So, wifey has put in a request. She wants to make a clockwork windup key thing which she can wear as part of a costume. So, imagine her done up as a doll, with this big key sticking out of her back, ticking away like a windup mechanism. She can make the dress and the key - I need to provide the mechanism. I haven't been able to simply find a mechanism on eBay or Aliexpress, so it looks like I'll have to make one. My thoughts go to Arduino. But do I want to use a stepper motor or a servo? It needs to:: - rotate 360 degrees continuously (the servos I have are 180 degrees only) - tick along in visible increments, not just smoothly rotate - drive a fairly light but large key - be fairly low profile so it can be hidden in the back of a dress - be tolerant of some random giving it a wind Sooo.. from Googling I can't work out whether a servo or stepper motor or something else might be most suitable. Thoughts?