# Shopvac overheating!



## AaronK (Nov 30, 2008)

I was using my shopvac yesterday (6 gal size) hooked up to my router and it started overheating… motor slows down and it smells funny. Turning it off an on again, it works fine - there seems to be adequate air flow through the filter, etc - for ~10 seconds, then it gets bogged down and overheats again. It is still working, but I'm not using it again until I find a solution. yikes!

Any idea what this could be?

many thanks, 
Aaron


----------



## lew (Feb 13, 2008)

Sounds like the permanently lube motor bearings are no longer lubed. You may be able to disassemble it enough to put a couple of drops of motor oil on each end of the armature. while it is apart, blow out the motor with compressed air.


----------



## tenontim (Feb 24, 2008)

You don't have a hose reducer on it do you? If the air flow is reduced from the normal 2 1/2" hose to something considerably smaller, it will cause the motor to over heat. Also, make sure the check ball in the bottom of the motor is falling free of the outlet. Might have some junk in there keeping it from releasing.


----------



## SST (Nov 30, 2006)

Can we assume that the filter is clean? They can plug up quickly. -SST


----------



## AaronK (Nov 30, 2008)

thanks all for your replies.

Lew: i will give this a shot, since it sounds somewhat likely given that…

Tim: no, no reducer, and I did check that the ball is free to float.

Tom: yeah, i actually recently cleaned out the filter (well, dusted it out the best its ever been yet) and gave it another once over after this incident happened.

This does come after semi-intensive use - leaving it on for ~45 minutes straight while gently planing away some squirelly walnut… then cleaning the shop with it. Still, the thing should be built like a tank. anyway, ill get in there and see if i can get oil in the bearings. hopefully the windings arent fried (smelled like burning!)...

thanks again guys!


----------



## ajosephg (Aug 25, 2008)

IMHO most inexpensive shop vacs aren't designed for continuous operation. Also it could be just tired (worn out).
I used to own a fast lube place and we used Craftsman shop vacs to vacuum cars and they had a high duty cycle and many on/off cycles through the day. They would last about a year. At that time Sears had a life time guarantee so we just took them back and got new ones. I don't think they have that guarantee anymore.


----------



## AaronK (Nov 30, 2008)

yeah, that appears to be the case.

I opened it up and (of course) there is that one bearing at the end of the line (actually closest to top of the unit) that was funky. Siezed almost completely actually. Some oil worked in there is helping a little to keep it going, but I definitely will be looking for a new shop vac soon.

the burning smell was actually the plastic (!) fan that's attached to the main shaft which was getting really hot from the friction.

Anyway, problem solved. thanks again all for your help.


----------



## Bureaucrat (May 26, 2008)

I burned out a motor in a master mechanic shop vac. I have this thing about not throwing things away before their time; so I ordered a new motor. It cost a lot more than a new shop vac! 25 years later I still have it and have had to patch the holes that rusted through the canister. Aaron, glad to see you plan to replace it!


----------



## tenontim (Feb 24, 2008)

Aaron, by the way, Shop Vac has excellent customer service. I burned out a motor on a fairly new vac and when I called, the guy told me that ShopVacs don't burn out motors, and sent me a new one. Both of the motors occasionally have given off a burning electrical smell. I've been using the one, that I replaced the motor on for over two years, as a dust collector for my RO sander, which gives it quite a work out. I may have to check the fan on mine.


----------



## TopamaxSurvivor (May 2, 2008)

FYI, bearings and the starter switch are the most common failures in single phase motors. Generally speaking, you can feel some end play in a small motor shaft, but any lateral movement means bearing trouble ;-((


----------



## AaronK (Nov 30, 2008)

good to know. i've never had the opportunity (pleasure? hah) of dealing with motor problems before, so this is a new one. I will give customer service a call… the brushes have plenty of life in them yet, and the rest of the motor looked fine, so I just wonder why the bearing went so soon. oh well.


----------



## TopamaxSurvivor (May 2, 2008)

possibly bad when it was new ??


----------



## donbee (Feb 7, 2009)

Just one more thought - is it connected to an extension cord?

d


----------



## spaids (Apr 15, 2008)

I am a garage woodworker and as such have no room for real dust collection. I have a ridgid shop vac and the filter on mine would clog FAST. I found this company. They sell a cyclone filter for use with a shop vac and it works fantastic. Its a small company with outstanding customer service. I am in no way affiliated with this company but I have been so impressed with them that I promote them when ever I run into a a fellow shop vac'r. Nothing makes it past the cyclone filter and my shop vac stays clean and breathing well and sucking hard. The finer the dust the better this thing works.

But it some how your filter is not clogging then you have no need for this cyclone. I just can't imagine how you keep your filter clean.


----------



## AaronK (Nov 30, 2008)

It IS connected to an extension cord, but that bearing was definitely bad and that fan was definitely melting.

I'm not sure what caused it exactly, since it was working fine before. Again, I did work it hard for a while, and that could have heated things up a bit causing rapid bearing wear. I also found a lot of dust and debris in and around that area, which could have definitely accelerated things.

I did can ShopVac service and all they will do is send me a new motor for about twice the cost of a new unit. So actually i dont think i will be replacing it. I may cut open an access to the top of the motor housing to make cleaning out and oiling that bearing easier though and make it a routine maintenance procedure. I really dont use it terribly often though. Just for planing, some routing, and cleanup. All of which are really quite infrequent.

Finally, thanks for the link Spaids. Yeah, the filter was definitely clean enough for normal use - I couldnt detect any drop in suction pressure anyway. My shop is also too small for real dust collection. I set up a very crappy "cyclone" in a cardboard box to use with the planer since it throws out the chips. Something like that would be much more effective. Still, for my use I wonder how that compares to the garbage can attachment that Lee Valley sells.


----------



## TopamaxSurvivor (May 2, 2008)

That Lee Valley lid looks like something a guy coould make if he were ambitious and the tinkeriing type. For $45, you'd probably have that much in materials :-((


----------

