Need a low RPm motor for scenery item

Antenociti · Post by **Antenociti** » Fri Aug 21, 2009 2:54 pm

I need a very slow motor or servo that can rotate a 30gram DNA double-helix "statue" on a piece of scenery....

it needs to be pretty small so that it can be hidden inside a low "hill", i have probably no more than 50mm height in which to hide it.

couldnt find anything obviously suitable in a google search... doesnt matter where i get it from, preferably <£10 as i would like about 3 of them... but if they turn out to be expensive then i can settle with just one.

I would imagine something like 10/12 RPm would be about the maximum.

the scenery is roughly 1/42nd scale.

Kylwell · Post by **Kylwell** » Fri Aug 21, 2009 3:57 pm

Something that slow will need to be geared and with that low height it might need to be a pancake motor. Take a look @ these, might be something you could use.

modelnutz · Post by **modelnutz** » Fri Aug 21, 2009 9:05 pm

my suggestion would be... buy a low cost RC servo.
You can modify them for constant rotation by modifying the large gear in the gear train.
Pull the servo apart ( just need to access the gear train ) remove and look at the underside of the gears.
One should have a small bar molded on. This is a dead stop.
Trim this bar off the gear...re-assemble then you can hook up a battrey to the center wire and either of the outer wires ( to determine rotation direction)
Or, you could just wire in directly to the motor...you don't need the circuit board any more.

This works quite well and it's fairly low in cost.