More on Flip Face: Mechanism #4.
Here's my implementation of mechanism #4 as per the previous post. It works a treat!.
From the back you can see how the parts fit together. The pinion wheel, with face attached, is a ten tooth wheel, the rack gear is a section from a fifty toothed wheel. The mechanism as a whole, needs tidying up, with spare space being removed and parts aligned properly. I might re-do the face as well as it is beginning to freak me out!