View Full Version : Electric motor question

loose nut
10-21-2012, 04:36 PM
I need a new motor for the mill (RF-45 type), are WEG motors OK. The current one is 1 1/2 Chinese HP, would I need a "quality" motor that is also 1 1/2 HP or would 1 HP be adequate. Not a lot of places that cater to the consumer, over the counter non-business people, for motors around here. Not a lot of selection.

10-21-2012, 04:43 PM
Yes, their motors and VFD's are nice quality, V.J. Pamensky in Canada.

loose nut
10-22-2012, 06:39 PM
Why I might heed a new motor or what I did on my fall vacation.

A year or so ago the motor on my mill crapped out, took it in to get it fixed, turned out that the centrifugal start switch was stuck in the on position and burned out the cap. After it was fixed it ran fine, for a while, then started doing the same thing again. It would hesitate when starting and it would keep getting worse until yesterday it wouldn't start and tripped the breaker. Today I took it to the local farm equipment/electrical shop, this is farm country not the city, and he couldn't find anything wrong with it. When I picked it up it would start right as rain. The electrician said the inside look like it was brand new and the switch worked properly. After I got it home and back on the will I tried it, wouldn't turn and tripped the breaker. Second try it worked fine and has since but occasionally it struggles. The only suggestion the electrician had was that there could be something wrong with the mill but I don't think so, I can turn the spindle by hand very easily so the motor shouldn't have any trouble with it.

Any ideas.

P.S. the electrician wouldn't take any money for what he did so if I do need a new motor he gets the sale. Does hurt that the motors he sells (Baldwin) are about $100 cheaper then other dealer in the area.

10-22-2012, 07:33 PM
Traditionally R.O.C. motors are a source of problems, either capacitor failure or switch intermittent etc, I knew of one importer that automatically replaced the motors before resale.
Put a 3 phase motor and VFD on it.

10-23-2012, 09:48 AM
REALLY silly question. Did the motor wok fine for the electrician in the HORIZONTAL position, and give you grief in the VERTICAL position? If so, I would suspect the centrifugal switch; perhaps the sliding section is riding on a burr on the shaft. Maybe you could find a replacement.

Forrest Addy
10-23-2012, 10:05 AM
I wonder if the vertiocal installation has an effecton the centrifugal start switch?

10-23-2012, 10:16 AM
Does your power source check out to proper spec? Have you tried it at home on a different circuit?
A faulty switch, breaker or wireing between the two could be a factor.

loose nut
10-23-2012, 02:14 PM
REALLY silly question. Did the motor wok fine for the electrician in the HORIZONTAL position, and give you grief in the VERTICAL position? If so, I would suspect the centrifugal switch; perhaps the sliding section is riding on a burr on the shaft. Maybe you could find a replacement.

Yes it was on it's side but he took the motor apart and checked out the switch and said it was OK. The switch itself seem fine, I thinking that the cap is damaged to some degree and isn't doing its job as well as it should. I could (probably am????) be wrong.

Unfortunately these are not a standard motor, different size and length shaft etc. so a exact replacement is difficult to get, necessitating building a mounting adapter and a coupling for an off the shelf motor. Doable but a pain in the but.

Run to failure:eek: and replace.

10-23-2012, 02:39 PM
If you think the cap is bad, replace it first. They're cheap and easy to get. Might buy you some time anyway.

10-23-2012, 05:32 PM
I have a Lathemaster ZAY7045 mill, and pretty much the same experience w/ the motor that you had.

I made up a stub shaft and put a love-joy coupler on it:


Bought a cheap C-Face motor off Ebay, and gave it the love-joy treatment as well:


Then I made up this adapter on the lathe:


Not terribly elegant, but it is effective!


loose nut
10-23-2012, 07:25 PM
That how I was going to do it but with a homemade coupling. What brand of motor?

The guy I went to sells Baldor but I can probably get WEG or Leeson. Is there much of a quality difference, there all made you know where now.

I could go with a new cap first but this POS is really starting PMO.

10-23-2012, 09:00 PM
I believe Baldor are owned by ABB now?

10-24-2012, 09:51 AM
I've got a "US Motor", which I believe is formerly known as Emerson. It's no prize by any means. I've had the stationary switch replaced this summer as it was sticking. The good news is that the bill for that came to $30 instead of the exorbitant amounts I was paying to get the chinese motor fixed around here. But, I don't think it says "China" on it--I believe it's Hecho in Mexico, FWIW.

At a certain point ditching the chinese motor is worth it whatever the cost. . . . And, now I can just switch out the motor with anything off the shelf.


loose nut
10-26-2012, 07:05 PM
Well, I was just about to bite the bullet and go buy a new motor but first I called up a friend about his thought on how I was going to mount it. He has a mill very similar to mine, a RF-45 type but from a different supplier. Taiwanese not Chinese. Turned out he had replaced his motor with a 3 ph/VFD combo and had his old motor available. I paid him $140 for the motor, his help and gas money to drive to my place, half what a new one would have cost and without the aggravation of having to fit it. The new one is 220, instead of the 110 version I had before and appears to be much better made. Anyway I am back in the milling business.