Electronics 2000

hi guys, im trying to design something and am in need of some help. bassically its a pin that needs to be motorized to go up when a button is pressed and when let go it needs to fall back to its original possition maybe via a weight or something. or if anyone has a better design than that would be appreciated.
cheers to anyone who reply's your name will be mentioned on the design.

I think you can make some gears and add tracks on the pin, so when the motor is activated, the pin is brought upwards. but you'd need to like add some sensor (or perhaps just like some connector thing) to check when the pin is at max.. but of course, this would make it jump as when brought to the max, it would fall down again then get into the connector and be brought up again directly, unless the button is depressed.

How much movement is needed? If it's only a small amount perhaps a soleniod would do the trick.

Dear Sir,
A Rack & Gear OR Worm & Gear arrangement may be tried for up-down movement. 2 Nos of microswitches be mounted in series with the motor supply could be used to stop the motor at the required movement stops.
Jitu