I've love to get my hands on this print and try it out - I may have to download it and try printing at the local makerspace, since I don't have 3d printer as of yet. I like that you're using these cheap, small motors. I've only played with them a briefly, but was impressed by their torque and low cost; I'm actually surprised you have to use more than 5 volts to get them to work. I modified mine to increase torque as per this video: https://www.youtube.com/watch?v=jHLyJbNgcDo
They seemed like they would be strong enough to move a fairly large mirror....
Good work, and thanks for sharing!