This isn’t my idea, but for a project (converting a dashboard in a Honda Civie 1998) I needed a strong servo motor. We tried an MG996R first. But that was way to weak. So why not use a Windshield wiper motor used in a car. They have a worm-gear mechanism, cost little and need no maintenance.
Next was something needed to measure the position. I saw a youtube film of someone glueing a potentiometer onto the shaft and using that as measurement. However potentiometers might wear out too soon until I found a very nice compact adjustable potentiometer (bourns 3382H-1-103).
These pots can rotate continuously. But only work for about a 300 degrees range.
I am using a simple ATTiny45 as a controller to compare the potmeter value to a set value. And that is all. I can get the 5V from the L298D board. I made a prototype board for testing purposes. So far it seems quite succesful.
On the Windshield wiper motor the shaft is replace with a stronger shaft with ball bearings making it very stable. If all goes well I should have a very nice version at the Amsterdam Maker Festival 30-May to 1st of June 2014.