# What to do with these motors?



## drzeus (Jun 25, 2011)

Mabuchi RS-380sh motors-4535








I work in the medical field where we discard these things regularly.
As a haunter, I can't throw em away, so I have at least 50 of them.
Does anyone know how I can reduce the rpm's (to my liking) with these things and where to acquire the appropriate gearing?
I'll send 10 of these motors to anyone (continental US) to anyone with the best (cheapest (assuming the gearing is cheaper than buying the whole gizmo...)) links...
http://www.mabuchi-motor.co.jp/en_US/cat_files/rs_380sh.pdf


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## niblique71 (Dec 2, 2009)

I believe these are Brush motors, which easily makes them variable speed. A simple light dimmer should vary the the speed infinately. The torque however at low speeds is up for debate. THis should be a simple solution compared to an induction coil motor which needs pulse modulation to control the speed.


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## drzeus (Jun 25, 2011)

Thanx niblique.
Is there a gearing system available to reduce the rpm's?


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## niblique71 (Dec 2, 2009)

Well you can use gears etc... But what I was proposing was that a light dimmer to reduced the amount of electricity going to the motor (You know the ones you use to dimm the lights for a roimantic dinner? usually installed in your wall). If you want to do it mechanically, you could experiment with pullys and belts or gears and a chain. One thing though. If you reduce the speed mechanically (Gears or pullys etc) You'll have more torque at the output.


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## drzeus (Jun 25, 2011)

Niblique, thanx, interesting idea.
I didn't realize that brush motors could be controlled like that.
So I can run 6 volt DC thru the AC dimmer to the motor?
Would it be possible to use a smaller potentiometer to do the same thing?
And I assume that using this method decreases rpms as well as torque? (whereas the mechanical method reduces rpms yet increases torque).
I appreciate you time...
DrZeus


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## Joemes (Sep 13, 2010)

Use a potentiometer to change the speed of the motor, not an AC dimmer. This will solution will still impact torque. If you want to do anything with a load, use a gear assembly


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## Wildcat (Nov 3, 2007)

Instead of gear reduction just use a couple of pulleys and a belt. They can be had fairly cheap at Harbor Freight. For gear reduction try an R/C or model shop. There are small planetary gear sets that you can get but they tend to be a bit more pricey.


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## Allen H (Feb 13, 2010)

http://servocity.com/html/gears___sprockets.html


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## heresjohnny (Feb 15, 2006)

I have come to the conclusion that my time is worth money, and as much as I like to save a little money and reuse what I have I would simply buy the low RPM motors instead of rigging somthing up. AC Vent motors are only a few bucks (http://www.surpluscenter.com/item.asp?item=5-1587&catname=), deer motors around 8 if you buy them instead of finding them curbside. Reduction gear or pully rigs are likely to cost you more than just buying the vent motors. Just a thought, good luck.


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## corey872 (Jan 10, 2010)

Well, it's a 3-6 VDC motor, 119 g-cm torque @ 15,000 rpm (~0.025hp) about 1" in diameter.

IMHO, belts, pulleys, sprockets etc are mostly going to be out. The small end will be spinning at 15K rpm which is crazy for a belt. You might be able to do a worm gear drive, but that will need a pretty precise arrangement, too. Any type of gear reduction is going to eat into that 0.025hp pretty quick, too. Might be possible to find some pre-built gear train, but again, that would be hit or miss, too.

You can try a PWM speed controller - I don't know if a regular light dimmer would work at 6VDC or not? - my guess is not without some hacking. The down side is a PWM controller is probably going to be ~25 bucks, so that's going to eat into the 'free' motor budget pretty quick.

http://www.electronickits.com/kit/complete/motor/ck1400.htm

Personally, I don't know what I do haunt-wise with them. Economically, you'd almost have to use it as is - any speed control is going to far exceed the cost of just buying a slower motor of the same power. Maybe a 'micro' coffin jumper which pops up 15,000 times a minute!? Or sling a weight off the shaft to make some kind of vibrating-buzzing thing. Otherwise, I'd probably pop them up on ebay (assuming that works with any company rules for giving stuff away) then use that money to buy an actual motor I need.


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## drzeus (Jun 25, 2011)

Thanx All !

I was kinda thinkin these things are probably useless.
They are used in a device that sprays water via an impeller in surgical procedures (they are *not* in contact with bodily fluids):xbones:.
I doubt that they worth much (given their limited uses) even thru ebay, so I'll probably just hold on to them in case a need for a 15000 rpm motor happens my way. Can't imagine what that might be and its prob not worth investing in additional mechanics to make em work to my needs.
If anyone thinks they might have a use for a few of them, I'll send em at you at at shipping cost. Just pm me.


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## fritz42_male (May 5, 2009)

Some kind of vibrate effect?


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## niblique71 (Dec 2, 2009)

How about a fan for a firepit effect?? I'd be the resistance of a small fan blade would slow the motor down by about 1/3rd or more. You could also have axworthy's traveling at 200mph.


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