How do you clean up the guts of a motor?

[HMF]

So you buy a "new" old machine, and the motor is filthy, inside and out.

You know you can't just hook it up that way- cleaning up the motor is an essential part of the restoration. Plus, you worry the motor will smoke or catch on fire from all the **** inside.

Short of sending it to a motor shop to have them tune it up, how do you (a) open up the motor, (b) clean up the insides, (c) change the bearings if necessary, (d) tape up or otherwise prep the motor leads to be rewired?

Thoughts, opinions, techniques and tips PLEASE?

Thanks!


Nelson

 

[StonewellMark]

Try; CRC QD electronic cleaner. It works pretty good, can also be used internally in the motor as it leave no residue. It is great for cleaning greasy machines but is expensive at $6-7 a can at my local NAPA store!

Mark

 

[Tony Wells]

There are electric motor cleaning solvents that evaporate quickly and do a great job. Most come in bulk and should be dispensed with an air powered siphon gun. You probably could buy a bit from a motor rebuild shop.

It is nice to have a megger to see if the insulation is good, and the carbon is all cleaned out, especially on brush type motors.

Bradley wire markers are one way to tag all the leads, if they aren't already marked. If I tear down a motor, I will usually replace the bearings, unless it is a newer motor.

 

[HMF]

Tony,

Assuming a motor came in from an old machine, what would be your order of handling it?

If anyone had any photos of the procedure- that would be great. I know that there are a few videos on Youtube. I have seen them, but they move through the procedure a bit fast.


Thanks,


Nelson

 

[Tony Wells]

Well, I've done a few, Nelson. After removing sheave or pulley, open the "peckerhead" and make sure the leads are marked. It's possible that metal bands are used to id the leads. Just make sure you keep track of them. On some, with faint markings, I have taken single strands of copper wire from some THHN and making rings for each lead, marke them with 1 ring, 2 rings, 3 rings, etc., just twisting the wire around the lead.

Then take some abrasive paper or scotchbrite and clean the output shaft of anything that would interfere with removing the end bell.

Remove any brush holders and brushes, if that type of motor. Again, tag or mark all wires and connections.

Remove the long screws and nuts holding the motor assembly together. Be sure and match-mark all three pieces. I use a prick punch and put two small marks close to the mating edges so you can align things on reassembly.

Pull off the output end bell. You may have to tap it apart with a small chisel or old screwdriver. Watch for any washers, like wave or Belleville style, and their position. If this is a motor with a centrifugal switch, remove the other end first, disengaging and tagging all wires. Then proceed to pull the other end bell. Always watch for position of any spacers and washers. Remove rotor/armature.

Once disassembled, the end bells can be washed in a solvent, as long as there are no electric components attached. If there are, remove them. Knock out any seals after getting the number.

Now it gets interesting, and I can give only basic guidelines. Using an appropriate puller or press with tooling, remove bearings.

I would use mineral spirits myself if the motor was pretty dirty, then wash it down with an approved electrical parts wash. Dry thoroughly.

Reverse to assemble.

Tornado warning just came....think I'll take cover.

Edit.............lost power before posting. Back up this AM

 

[HMF]

Thanks Tony!

I have seen on the news you guys have a Tornado that touched down in the Dallas suburbs.

I am going to attempt to clean up a couple of motors. The motor shops that I get when I Google in this area are not close by, and shipping a motor is a PITA, plus, it is yet another thing to learn.

Best,

Nelson

 

[Tony Wells]

I'm about 100 miles east of Dallas, but we had some funnel sightings and a couple on the ground near me. When they said for people to take cover on a few roads either side of me, within 3 miles, I believed it would be prudent to do so. After all that blew through, I had no internet service until this morning. There were quite a few limbs down, and reports of some possible injuries in the area from what they said were tornadoes.

Oh, just don't use anything strong, like lacquer thinner on the motor. If you can get is, TSP will work good to degrease, but be sure and rinse thoroughly.