AC motor request.

[Nick Sturtzel]

Hello. I'm trying to find a decent size AC motor for a project Tess is working on. Does anyone have one I could buy, or know a place I could purchase one used?

Thanks!

[Dan Bowen]

RPMs, estimate of horsepower?

[Nick Sturtzel]

I think 1/4 to 1/8 hp or more might be fine? As for RPMs, i think we'd be good with something around 3500 or lower. It's hard to give precise numbers, since this project is fairly flexible.

[Jeff Johnson]

I had dropped off an old garage door opener.  Its slow moving though.

[Aaron VerDow]

I thought there was one in the boneyard... it might be three phase tho.

[Raj]

Depending on your application, you might be able to use a corded power drill from Harbor Freight or similar.  This one http://www.harborfreight.com/power-tools/electric-drills/3-8-eighth-inch-variable-speed-reversible-drill-3670.html in particular is about $19, and goes from 0 to 3000 RPM.  According to this online calculator http://www.onlineconversion.com/motor_horsepower.htm , which assumes a %65 efficiency from the rated wattage, it is capable of 1/3 HP for continuous use.

---

From: Nick Sturtzel <gigasturtz@gmail.com>
To: lvl1@googlegroups.com
Sent: Wednesday, April 4, 2012 9:48 AM
Subject: Re: {LVL1} AC motor request.

[coffeebug]

I can probably land you a used one, depending on how soon you want, and you wouldn't get to pick the horsepower, the mount, the RPM.
I can buy you a new one for $80-90 from an HVAC distributor, they get Chinese motors for not too much money, you'd get to pick your horsepower, RPM, voltage, mount, etc and be able to replace a bad one with the same. 
You need to have the correct load on it, eg, at the stated RPM, the load should be adjusted so the amp draw is about that stated on the label.  It'll burn up if not loaded properly. 

[Nick Sturtzel]

Well, it turns out what we really want is a dc motor, or at least an AC motor we can adjust. Tess got a 2 hp, 3450 rpm motor and its just too fast. We would need to get something very soon, its for an art show that opens Thursday.

[Dan Bowen]

Ok, I recommend trying to estimate two things Nick which will help in finding a motor immensely:

SPEED in RPMS that she needs (roughly)

Torque required: measure it the old fashioned way if you need to, slide a 2foot-long stick through the end of the wire you're twisting so 1 ft is out either side.  Leave the existing motor connected but TURNED OFF. Turn it by hand through the entire range of torque you need, and use weights or a fish scale to measure the force exactly 1 foot out on the lever stick.  This will give you the torque in FOOT-POUNDS (ft-lbs).  

Use this chart by drawing a straight line from RPM through TORQUE to end at the HORSEPOWER you need.  

Knowing these three figures (or a range of them) will help you immensely find a solution faster.

Thanks,

Dan

[Jim Fry]

I have a DC motor.  I'll try to drop it by the space after church tomorrow.
It's got a 1/2" shaft.  It's gonna need a wicked power supply, it's from a house furnace blower.  Will stay online tomorrow morning.

[Nick Sturtzel]

Excellent! When do you think you might be by tomorrow? Are you giving it away, lending it, or do you want some money for it?

Thanks!

[Jeff Johnson]

Other possible DC motors that could work would be junkyard starter motors or windshield wiper motors.  Not sure if it would meet your torque/speed req's tho.

[jesco w]

i have some dc motors an ac motors ,,        my ac motor i can give you  is from a microwave oven ,, its like 6 rpm 120ac 2.4 watts         ,   dc is have a stepper motor that runs at 12vdc i believe an its 5 wire .   im not sure its max rpm
  
    also have anouther Ac motor from a vac cleaner  originally used it for a vac table but since found a bigger one from a shop vac.     


       any of these sound usefull its yours !