View Full Version : OT problem with some motors
Your Old Dog
07-15-2007, 01:38 PM
I've been busy Googling the "Philistine" crack trying to make sense out of it. In the process of searching I'm getting myself worked up and have need of my fans.
I have a couple of fan motors that start up painstakingly slow and I'm worried about burning up the motors. Using electric motor oil doesn't seem to do much. I suspect that years of cigarette smoke or some other type of gunk like oil turned to varnish is the problem.
Anyone know what might work well on a fan that won't require taking them apart. One is a magnificent antique 10" fan that still operates and is whisper quiet. Mounted it on the wall by my workbench to keep my stink blowed off me.
07-15-2007, 01:52 PM
You would think basting them out with some good electrical cleaner would do the trick.
07-15-2007, 01:53 PM
I have a set of high quality caster wheels that were installed in the 50's. The wheels were very hard to turn and squirting in oil didn't help. I had to pull them apart and clean the axle shafts and bores. After that they were like new.
07-15-2007, 01:55 PM
Almost certainly sticky old oil and wear particles in the bearings. after a while they heat up and some new oil is exuded, or the viscosity changes with heat.
You can try getting new lightweight oil into the bearings, and it may work.
Moer likely you will have to take them apart and clean the oilite with a solvent and "q-tips" type swabs before re-oiling.
I have a couple that take a minute to get up to speed. Need to get a "round-tuit".
07-15-2007, 02:12 PM
Give Kroil a try. Its what WD40 wishes it were.
07-15-2007, 02:16 PM
Putting in a "non-lubricant" is a bad idea, it displaces the lube, and may increase wear drastically. Better to take apart and clean.
Putting in a light oil is OK, but also not as good as cleaning.
Your Old Dog
07-16-2007, 08:00 AM
Looks like I'll try dismantling them and cleaning them by hand as opposed to using a spray type cleaner/solvent. I found some spray brake cleaner on sale at NAPA so I'll try that first and hope it don't dissolve the shellac in the motor windings.
On the bigger one I had tried simply re-oiling it with electric motor oil (3 in 1 brand) and it worked for a few days and then gummed up again.
07-16-2007, 08:13 AM
Take the blade and guard off
run the motor in a bucket of kero
blow out with air
oil and re-assemble
07-16-2007, 08:59 AM
Read the parable The Good Samaritan
The good news is that they won't likely burn out even if stalled. Most fans use shaded pole motors that are self limiting in current consumption. They are what is called "impedance protected" and won't draw enough current to smoke at any rpm including zero. Having said that if the magic smoke does come out don't send it to me. :)
07-16-2007, 10:13 AM
I've used type F atf to free up motors that were gummed, it seems to dissolve the sludge and wash out any crud while still providing a bit of lubrication, and oil doesn't seem to have a problem displacing the atf afterwards.
My garage fan is over 30 years old and still runs as well as new, doesn't look nice, but that's how I manage to keep it as a garage fan.
07-16-2007, 10:33 AM
The good news is that they won't likely burn out even if stalled. Most fans use shaded pole motors that are self limiting in current consumption. They are what is called "impedance protected" and won't draw enough current to smoke at any rpm including zero.
That can be true, and is in many cases.
But it is NOT in others. I had to replace a fan motor in a reasonably small "hassock fan" because my wife (who normally is good at such things) didn't see it as unusual that it ran slow and started slow, and never mentioned it. A few drops of oil would have fixed it, but instead the motor burned out in a very smelly manner.
There isn't a lot of consistency as to at what power level the fans move from shaded pole to regular induction motor. Very small are usually shaded pole. Desk fans can be either. Window fans are usually induction, often capacitor run.
07-16-2007, 12:13 PM
Perhaps something like this?