# Angle grinder overheating...



## Duke (Jan 7, 2019)

I have a new 850 watt Ryobi angle grinder that seems to get really hot. After a minute or two's use the front of the grinder is really hot and takes quite a while to cool down.

Running it with no load does not seem to cool it down at all.

As a comparison I have an old 600 watt ryobi angle grinder that has really seen a lot of pretty hard use and it hardly seems to get hot.

How hot does your angle grinder get during use?


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## hermetic (Jan 7, 2019)

by the "front" do you mean the gearbox end or the motor? If it is the gearbox, could be lack of lube, if its the motor, electrical problem, in either case, if it is that new, take it back!


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## Duke (Jan 7, 2019)

Hi!

It is the front end where the gearbox lives.

I will return it when I am in town again..


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## FOMOGO (Jan 7, 2019)

When I get a new cheap grinder, i.e. HF, Ryobi, etc., the first thing I do is tear it down and make sure all the connections are good, brushes are running true, and most importantly change out the sad excuse for grease in the gearbox with some good molly of known origin. They seem to immediately run stronger, quieter, and cooler. When replacing the grease don't overpack the head. Mike


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## Duke (Jan 7, 2019)

FOMOGO said:


> When I get a new cheap grinder, i.e. HF, Ryobi, etc., the first thing I do is tear it down and make sure all the connections are good, brushes are running true, and most importantly change out the sad excuse for grease in the gearbox with some good molly of known origin. They seem to immediately run stronger, quieter, and cooler. When replacing the grease don't overpack the head. Mike



Good Idea - I will return this one tomorrow and then do a teardown on the replacement.....


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## ezduzit (Jan 7, 2019)

Duke said:


> ...do a teardown on the replacement.....



That will almost certainly void any warranty.


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## FOMOGO (Jan 7, 2019)

ezduzit said:


> That will almost certainly void any warranty.



If you are returning it to any major retailer, no one will ever even look at it. Take your receipt, and they will just hand you another one. Not saying this is good or bad, just the way it is in our throw away world. Mike


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## David S (Jan 7, 2019)

FOMOGO said:


> If you are returning it to any major retailer, no one will ever even look at it. Take your receipt, and they will just hand you another one. Not saying this is good or bad, just the way it is in our throw away world. Mike



Yes Mike sad indeed.

Way back when our retailers used to ask customers why they were returning a product and filled out a sheet.  They stuck that to the tool and it was sent back to us, the manufacturer.  Every so often we would gather up these returns and do a tear down to see what went wrong and how we could improve.  The descriptions were usually very helpful.

Then the retailers decided it was too much work to send stuff back, and I don't think customers liked being questioned.  So they stopped and just trashed the tools.  We lost valuable early warning feedback on how to improve.

David


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## RJSakowski (Jan 7, 2019)

A bigger problem is when the retailer just sticks the product back on the shelf.  I bought a power hand planer from a national big box DIY.  When I looked at it, there was wood dust accumulated in the dust port.   I called and arranged to get another, this time in a factory sealed box but it involved a second 50 mile round trip and a couple of hours of my time.


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## Downwindtracker2 (Jan 7, 2019)

The company I use to work for, replaced tools that were broke or lost. For mini grinders we would buy a cheap one on sale and wear it out in short order. The company then replaced them with good made in Germany Walters. The Walters lasted longer but would  also meet that same fate. We did a lot of Zip cutting with them. As we went through them, we found the newer ones would have greater amperages (more power) at the same weight but would burn out faster.


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## martik777 (Jan 8, 2019)

Repacking those heads is a waste of time, all the grease flies off the gears in seconds. I checked after repacking mine.  The gears in his are probably bad from the factory.


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## Duke (Jan 11, 2019)

I have not returned the grinder yet - curiosity got the better of me and I opened it to take a look at the insides.

The gearbox had a lot of grease, but there was absolutely no sign of grease on the mating surfaces of the gears, so I distributed the grease around a bit. I agree that the grease will probably get thrown off pretty quickly but this should not hurt.

I opened the body as well and checked the connections - nothing visibly wrong.

After this I tried it for a short while and it seemed better.... Maybe just my imagination, but let's see how it holds up.


Talking about cheap tools - I also have a small ryobi belt sander - the one with the belt on the left and the round disk on the right.

The first one I got immediately made a weird noise. Returned it and got another one.

The second one has been going strong for the past four years without any problems and it has really seen a lot of use.

It looks to me like luck plays a part as well....


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## martik777 (Jan 11, 2019)

Was there any binding when you turned the hears by hand?

Could be one of 2 bearings too, here's a video:


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## gwade (Jan 11, 2019)

I have given up on Ryobi tools.  All i have tried have been junk.  I got tired of carrying them back.  I now stick to Dewalt or Metabo grinders.


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## Downwindtracker2 (Jan 11, 2019)

When the company was shutting down, rather than wear out my good Walter grinder, I bought a $29 on sale Chinese made Hitachi . I knew I wouldn't be getting any replacements from the company. It survived cutting out the machinery, and I'm still using it in retirement. It's lighter and smaller than my other grinders.


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## pdentrem (Jan 11, 2019)

Ryobi belongs to one of the big box stores? Lack of lube/grease and poor quality brushes are the main killer of these cheap units. Had a old Milwaukee that was rebuildable, sold it after years of use as I had no further use.


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