Need help fining suitable replacement dc pm motor. Neither the original motor (a2d061) or one with similar numbers are avaible (90 volts 20 amps, 4000 rpms 2.25hp). Found some with less amps or 180 volts, but thinking I have to stick to the original parameters. Original motor makes a scraping sound at high revs and will eventually shut down. I thought it was the bearings so replaced them and still get the noise. Magnet looks good and no visual issues motor or windings. Would prefer to understand what is broken and fix vs replace the full motor, but wife wants this treadmill back up and running. I know there have been slot of postings on converting treadmill to lathe so hoping someone here can help me.

 

There are usually plenty on ebay. The Johnson ones are pretty good.
I assume you have had the motor apart, as often a field magnet comes loose and requires cementing back in.
But if only at high revs, there is no loose commutator bars is there?
Are you sure it is mechanical noise and not electrical of some kind?
Does the drive just shut off when the noise appears and requires power off and on to reset?
Max.

 

Can't find one that is 90v and 20 amps. I need to stick to those values, correct?

Not sure on the noise it's sounds like mechanical but if that was the case I would think given the rpms it would almost me a continuous noise so maybe it's electrical.
Yes, had it apart a couple times. The magnets are still attached so good there. I didn't check the bars other than visual and looked good. I can pull apart and check again tonight.

I'll also confirm on what happens after it shuts down, but I think I had to power off and on again. What would that be an indicator of?

 

The Johnson 2.25 is the right size, rating wise. Even the 2hp should work.
If you have a Variac you can test it on the bench through the rpm range.
Does it have any kind of RPM sensor mounted to the back of the motor?
Max.

 

No rpm sensor on the motor. Also when it shuts down i can start up again without having to power down the whole treadmill, turns out that is because I had the belt off. So put that back on and it continues to run. I did noticed as soon as I get on the treadmill it losses rpms and struggles like the hp is gone.

I found a Johnson motor, its 19amps vs the 20 amp one I have. Found a nautilus 20 amp 2.7hp but it's 105 volts. I don't enough about theses nd how they relate to each other to know if they will work and what I lose. I though I found a thread on that some where, will look again.

 

The motor is not that critical as long as the HP is close, it probably never runs at that current anyway, if you are in N.A. it is probably operated on a 15a outlet!
Max.

 

https://www.ebay.com/p/Sportcraft-A...-Turbine-DC-Motor/1703868165?iid=112683539703
One on that page

 

The tricky part when subbing a T.M. motor is many have a threaded shaft for the flywheel, some L.H. thread, some R.H.!
Max.