Old box fan and 'Lectric Motors 101

[Puddin' Man]

Re: Old box fan and 'Lectric Motors 101

IIRC, I used to know a bit about Electric Motors. That was back around 1970, and my memory is poor.

They must be building them to last. I haven't needed to work on one in many years.

But, when it rains, it pours. Now I got 'bout 3 EM's that might need repair.

One is an old K-mart box fan (a Lakewood K-223) that's gave good service for maybe 30 years. I even built a little stand for it ...

So I turn it on hi yesterday and after a few seconds I got a pop and spark out of where the wries enter the motor, and it stops. Today I clean 30 years of crud from the windings etc, reassemble, and test on lo. It runs for 20 secs then does the pop/spark again (and quits). I unplug quickly.

Here's the 'Lectric Motors 101 part. There's windings, brushes, and a rotor inside? Long time ago, it was practical to replace brushes as necessary for some EM's. What do you look for? What can you do/not-do?

It's a shot-in-the-dark, but I'd like to keep the fan going if possible.

I guess this is not a query for folks who pitch/buy- new without thinking about it. Might be a question for a good terminal tinker ...

TIA, Puddin'

[Colbyt]

30 years ago they built a real motor into those box fans and sold them for $25 or so on sale. 30 years later you can buy a new box fan for $12.

You may be able to find a universal motor at Grainger's or some place similar for $50 or so.

I doubt they are replaceable brushes or parts in you motor.

My advice. Pitch and buy. Use for a few years and repeat the process. It is the American way.

Colbyt

[I-zheet M'drurz]

I hate to agree because I know you asked for folks who don't think like that, but every single word in that reply is true. Do-it-yourselfers are losing the touch (through agg attrition) and there just aren't many neighborhood fix it shops anymore, and manufacturing has turned to a throw-away mentality. Make it cheap, sell it cheap, sell 'em another one two years from now.

I have a "$750" Sony 27" TV sitting in my living room that is probably 20 years old. Last time I had it serviced, Sony's flat rate was $225, I shudder to think what it is today. I can buy a new 27" Sylvania/GE/RCA (not no-name junk) at WalMart for less, I'm certain.

[dbird]

a fan will not have a motor with brushes..... a K-mart box fan coat about $12.00. go out and buy a new one.. i got two that i put in my garage windows(side window) to keep the air moving from the open garage door... they dont last forever..... when they break i throw them away, and i dont throw too much away(like to fix stuff just for the fun of it.. but those motors are so cheaply made that you not gonna fix it)..

[davefr]

Just about all fans, except for the little DC/Univerals fans, use split phase induction motors. There are no brushes in these motors.

I've restored 100's of old fan motors and most of the times the wiring gets frayed and breaks off right where it enters the motor case. (this is especially the case with oscillators).

Fan motor repair usually involves taking the motor completely apart and replacing any old wiring, reinsulating the stator, cleaning the rotor and bearings. You should also clean out the old grease in oscillator gearboxes.

Here's a good link:

[Curmudgeon]

No brushes. You can replace it for less than $10 right now at Home Depot. Learn to say goodbye.

[zxcvbob]

Fan motors don't have brushes.

Bob

[Puddin' Man]

Thanks once.

Thanks twice.

I got the back off the motor but could find no frayed wires.

I couldn't even get the damned fan blade off. There's a clip between the blade and the front of the motor. Maybe requires a special tool? Know any tricks to get it off?

Thanks a third time.

And a fourth.

I didn't see anything on how a DIY guy might wrestle with the motor internals. Is it there? Do you know of another info source?

To the other respondents: I got plenty cheap junk around the house. Bought the $12 fan y'all described 2 years ago. The thing vibrates, trembles, almost blows it's po' self over. Blade was out-of-balance when they put it in the box. I didn't have it a week before plastic parts started breaking. And it was a Lakewood. If possible, I'll repair the 30 yr old Lakewood.

Profuse thanks to davefr.

Cheers, Puddin'