# Electric Motor Repurposing...



## Ripper70 (Nov 30, 2015)

Hey All,

I have come to acquire two (2) electric motors that I'd like to repurpose in my garage/shop.

Both motors are 3/4 h.p. at 3450 r.p.m. and were originally used as spa/pool pump motors. One is an induction type (assumed because of the capacitor hump) and the other, I believe is a DC motor.

I'm guessing that each could be used to power a disc sander or grinding wheel or some such machine, but I'm not certain. Do you all think these motors could be put to good use in a woodworking environment and, if so, what would your suggestions be for their best use?

Any comments would be greatly appreciated.

*This is the induction motor label:*









*These are from the DC motor:*


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## SamK (Aug 17, 2015)

Hi Ripper70

I do belive you can use both these motors in woodworking/metalworking applications.
If you wanted to build a disc sander you will probably have to slow it down with pulleys. 3450 rpm seems to fast for wood if you were able to get it down to 1800-2000 rmp you would get better results.
For the grinder 3450 rpm would be great for use with metal.
You can get really creative and make a bench grinder, all a bench grinder is a motor. They sell all kinds of attachments for bench grinder polishing wheels, wire brushes, or just plain grinding wheels all you have to do is attach them.
There are many other machines you can build it just depends on how much money and time you are willing to spend

Good luck
Sam


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## Tootles (Jul 21, 2011)

Just so you know, your "DC" motor is actually an AC motor - the nameplate says that it operates at 115 V / 60 Hz.


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## WoodNSawdust (Mar 7, 2015)

Tootles is right, the second motor is also a AC motor. DC motors don't give a Hertz (Hz) rating.


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## JoeinGa (Nov 26, 2012)

Yup, 3450 is WAY too fast for a disc sander, but for a grinder you can buy one of these adapters to fit the shaft at your local hardware store.
.
.


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## dhazelton (Feb 11, 2012)

Only issue you may have is that pool pump motors may not have end bearings that can take a heavy load, but I say go for it. The USA built Emerson is a good freebie.


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## Ripper70 (Nov 30, 2015)

Great information to have. Thanks for the insight, all.

Is there a way to slow the r.p.m.'s of either motor by way of adjusting the amount of power they receive or is a pulley/spindle setup the only way to do it? I think I can handle attaching accessories to the arbor but that's about as sophisticated a machine as I'm ready to build right now.


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## dhazelton (Feb 11, 2012)

No.

Small pulley on the motor and a large pulley on the grinder does what you want. Look for a mandrel that you can change pulley size on. Caswell Plating is a place that sells do it yourself buffing/sanding/grinding parts.


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## WoodNSawdust (Mar 7, 2015)

I would stick with the pulley & arbor technique. There are web sites that will help you calculate pulley sizes to get whatever speed you want.

A 2:1 pulley ratio and a double shafted arbor would give you a nice slow speed grinder. If you do this go with 8" wheels.

With an arbor and a threaded face plate you could build a 10 or 12" disk sander. The bearings in the arbor might eventually ware out due to the side pressure, but you can replace those.


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## Ripper70 (Nov 30, 2015)

> With an arbor and a threaded face plate you could build a 10 or 12" disk sander. The bearings in the arbor might eventually ware out due to the side pressure, but you can replace those.
> 
> - WoodNSawdust


I'm thinking that a disc sander might be the simplest tool that I could put to use right away but I'm trying to understand what would be required to do this.

So, I would attach say, a 4" pulley to the motor arbor and use a belt attached to a second pulley that was 8" in diameter mounted to a 12" sanding plate? Is that how it's done?


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## dhazelton (Feb 11, 2012)

In theory, but go with a 2 and 4 inch pulley. If you have a lathe you could even turn the pulley that you could screw directly to your sanding faceplate. Make sure you orient your motor and shaft so the direction of rotation is what you want. That may mean mounting the motor below the sander or behind and off to the side.


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## MrUnix (May 18, 2012)

As already pointed out, both are A/C motors… one is 120v only, and the other can be wired for either 120 or 240. Bearings should be pretty standard 6203-2RS deep groove ball bearings which would work fine for a disc sander if that is what you want to make. Only problem that you might encounter, and I can't tell from your photos, is that they usually mount to the pumps in an unusual way which may make things a bit more difficult. Typically, one end-bell has extended bolt holes that allow it to be bolted to the pump housing, and it is extended out further than typical to allow for the coupling to have room under it. Unless yours have some more standard mounts, you will most likely have to get creative as to how to mount it.

To calculate RPM's with various pulley arrangements, you can use the VIntagemachinery RPM calculator.

Cheers,
Brad

PS: If you have a pool service company nearby, they usually throw out those old motors by the pallet load… and most are good motors and just have bad bearings or capacitors. If you get friendly with them, they will let you rummage through the pile and pick out some that can be easily rebuilt. I have about 10 of them sitting out in the shed, ranging from 3/4hp up to 2hp  (also a good source for start capacitors!)


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## MadMark (Jun 3, 2014)

Both motors are AC, the tirst can run on 220v or 110vac, the 2nd 110vac only. Both are NEMA-56 frame motors with standard mounting bolt patterns. Try http://mcmaster.com they have everything for motor mounting, drive pulleys, etc.

M


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