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Bench grinder heat issues

memory

memory

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How hot should a motor get on a bench grinder? Just recently got a Dewalt DW756 6" grinder and just after a few minutes of using it, it will get so hot I can't hold my hand on it for very long at all. Only been using it to sharpen drill bits, no hard pressure. Have an older duracraft bench grinder that also gets pretty warm but quite as bad as the dewalt. Is it normal for a bench grinder to get really hot?
 
ammoaddict

ammoaddict

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I would say not. I have a 10 year old craftsman I use to sharpen lawn mower blades. I have it mounted to a board and carry it outside and clamp it to a table. I carry it back inside when finished and I have never felt it being hot. I wrap the cord around the motor so I would probably notice real quick if it was hot.

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memory

memory

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Well I returned the bench grinder and exchanged it for another one of the same model. The new one is doing the same thing. Let it run before bolting it down and doing any grinding and it still gets extremely hot to the touch. Got thinking maybe the power source is the problem. Also have an oregon chainsaw chain grinder and it gets fairly warm as well and is on the same power source. Will try different power source and see what happens.

Not having good luck with this. Decided to keep the 2nd one and bolted it down. This one has a lot more vibration than the 1st. Looks like one of the wheels doesn't spin true, has a wobble to it. I tried a different power source and it still gets hot.
 
CaseyCreek

CaseyCreek

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Oct 31, 2014
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I don't know 1/10 as much about grinders as some of the others on this site, but it seems to me that the armature bearings are not doing their job. I have seen that before on lots of equipment, including my Harbor Freight grinder. The bearings are usually standard and can be ordered cheaply from lots of places. Pretty much all you do is take off the old bearings and put on the new. BTW, a bearing can be garbage and you won't be able to tell by spinning it in your hand.

Other people are having issues with your model of grinder. https://www.dewalt.com/products/power-tools/grinders/bench-grinders/6-150mm-bench-grinder/dw756

You can get new OEM bearings at https://www.toolservicenet.com, but they may be the same not-great bearings which you have now. I have had good luck with just disassembling the grinder/fan motor/shop vac and pulling the old bearing to get the numbers off of the side. Good luck. Let us know what you find.
 
Big_Eddy

Big_Eddy

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Sep 13, 2016
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I ran my 8” bench grinder for most of an hour grinding yesterday, and I could easily keep my hand on the top of it when done. It was warm, but it was no where near hot.
I was working it pretty hard most of the time shaping an axe head mandrel from a piece of bar stock.


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