Help me choose DIY motor type for my project

[neazoi]

Hi, I am working on a project where a small 3cm lightweight disc (Like a coin made out of carton) has to be rotated in speeds achieved by small toy DC motors. The only load to the motor that will spin this, will be this disc. Other requirements are low noise operation and high durability as much as possible
I am trying to DIY this motor for this project with the minimum motor parts required to build it.
Lathe and 3d printer is available, but the motor must fulfill these basic requirements and be composed of as low parts count as possible.

I have seen some PCB-printed coils, brushless DC motors projects on the internet. But I wonder if there is some other "motor" technology that can support this purpose.
For this I would like to think outside of the box, for example bearing-free motors (if magnetic "bearings" can be made easy to implement at this small scale.)

Any thoughts would be appreciated.

 

[KlausST]

Hi,

look for "hdd motor".

Klaus

 

[betwixt]

That's the first thing that came to my mind too. If this is a 'one off', get hold of a broken hard disc drive and salvage the motor. You will need to provide some drive signals to it but they are brushless, silent and about the right size.

Brian.

 

[BradtheRad]

Youtube has a variety of videos about making simple motors. Usually contains a battery and coil of wire. Other components might include a magnet, or reed switch, or transistor, or custom-shaped wire.

For your purpose a practical type is the 'kick' motor often found in the desktop 'perpetual pendulum' or 'jumping dolphins'. The swinging piece contains a magnet. A small coil in the base detects the approach of the magnet, turning on a transistor briefly which sends a current burst to a larger coil. This attracts the magnet, giving it a kick which maintains action.