Tiny Tiny Motors or Servos?

Apart from motors and servos what method are available for spinning a gear head between 2 positions.

I am looking to spin a small .5cm disc (very thin, very light) either made from metal or plastic. It needs to be able to turn to 2 positions only, say from 12 o-clock to 6 o-clock, so around 180 degrees but a 360 degree spin can be controlled via software.

The discs would be very small and would be grouped together so the motor or servo profile would have to be a maximum of 1 cm in diameter, a similar size to the small vibration motors used in pagers and mobile phones.

Does anyone know of or where i can find small motors like these that may already be used in another product or an alternative method of spinning a disc from 0 to 180 degrees (2 steps), i cannot seem to find anything suitable on a google search.

Any ideas welcome

This is the smallest servo I have seen:

What about this tiny stepper?
The listing says it's a 18 degree per step, which fits nicely with you 0 and 180 requirement.

That is small :slightly_smiling_face:

Thanks LarryD but i was thinking more along the lines of this size and profile:

Inside it is a small motor but do motors of this size exist that can actually spin something very thin and lightweight, even if the disc had a tiny magnet on top about 1/10th the size of the disc itself?

I do not want the disc to continuously spin around but rather spin from one position to the other

Is it possible to control the position of something like this:

Shpaget now those look very interesting, thanks. Can these be put close together without interfering with each other?

Great i found some with a plastic gear head attached, tiny things, you have to love japan.
I imagine these are used in cameras then as i found some tiny worm gear motors and screw rod types.


You could just use a solenoid with a cord wrapped around the axle of the disk. It would be lightening fast.

Is it possible to control the position of something like this:

That's a mobile phone vibra motor.
No, without gearing and feedback, it isn't possible to control the postition.

I hadn't thought about that KenF thanks but speed is not an issue here anyway and i dont think that would give me a reliable position.

Main priorities are size, reliability, power consumption and position feedback (which i think may be an issue for these micro stepper motors and the reason i first looked at servo's). I don't want the discs to be anywhere but position 1 or 2 (0 or 180 degrees), i may have to place something on the disk to stop to spinning past a certain point.

I have added hall effect sensors with small stepper motors before on another project to move the stepper to a home position on start up.

What other methods are there to get positional feedback from a stepper motor?

If only two positions are needed, a tiny bar magnet and a very small solenoid are all you need.

You can salvage a small, very low power solenoid containing hundreds, if not thousands, of turns of fine wire from a small digital clock motor. They usually have an iron core with a space for a rotor, so you might be able to use a large part of the clock mechanism.

Like this one, or the next:



Thanks jremington i like the idea and the power consumption could be much better than my micro steppers but i need to make these as small as possible and have them bunched together fairly tight (the micro steppers i just ordered are 6mm x 6.5mm) and also i would want a fair few of them.

Something like this is what i am after:

Imagine the grey area is a base/top and the red circles are the discs and each disc has a triangle (for example), i want to be able to move the triangle so it is either pointing to the top or pointing to the bottom. Speed isn't all that important.

Moving them to the up or down position and keeping them there without keeping current applied would be a great benefit too, which i think is possible with the motors as i can move to the position and switch off (i am assuming the bar magnet solenoid idea i would have to keep current applied constantly to hold one position)

The phone vibrator motor can be used with two mechanical stops at the required positions. Just drive it hard into the stops. If you need any more than 2 positions, then it gets more complex. The tiny steppers look ideal to me.

Yes, I don't see a problem with them being close to each other. I doubt their magnets are strong enough to affect the neighbors.

This is what first came to mind for me: