What should I look for in a used bench grinder?

[Bob Stroupe]

I've been using sand paper and a sheet of plate glass for all of my sharpening needs, and I've decided I would like to get a bench grinder for the heavy stuff.
I see bench grinders on craigs list going for $20-$50 all the time. For the most part they all seem to be 6" normal speed with a grey stone and a wire wheel.
I'm wondering what should I look for? Is there a particular brand to hunt down or stay away from? Bench grinders are basically electric motors, aside from power speed and wheel size, is one that much different from another? Would a cheaper grinder with the proper stone be a better purchase than a high dollar grinder without it?
Thanks

[David Weaver]

Get one with a two piece rest that you can adjust both the angle and the distance from the wheel independently. There is a ryobi grinder that was made for a while that had decent large flat rests of that type with hand screws.

Pretty much any grinder with decent bearings and a shaft that's still straight will be fine. If you have to start buying rests, though, or making your own, you'll be adding a lot of time and hassle that's not necessary.

No matter what you get, you'll need to buy a diamond or carbide wheel dresser (I think LV has the diamond one cheap), and you'll likely have to buy new wheels unless you don't mind out of balance wheels that cause the grinder to get the shakes and skip as you grind with it (you can still use a grinder like that for hollow grinding if you clamp or screw it down).

If you find an old one with good rests, coarse wheels and good balance, consider yourself lucky, but it's good to shoot for that.

[Roy Griggs]

I have been using a low speed, 1750 rpm, bench grinder from Woodcraft @ approx $100 for 5 yrs. and have been very happy with it. This is their cheapo but mine's been a good machine. I'm not sure what kind of rest it came with as I never mounted them; I built my own. The white wheels that this grinder come with are good enough to use till they need replacing from wear. Although this is slower than a 3450 rpm grinder with gray wheels, I worry less about burning small blades.

[john brenton]

Lowe's has a 6" porter cable for $70 right now. I know that's not an insane stellar deal, but I finally just went ahead and sprang for one and I really like it. It runs smooth, variable speed, two part tool rest (they sit relatively square), nice light, water tray. etc.

It's much better than the craftsman or skil ones out there.

[QUOTE=Bob Stroupe;1601572]I've been using sand paper and a sheet of plate glass for all of my sharpening needs, and I've decided I would like to get a bench grinder for the heavy stuff.

[Rick Erickson]

Make sure it is well balanced. Have the seller run it for you. Get a coarse wheel (less friction thus less heat). David already mentioned the 2-piece rest. Wolverine makes a great one. It is a large chunck of steel and acts as a great heat-sink. IMO 8" is better than 6" because of the hollow-grind you get with these. For planes it's not too big a deal but for mortise chisels you want as much steel behind the cutting edge as possible and the 6" grind takes a lot of that away. If you aren't doing heaving chopping tools it probably isn't as big a deal. I bought a cheap Woodcraft grinder and am happy with it (but it did take some work to balance it though).

[Bob Stroupe]

Thanks for the advice.