Loose Shaft on Small Fan Motor (photo)

[Quest]

folks, chill.

Nobody died in search for a replacement topco motor for sleddriver.

While I must say that I'm flattered with the complements on this, fact is, I can be wrong for 1/2 of the time also...age hasn't been all that graceful to ma brain.

Let's sit back and enjoy the thanksgiving? @ sled: good luck finding a replacement motor....

Take care ya'all.

Q.

 

[sleddriver]

Originally Posted By: JDenyer232
Like someone here said there is a loctite product for securing loose shafts in a bore. We use it all the time at work where I am a machinist to secure shafts that can sometimes transmit several horsepower. There is really nothing special about that motor, it is a simple shaded pole motor. If you have a local grainger you may be able to bring it in and have them match it up for you. The loctite # is 680 and is available from stanley supply for $16.54 if you want to give it a try. It is permanent so make sure you get the shaft where you want it before it cures or you will be SOL. Also there is a place called repair clinic dot com that has all kinds of appliance parts, you maybe able to find it there. Hope this helps. According to this site they have them is stock for $29. http://usaappliances.maxkiner.com/taxonomy/term/189/0


Thanks. I do have some Locktite Red. I'm curious if this would work? This little motor only draws 1.9A, so not much torque.

 

[Quest]

worth trying, sled.

Give it a try first and see if it comes loose after a short period of time (more worry about it breaking loose again due to thermal-cycling).

Q.

 

[sleddriver]

Originally Posted By: Cujet
As silly as it sounds, JB weld is an excellent epoxy for electric motor repair. As it withstands heat better than most commericial epoxies. And, better than most forms of loctite. With the possible exception of "high heat" loctite.

In fact, a quick view of JB Weld's specifications put it on par with some current aerospace adhesives.

If you need an "emergency repair", use the standard JB Weld, and let it cure for at least 24 hours before use.

Good idea! I may have some laying around.

Thanks for all who chimed in with suggestions and ideas. My apologies again to YY for mis-interpreting his post. I really DID want to take advantage of the wide, diverse skills and knowledge of fellow BITOG'ers...thus my post.

I'll have more time tomorrow to attempt a fix.

Happy Thanksgiving!

 

[sleddriver]

Originally Posted By: bvance554
How many watts is that 28 year old microwave?

I think 1200W...maybe 1300W. Meant to make a note, then forgot while fixing it.

 

[sleddriver]

Update:
Worked on it this afternoon and she's back to blowing. After weighing my adhesive options, I went with what I already had: 5min. epoxy. I let it cure for about 45min while I was doing something else. All the torque is now being transferred to both of the fans and they really move the air. Heated a glass of water and all is fine. Looking forward to having her back in operation.

Thanks to all who chimed in. I now know what a C-frame motor is.

 

[Vikas]

Quote:
Heated a glass of water and all is fine. Looking forward to having her back in operation.
This I don't understand. How is that a valid test if the squirrel cage has all the power from the motor?

 

[sleddriver]

Originally Posted By: Vikas
Quote:
Heated a glass of water and all is fine. Looking forward to having her back in operation.
This I don't understand. How is that a valid test if the squirrel cage has all the power from the motor?


Be sure I re-connected all the wires.

 

[PandaBear]

At 28 years old, it may have worn out most of the parts. If I were you I'd start shopping for a replacement, at least window shopping, just in case.

Was it on the original magnetron tube?

 

[Vikas]

I misunderstood your test. You tested your microwave to make sure it was heating the water (but that was not broken anyway) and also verified that no unusual noise were coming from the fan.

This is because I am under impression that the plastic squirrel cage fan's job is just to move the air and not aid in any way as far as the magnetron is concerned. Or does magnetron stops working if there is not enough air-flow?

 

[sleddriver]

Originally Posted By: PandaBear
At 28 years old, it may have worn out most of the parts. If I were you I'd start shopping for a replacement, at least window shopping, just in case.

Was it on the original magnetron tube?

Yes. The wattage is 1500W.

 

[sleddriver]

Originally Posted By: Vikas
I misunderstood your test. You tested your microwave to make sure it was heating the water (but that was not broken anyway) and also verified that no unusual noise were coming from the fan.

This is because I am under impression that the plastic squirrel cage fan's job is just to move the air and not aid in any way as far as the magnetron is concerned. Or does magnetron stops working if there is not enough air-flow?

The antenna is mounted on a large dia. plastic "fan" that is turned by air from the blower that first passes through the magnetron to cool it. Without sufficient air-flow, it would overheat, especially on high-power.

If the antenna doesn't rotate, then whatever you place inside won't evenly heat or cook. Particularly on an old one like mine without a rotating tray in the bottom.

 

[sleddriver]

Originally Posted By: doitmyself
A quick fix might be to remove the shaft, deform it, then push it back into the rotor. By deform, I mean to punch it with a center punch numerous times or squeeze it with some good sharp regular pliers around the shaft to deform the metal so that it becomes a press fit into the rotor.


Update: This turned out to be key, as the epoxy didn't hold for long unfortunately. This time I used a file to bear down on the center of the shaft and roll it back & forth across my bench. This significantly ruffed up the shiny-smooth surface. However, this alone wasn't enough to ensure a tight fit. So out came the steel center punch and I dimpled the shaft in several places to 'raise' some metal. This worked very well. I decided to dispense with epoxy this round. We'll see how it works over time.

Turns out Grainger had motors that looked similar, but didn't have double shafts. I called 10 local appliance repair/parts businesses, found one that had the motor for $69...in another state. On-line turned out more sources, but several couldn't put their hands on it when called to verify.

Thanks to this exercise, I now know what to do next time I discover a loose shaft...

Thanks to all. Merry Christmas and Happy Hanukkah!