Hey guys. My dad has recently come to love astronomy, and was especially interested when we viewed Jupiter throught our telescope. So for Christmas i was thinking of making him a 3D printer orrery. But im not sure where to begin. The earth (tilt and actuall rotaion) must be relatively accurate and with a motor ill choose real time or x10 or x100 the acctual time. I dont need all the planets (in fact i was going to do just a simple 1 of the inner planets minuse mars, and make it more detailed.) I just dont know how to get the gear scaling and such. Do you have any clues? This may have to be a easter gift b/c i imagine it will take awhile.
Thanks