# Motor question



## SandCem (Apr 4, 2017)

Hi All! Sandric Cemetery here (Sandcem). I recently received a high RPM motor that was used for an air conditioning dehumidifier. It spins around obviously but at a fast rate. Any ideas on how to slow it down, any other suggestions?

Thanks!


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## David_AVD (Nov 9, 2012)

Is it a 120V AC or low voltage DC motor?


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## SandCem (Apr 4, 2017)

It is 120V AC - 3,000 RPM


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## David_AVD (Nov 9, 2012)

If it's a synchronous AC motor you're pretty much out of luck.

"Universal" AC motors as used in corded drills are controllable, but still not trivial.


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## corey872 (Jan 10, 2010)

Possibly something like this jewel?

https://www.ecmdi.com/utility-blower-motor-kit-120vac-3000-rpm-supsm670









I have seen these with gearboxes attached - which is the best way to slow one of these down... as a shaded pole motor, they have virtually zero torque anyway, and trying anything electrical to slow it down just makes the torque problem worse. At least the gearbox can net some torque multiplication. Though conversely, I have never seen the gearboxes for sale separately - it's always built into the frame of the motor.

You might be able to scavenge around and find some gearbox somewhere, but be careful... you may spend months of searching and a $15-20 gearbox that may or may not actually fit your 'free' motor. Or you could likely get a different motor of the rpm you want for cheaper at some surplus outlet.


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## SandCem (Apr 4, 2017)

Hey thanks for letting me know.


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## SandCem (Apr 4, 2017)

Yes, it's definitely a pole motor. Thanks for the helpful info. seems like it's useless but it was free so no loss


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## corey872 (Jan 10, 2010)

Well, I would not say 'useless' - it just needs to have a use in the present 3,000 rpm form. Possibly a fan for ventilation, blow fog around, or create a slight breeze where needed, blow silk 'flames' in a cauldron fire? Hot glue a small mirror parallel on the shaft and create a laser line scanner, or glue one with a slight wobble at the end of the shaft and create a laser vortex generator? micro axworthy ghost driver? bolt a small offset weight to the shaft and make a vibrator / rattling noise maker?


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## imax (May 22, 2006)

Slow it down using standard reduction techniques. A 1" pulley or gear on the motor shaft linked to a 20" pulley or gear via belt or chain will give you a 20:1 reduction (new rpm is 150). Repeat until desired speed using various gear/pulley sizes. Bonus: reducing speed increases the motor load capacity.


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## SandCem (Apr 4, 2017)

*Good suggestions*

Thanks for all those suggestions, definitely did not think about the laser or vortex usage.


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