Just built a useful sander with a dc motor. The motor i got from a toy car and works great on 3.7 V battery. It can sand,sharpen,shape what you can't do with your hand on a sandpaper. it's not for heavy work though

Step 1: Uses

• Sands woods, rusty metals etc

• Straighten wood edges effectively

• Sharpens scissors,knives,blade etc

• It is useful for wood craft works. not for heavy works, the motor might fry lol

Step 2: Tools I Used

• DC motor

• Sandpaper

• A little piece of wood

• PVC Pipe (to use as motor handle)

• Handsaw

• Battery

Step 3: The Making

in these pictures, you can see how effectively it cleared rust or dirt from this aluminium. and you can see few small push buttons i made of wood

I got the motor from toy car. cut a small, half inch piece of wood, then shaped it to round with sandpaper, roughly, the size of a pencil

Then i bored a very small hole in it for the motor shaft, then stuck the motor shaft into it. I had to hit on top of the wood with little force to fix the shaft in wood in good hard position.

Then i glued a bit sandpaper around the wood. then put it and fixed tightly inside a PVC pipe to be used as a handle. Added a switch, battery and powered it!

Amazing, it's the cheapest yet, very useful sander you can ever make., after alot of using, u will need to replace sandpaper with new one.

It sands rust from metals too, effectively. And straightens wood edges. the motor not powerful enough to sand big wood. Just for edge sanding, metal cleaning, blade sharpening, and very useful for small wood craft.

If you can get a bigger motor, that runs on 12V, that would be more powerful and more effective. or you could power this motor with 12V. i haven't tried it, but the bigger the motor, the better sanding.