Mill drive motor died.

[devinchi]

Well, after a slow decline over the past month the 1hp motor on the mill head of our Bridgemill finally got bad enough so we can't run it anymore. With the help of shoptask on the phone we haven't been able to remedy the situation, so it has come down to us needing to send the motor back across the country to vegas for them to work on it.

SO in the meantime, since we don't know how long it will take, and we have stuff to run, we have ordered a new motor from Grainger which should be here today. Our fun continues....

[Al_The_Man]

I take it its just a standard ac induction motor? don't you have any motor rebuilders closer to you?
Al

[Bloy2004]

Did you determine just went wrong in the motor? what caused the growl? A bearing or something allowing the armature to rub on the stator?
Does Shoptask pay for ALL shipping in returned and received?
After seeing a couple conversions of the Shoptask to DC variable speed motors, eventually mine will go that route.
curious geor..er John

[devinchi]

Well the motor that the machine came with is a medium quality Metric framed motor. It is set up as a washdown motor, so it is completely enclosed.

We believe there is a problem with the clutch for the starter winding, but are unable to find a problem.

There is a motor re-builder nearby, but we felt it quicker and easier to just get a new motor.

We were unable to find a metric replacement for it, so we went to a US speced 56 frame motor which thankfully the mounting surface is also drilled for.

This motor is great, well worth the investment, we were SHOCKED at how quiet it is in comparison to the original even when the original was working well.

My boss who is VERY tight with money walked by and made one comment.....when are we ordering one to replace the lathe motor!!!

At the moment we only have the new motor setup to run in one direction, in the next couple of weeks we will re-wire the 2 main motors to run off controls on the computer, and will completely bypass the stock buttons, this will also allow us to have the emergency stop button stop not only the main motors, but the CNC's as well.

[jazzenjohn]

One thing to check if your motor dies or hums and won't spin up is the starter capacitors. The cheap and easy solution I used was to remove power from my machine. Took the caps out of the motor being careful not to touch both contacts at the same time or shorting them out before I removed them. Checked the sizes and marked the wires. My other motor worked so I switched the caps to see if that was the problem. Reconnected the "bad" motor with the known good capacitors. It then worked fine, so I found similar (though they weren't exactly the same) sized caps from surplus and replaced them with new caps. Similar meant similar capacitance, similar size, and similar type.
Disclaimer: Don't attempt this if you don't have some basic understanding of electricity.

[qmaxbob]

My mill motor died repeatedly. The internal starter-circuit points keep welding itself and to run like that is horribly loud and will burn up the motor. I see that Devinchi found a replacement. Details please!!!!

BTW, I tried the replacement from Grainger that was recommended by Shoptask. Required drilling on the Shoptask frame. Also the pulley they recommended didn't fit...spacing between the pulley tracks didn't match that of the existing pulleys.

Only option now is use the original and that seems like a non-answer.

[jazzenjohn]

I don't know if this is any help for your problem but I found that the starter caps on my motors would go out and I had success replacing them with some I found on an electronics surplus website. I that's not it you may be able to take it to a motor repair/rebuilder. I've taken spa motors to them and they were reasonably priced for their repairs. Good Luck.

[qmaxbob]

Jazzenjohn,

Funny you should suggest that. I just went for a walk and realized that the capacitors' function is to keep the points from welding...duh... I'll give it a try. Thanks for the dopeslap!

Bob

[balsaman]

Actually its job is to get the motor started in most cases, and if the start cap is bad the motor usually just hums when trying to start and/or blows the fuse.

Eric

[qmaxbob]

Thanks for the input. I'm no electical whiz but I seem to remember from my motorcycling days that a set of burnt points was caused by a shot capacitor. I'm simply translating. I've got a e-whiz buddy I'll bounce it off of. Thanks, Bob

[DAPTS]

Capacitors are available from Grainger's. Burned starting contacts can be caused by bad capacitors, but poor supply current is a major problem. I suggest that a heavy single circuit line to the machine directly from the circuit breaker panel, 12 ga up to 40 feet, 10 gauge for a longer run.

[Mike Ichino]

Try this company.

http://www.surpluscenter.com/