Convertible Maintenance Questions

[broomvac]

Hate to say it.

I would not have sanded the upper bearing surface on the shaft. Not only will the diameter be smaller now (more play), but the shaft surface will likely never be as true or as smooth as it was before. If the surface is not as smooth as it was before, any bearing, new or used, lubricated or not, has the potential to wear out the bearing more quickly now.

But do not panic. Although it may be less than ideal, I'm sure it will last just fine. Replace the upper bearing if you want, but If you have already lubricated the original one and it doesn't sound or look terrible, the original should work just fine too.

The honest truth is, it's a pretty robust vacuum motor that is likely never going to see enough use to wear out any of its components ever again. Use it to your heart's content, let the motor break in after all the work you have performed on it, and enjoy your Hoover. I would be surprised if it ever failed you.

 

[real1shep]

You need to burnish a shaft, rather than sand it, I agree.  But putting a blackened shaft end back in from long use is not ideal either. It's easy enough to mic a shaft too, to tell if you've taken off material residue or actual shaft material. The real wear is most likely in the sintered bushing....considered sacrificial by design.


 


I doubt however if the tolerances in this case are that critical.


 


Kevin


 


 

 

[vacuumlad1650]

The reason an upper bearing will be stiff is it has not been seated. The original bearings wear down from Round to an Egg shape. You don't want to give an armature spinning at 7000rpm the opportunity to shift back and forth.
Install the new upper bearing, and then rotate the fan by hand. Then, while spinning the fan as fast as you can, give the upper bearing some decent smacks with a rubber mallet. This will seat it, and allow the motor to freely spin with no resistance. Make sure the felt pads around the bearing were soaked with the proper oil (i use 3-in-1 MOTOR oil) so it will continue to self lubricate.

 

[hooveru4089]

I take it that I need to lubricate the new bearing before installing. Is that correct?

Once again, thanks for all your help.

 

[vacuumlad1650]

I always put 2 drops of the 3-in-1 MOTOR oil in for good measure. Just allow it to soak into the bronze for a few minutes before installing it.

 

[real1shep]

Agreed...always 'prime' a sintered bearing like that....then the wick oil will take over. Just make sure the new sintered bushing you use isn't the 'dry' lubricated type.


 


Kevin


 


 

 

[hooveru4089]

Here's another update:

I replaced the top motor bearing temporarily with a known good used one and lubricated it. The motor is even noisier now. It sounds like a sick cow.

While running, I turned the lights off in the room to look at the sparks on the brushes. One brush is shooting sparks like an angle grinder on metal while I can't quite see anything from the other brush.

 

[real1shep]

I thought you replaced the sintered bushing with a new one? Or are you talking about greased bearing? Sintered bushings wear in relation to their shaft.....you can't usually pop one out of another motor and put on a different shaft....or at least it's not good practice. 


 


I think most of the noise sounds like it's might be coming from your brushes....they're not seated correctly if you have sparks coming out one side more than another. You can buy a commutator stone online for about $5. I just bought two from a dealer who sells Kirby stuff online. But you have to use it with the motor running for best results and depending on the motor access, that can be a bit twitchy...plus, you have to be mindful not to touch any part of the motor with your hand near the brushes because of the shock potential.


 


You really need an Elmer in this to show you the ropes....keyboards don't get it. That's probably why some here said to leave things alone.


 


Kevin


 


 

 

[hooveru4089]

Commutator stones would indeed be tricky. It looks like the only way to do this would be to run the motor with only 1 brush. My only other option would be to connect a drill to the armature and run that, as I had done seating the brushes.

 

[hooveru4089]

Check out the first picture in this thread. What do you think of this?

http://www.vacuumland.org/cgi-bin/TD/TD-VIEWTHREAD.cgi?18966__0#start_18966.383876

 

[real1shep]

Best way is to access the commutator while everything is in place.  Stonning it that way works to seat the brushes. Maybe that's why that hole was drilled...dunno. If you can get to the commutator somehow by shaping the stone or drilling a hole....that would be the best way. Stones are like $5 for small ones.


 


Kevin

 

[hooveru4089]

Where in particular are they most readily available online? I've seen few listings on Amazon for bulk quantities but not much.

I think I will probably end up drilling a hole and plugging it up somehow with a plastic plug or cap.

 

[real1shep]

Curiously, they are now $8.90ea...they were around $5ea just a few weeks ago. Plastic or rubber plug-great idea for the hole.


 


Kevin


 


 


 


 



http://https//www.ebay.com/itm/182980474616?rmvSB=true