Electric motor repair challenge

cathead

CATWERKS LTD
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It turns out that the first use of my newly made welding wasn't even for welding at all.



My project for the day was to at least make an attempt to repair a 5HP 1740 RPM motor. On disassembly, it was
found that the bakelite(or phenolic) ring that releases the starting winding switch was laying on the bottom of the
motor in three pieces. I know I could probably find some parts on line but decided to do a repair challenge
instead. First, I used some cyanoacrylate glue to get the part into one piece. I could see that it needed to be
beefed up a bit or would likely disassemble itself again due to centrifugal force. I used the vertical mill to make an
aluminum ring and drilled some small holes in it strategically and mounted it to the phenolic ring. Also needed
was a small clip to hold the ring onto the three clips that hold the thing in place. I used some tiny hardened counter
sunk rivets to hold everything together and reinstalled the rear bearing which I had removed earlier to get at the
repair area. It's all back together and seems to run just fine so I'm thinking it might work on my big air compressor
that will be powered by a 6500 watt Honda generator. I do not have the original motor but likely it was a 3450RPM
single phase motor. That will allow the 80 gallon compressor to run at half speed and also have a better chance of startup
due to the lower RPM.


The top photo is the aluminum ring attached to the phenolic part that was super glued together and below that is the flip side.
The third photo shows the repaired piece installed on the motor. I did a little sanding on the side that contacts the switch to
be sure that there were nothing protruding that would cause problems.

So that's my first adventrure of the day and on to other things, maybe even some welding...:rolleyes:

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Yesterday I mounted the 5HP motor on my two stage Sanborn compressor and powered it up with my 6500 watt Honda generator.
It didn't like the starting load but ran fine if I loosened the belt and let the motor spool up first. So at least it is usable as is and maybe
I can reduce the motor pulley a little so it will be self starting. It's an 80 gallon compressor so holds a lot of air as it cuts off at 175PSI.
 
Yesterday I mounted the 5HP motor on my two stage Sanborn compressor and powered it up with my 6500 watt Honda generator.
It didn't like the starting load but ran fine if I loosened the belt and let the motor spool up first. So at least it is usable as is and maybe
I can reduce the motor pulley a little so it will be self starting. It's an 80 gallon compressor so holds a lot of air as it cuts off at 175PSI.
Just provide a larger volume between the compressor and the check valve before the tank.
A larger diameter tube, or the easiest is a longer tube. Doubling the length usually works. It gives the motor more time to get to speed before it is loaded.
 
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