# Small, Low Speed Prop Motor?



## austenandrews (Aug 22, 2010)

Here's my situation: I've designed a simple animated prop that operates via a single rotary cam. What I need is a motor to turn the cam at 1 rpm or slower. The props are small (about the size of a stuffed animal) and light (vacuum-formed plastic) and the movement is minimal, so the torque needn't be high. 

The problem is that I intend to make lots of them (a dozen or more) so the per-prop cost needs to be quite low (under $5-10 if possible) and the construction shouldn't be complex and high-precision (I'm no machinist). That means fancy electronics and expensive gearboxes are not practical. The small size of the props means the mechanism must be small. Also I need to place them arbitrarily around a yard-size space, so they can't be tethered to a computer or a power outlet.

Any ideas?


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## HomeyDaClown (Oct 3, 2009)

https://www.surpluscenter.com/item.asp?item=5-1587&catname=electric

You could mount a small pulley on the motor and use a large rubber band or vacuum cleaner belt to drive a larger pulley to get it down to 1 rpm. Or, direct drive a larger pulley with a rubber (toy) tire on the motor just like the old record players worked.


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## Denhaunt (Aug 18, 2006)

I just ordered 5 - thanks for the heads-up. I hope they have at least the same torque as a deer motor.


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## heresjohnny (Feb 15, 2006)

Denhaunt said:


> I just ordered 5 - thanks for the heads-up. I hope they have at least the same torque as a deer motor.


I use these in my ghosts, they do have a lot of tourque. In my experience they do not have as much tourque as the rein deer motors, but the rein deer motors are very strong. I already used the first 10 I ordered and I just ordered 10 more


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## austenandrews (Aug 22, 2010)

That looks perfect! I'm ordering some now. Many thanks.


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## SuperCreep31 (Nov 22, 2009)

those look sweet but question-how would i power these handy little guys? wiring or what?


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## heresjohnny (Feb 15, 2006)

12 volts DC, I use PC power supplys, you can also use 12v Wall-Warts.


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## austenandrews (Aug 22, 2010)

8 AA's should do the trick, I assume? Or a 12V A23?


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## hedg12 (Jul 6, 2008)

austenandrews said:


> 8 AA's should do the trick, I assume? Or a 12V A23?


You'd be much better off with D cells - AA's wouldn't last long. If your prop is light enough you could run the motor off of 3V (2 D cells) and get closer to the 1 rpm you're looking for.


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## austenandrews (Aug 22, 2010)

Good point about battery life, since I plan to turn them on and let them run (relatively) unattended all night. I'm fairly new to electrical work, so I wasn't sure you could just lower the voltage like that. Wouldn't that make the motor run hot? Or is that only if your load is high?


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## hedg12 (Jul 6, 2008)

Nope - DC motors don't much care about being under voltage. You're right abut the load though - don't load them too heavily. Just to test, I hooked one to 3.3V from a PC power supply a little while ago & it ran fine with a light load.


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## HomeyDaClown (Oct 3, 2009)

I would test the speed/load with 2 or 3 D batteries (3 or 4.5 volts).
I've made quick/cheap D battery holders with 1¼" PVC pipe, the inside 
diameter is just a little larger than the batteries.


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## mroct31 (Nov 10, 2007)

Whatever you use for power a PC power supply connector, the one that plugs into the motherboard cut across, so you have 2 connections fits perfect on these motors power tabs. As in the image, cut away "2" with wire and it makes a great adapter to hook into the motor.

[][][][][][][][][][][][][][]---[] 
[][][][][][][][][][][][][][]---[]


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## HomeyDaClown (Oct 3, 2009)

mroct31 said:


> Whatever you use for power a PC power supply connector, the one that plugs into the motherboard cut across, so you have 2 connections fits perfect on these motors power tabs. As in the image, cut away "2" with wire and it makes a great adapter to hook into the motor.


There's a whole thread on that motor connector topic here:

http://www.hauntforum.com/showthread.php?t=23360


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## hlmn (Aug 30, 2008)

those are great little motors


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## nixie (Sep 17, 2008)

Ok, I know nothing about motors, but curiosity is killing me here! What are you building?? It sounds interesting!


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## austenandrews (Aug 22, 2010)

Kodamas.






If I can figure it out. The motors work great but I'm realizing how little I know about actually constructing a simple machine...


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## nixie (Sep 17, 2008)

Oooh, I like them!! They're cute and creepy! Best of luck, I hope you get it all worked out! I would love to see a video of them in action!


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