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JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5

1 edit

Very low RPM motor

I'm to sure where to put this so it's gonna go here and can get moved (or left) as needed.

I need a small, quiet, electric motor that spins at maybe 10 - 15 RPM. I would probably prefer AC (120V) but if it has a low draw that can run on a 12V 7Ah or 14Ah battery for 8 hours then DC will likely work as well. I also need it to support a chain drive, bicycle chain to be specific (I don't know the exact chain size though). Does anyone know where I can find something like this?

Edit: it will need to spin about 30 pounds or so.



61999674
Gotta Do What Ya Gotta Do
Premium
join:2000-09-02
Here
kudos:1

I doubt you will be able to find anything like that that is direct drive(within your price range), you will probably need some type of transmission.
--
It is better to have it and not need it, than to need it and not have it.



Hydraglass
Premium
join:2002-05-08
Kingston, ON
reply to JoelC707

What you need is called a gearmotor - they sell them in places like mcmaster carr and grainger. You can pick the torque and RPM's - they will sell ones as low as 1-2 RPM, torque ranging from a few inch-pounds to many foot-pounds.

I'll go poke around on the McMaster Carr website now and see if I can find something appropriate and post you a link back here.

The motors "look" direct drive, but they actually have a gearbox built into the body of the motor.



tschmidt
Premium,MVM
join:2000-11-12
Milford, NH
kudos:9
Reviews:
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reply to JoelC707

As 61999674 See Profile posted to get speed that low you need to use a gearhead drive to reduce motor speed. You could use a stepper motor but they need electronics to drive them and would be pretty choppy that slow.

Here are a couple of places to check out:
»www.mpja.com/
»www.surpluscenter.com/

/tom


Langning
Premium
join:2003-04-28
Marlborough, MA
reply to JoelC707

said by JoelC707:

bicycle chain
said by 61999674:

you will probably need some type of transmission.
Put the motor on a smaller wheel.


Hydraglass
Premium
join:2002-05-08
Kingston, ON
reply to JoelC707

Half way down this page is the exact item you're looking for:
»www.mcmaster.com/#catalog/114/996

They have a 10RPM gear motor with 40 in-lbs of torque - if driving something through a chain with a small amount of mechanical advantage you could easily be getting 4-5 foot pounds of torque (that would "lift" a weight of 5 pounds at the end of a 1 foot lever - if you have a weight of 30-40 pounds balanced on a bearing without too much off-balance that would be plenty).

Hope that helps.


JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5

That looks good, I've got a Grainger near me so if I can get it there that might be a good option though online works just as well. Thanks for finding that.

I didn't realize until now that I can alter the speed by the size sprocket I mount on the motor so exact speed doesn't really matter. What we've created is a rotating display stand. We used the rear wheel from a bicycle for it's multi-speed drive (it'll click when spinning so I guess we'll have to deal with that). We welded a piece of 1" EMT to the end of it and using it to mount a gas motor and a few pieces of a bicycle in a partial mock-up that we want to slowly spin in the showroom.

Due to the heat of the welding (even with tig) several of the bearings dropped out and not all of the 7 gears spin but the largest and smallest gears still work. With a combination of the gears available on the wheel and the gear we put on the motor shaft, I think we can fine tune the final speed to our liking. Does this sound like it will work?



nightdesigns
Gone missing, back soon
Premium
join:2002-05-31
AZ
reply to JoelC707

Windshield wiper motor comes to mind. It's low RPM, variable speed and powerful.

I'm no expert on this, but saw it used on some TV show somewhere whey they were rigging something together.
--
This Space for Rent...



ttiiggy
Premium
join:2001-03-27
Bozeman, MT

said by nightdesigns:

Windshield wiper motor...
...TV show somewhere whey they were rigging something together.
I watch »www.redgreen.com/ too.