a 6" 3450 rpm and a Woodcraft slow speed - I only use the Woodcraft for turning tools!

[Tom Steyer]

1. Park the Woodcraft grinder with some good Aluminum oxide 8" wheels next to your lathe, and don't use it for anything other than tool sharpening.
2. Put the delta on the other side of the shop for your lawn mower blades and general grinding. Don't even look at that grinder with a lathe tool in your hand!

[Mike Golka]

Listen to Robert, Steve, and Tom they are absolutly correct. Slower/ bigger is better.

[michael gallagher]

Slower is better, as the previous posters said.

However, why not turn the high speed grinder into a dedicated buffing station?

[Bernie Weishapl]

I agree that the Woodcraft slow speed for your turning tools and put the other one on the other end of the shop.

[Bob Hallowell]

I have an old rockwell 3450 grinder I was given and it is all I ever used. I have had no problem finding 8" wheels. I see no down side using it as my turning tool grinder. I am able to just touch up tools like anyone else without removing to much metal.

Bob

[Leo Van Der Loo]

I have a 1940-45 era Stanley 7" 3450 rpm 220V DC grinder, has never ben bolted down and just sits there humming, the thing though is that the old machinery and the new low cost ones, made wherever it is cheapest to be made, are nowhere in the same class of engineering or quality build.
My second grinder is a 1 HP 1750 RPM 110V AC 10" grinder, it is a Taiwan made grinder, when I bought it I had the place I bought it take out 3 and have them run before accepting this one, as all of them where walking across the floor, the one I bought was best but not perfect, and I did some more balancing on it when I got it home.
The high speed grinders (3450 RPM) are more likely to vibrate than the slower speed grinders, just the way things work, so taking all things equal, I would use the grinder that runs the smoothest for sharpening my turning tools, and if equal, i'd choose the larger wheel for the better geometry of the bevel, HTH

[keith zimmerman]

I use the 6" wheels on my Delta 3450 rpm grinder. They work just fine on HSS tools. You just have to be very careful with carbon steel tools.