Rotary display as supposed to LED

[Guest kdfossum]

Quick question. In the AFDS and other parts of glare shield on real 747s and other jets, the altimeter etc. is displayed with rotary numbers as supposed to LED. I've figured out that I rather want to use the old rotary numbers. Is this possible? Has anyone else done it?Can parts from e.g tape machines be converted for this use? If so, how?Any feedback appreciated.Regards,Kevin

[Guest MikePowell]

Kevin,I think what you're referring to is a drum altimeter. I don't know of anyone yet who has built a simulated one, but they show up every so often of Ebay. One approach might be to buy a dead one and stuff a stepping motor in it. Another approach is to use parts from an odometer. Combine that with a 400 step per revolution stepping motor for driving the single pointer. Electronics Goldmine is an online surplus store that carries stepping motors. You'll need a few random gears to tie the mechanical stuff together. Try ServoLink for that. They carry some nice 48 pitch Delrin spur gears. Of course, you'll need to throw a in a micro controller for good measure. A PIC16F628 would be a good choice. They're cheap, easy to program, and have a serial port for easy interfacing.Mikewww.mikesflightdeck.com