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View Full Version : 8" bench grinder died: Opinions on the DeWalt DW758



Roger Feeley
08-29-2019, 11:53 AM
My old Craftsman bench grinder died after many years. I bought at a surplus store for $25 about 35 years ago so I suppose it was time. I took the wheels off and it still won't start unless I manually spin the arbor. There's this grinding noise inside.

I want to stick with the 5/8" arbor. Someone gave me the Oneway wheel balancing system years ago and it really works.
I will also trash the tool rests. Someone (different someone) gave me a couple of Veritas tool rests.

So I'm thinking about the dewalt.

Thoughts?

Mike Henderson
08-29-2019, 12:04 PM
If it will run when you spin it up, you can almost surely repair the motor. I'd replace the bearing and put a new starting capacitor in the motor. Neither is that expensive so you aren't taking a big risk.

About the only thing that can happen to an electric motor that really destroys them is if the stator coils burn. Even that can be fixed but it's usually less expensive to buy a new motor.

Mike

Jeff Monson
08-29-2019, 12:37 PM
I've had the DW758 in my auto shop business for at least 4 years. It gets used and abused daily and still works like a champ. It has decent power for the price, I'd give it a 2 thumbs up. I'm sure its on its 5th wire brush and 4th grinding stone.

Dave Cav
08-29-2019, 1:21 PM
I'm with Mike; take the Craftsman apart, and if the windings are still good, replace the bearings and cap(s) and it should be good to go. (But if it has sleeve bearings it might not be worth the effort.)

I don't have any experience with the DW grinder you referenced but I see it's 3600 rpm, which I find too fast for sharpening. A few years ago when I needed a new grinder for sharpening chisels I got the Jet 1800 rpm 8" grinder and it's worked great. I have pink and blue wheels on it but eventually one or both of them will be replaced with CBN....after about a dozen other things get done.

Bill Dufour
08-29-2019, 1:33 PM
Many grinders do not have a starting switch to go bad. If it makes noise probably it is a bad bearing. The cap may be a flat pack inside the base.
Bill D

Roger Feeley
08-29-2019, 1:54 PM
thanks to all. I took both side housings off and the bearings seem fine. But there is no way I can rotate the rotor without getting the grinding noise.

Roger Feeley
08-31-2019, 11:46 AM
I unpacked the dewalt this morning. Runs smooth.
some reviews on amazon complained of vibration so I tested on the shop floor and stood at a distance. I was ready to do a long investigation of runout, etc. no need.

Tom Trees
08-31-2019, 11:51 AM
thanks to all. I took both side housings off and the bearings seem fine. But there is no way I can rotate the rotor without getting the grinding noise.

Is that a problem with the centrifugal switch then?

Tom

Roger Feeley
08-31-2019, 3:10 PM
I don’t know and I really needed to have a grinder. I just didn’t want to invest any more time in it. The old grinder is torn apart for recycling. I saved the shaft and the switch. I didn’t see an easy way to get the bearings out but I don’t have much call for bearings anyway.

case closed. The new grinder is all settled in on its stand.