In need of a 1 1/2 HP slow speed motor

[Scott Brandstetter]

I am wanting to build a drum sander from plans I have and it calls for the motor above. Anyone have a source for motors that are not obvious. Harbor Freight has a motor but it is "compressor rated" which I understand means it cannot be run for any length of time. I've looked at ebay but I feel I just won't know what I buy until i get it. Just thought it was worth a chance to ask. Any help appreciated

[John T Barker]

I see a bunch on craigslist...sometimes new. You could also check the "yellow pages" for a motor repair shop, they're sure to have some on hand or a source. 1-1/2HP for a sander? Seems excessive, not that I'm an expert.

[Cary Falk]

I have had good luck here. http://www.surpluscenter.com/Electric-Motors/.
I old beat up tools on the cheap through CL just to get the motors.

[Mike Henderson]

When you say "Slow Speed Motor" are you referring to a 1725 RPM motor? Or something slower?

I don't know what the design of your sander is, but you can do a lot with different sized pulleys to get the speed you want.

Mike

[Bill Orbine]

You are looking for "continous duty" motor. Motors rated for compressors isn't quite about the duty cycle but more for being able to operate under load most times as well as starting under load. A lot of compressor motors can be "continous duty".

[Bruce Page]

I can't speak to the Harbor Freight "compressor rated" motor - I've always been leery of HF's motor quality. I also have never heard that a compressor rated motor cannot be run for long periods of time. It has always been my understanding that CR motors are typically a higher quality motor that is designed for hard start applications. There are also applications where they are required to run for extended periods.
That said, dust is a motor killer. At the very least you should be looking at TEFC motors.

[John Blazy]

I made my disc sander from a 3 dollar (garage sale) washing machine motor. still runs great. Silent, direct drive. 1725 RPM. That appears to be the slowest you might find. So gearing (or pulleying) down would be smart. Direct drive slow motors are a job for McMaster Carr.

[Dave Cav]

As mentioned up-post, what rpm is called for? "Slow speed" can mean a lot of things to different of people.

One option no one has mentioned is to get a 3 phase motor and run it with a VFD. The VFD will let you run the motor at any speed you desire, and used 3 phase motors are cheaper, more simple and generally more robust than single phase motors.

[mark kosse]

As mentioned up-post, what rpm is called for? "Slow speed" can mean a lot of things to different of people.

One option no one has mentioned is to get a 3 phase motor and run it with a VFD. The VFD will let you run the motor at any speed you desire, and used 3 phase motors are cheaper, more simple and generally more robust than single phase motors.


and nothing beats a VS sander.

[Mike Henderson]

As mentioned up-post, what rpm is called for? "Slow speed" can mean a lot of things to different of people.

One option no one has mentioned is to get a 3 phase motor and run it with a VFD. The VFD will let you run the motor at any speed you desire, and used 3 phase motors are cheaper, more simple and generally more robust than single phase motors.
That's a good idea, Dave. Thanks for posting that.

Mike

[Bill Adamsen]

The 3-phase and VFD is a good approach. Another option is a variable speed DC motor with an AC/DC drive controller. My old Delta/Rockwell lathe is powered with just such a Treadmill rated DC Motor (free) and a Dart 250 controller. Speed is controlled via a foot pedal which connected effortlessly to the Dart 250.