Both of these are Thingiverse.com files.
The Math Gears is 18+ hour printing of 8 files. It works really neat and Princess Lilli the Bean of Candyland loves it. She was explaining ratios and relationships for probably close to two hours with me. I like the fact the when a rubber band breaks you can replace it without taking the Math Gears apart.
I just wish the axle trolleys for the gears had a little more meat underneath so that you could hold them with your fingertip a bit easier while changing gears.
Math Gear(s) by SSW
The Watch Escapement Desk Toy is a 20 file, 23-piece print, there are four prints of the base pieces. Print time exceeds 50 hours and if you print it, make sure you have the surface you want down or up. And it works pretty well considering that it is all PLA filament. I had to remove about 0.25” from the upper tine on the fork to get it to work, the hair spring simply does not have the power to pull the fork off the tooth at full length.
The Bean and I had a lot of fun learning how this works, and removing the fork and watching it free spool all that potential energy into unrestrained kinetic energy. The next day, showing it to my daughter and son-in-law, I broke the main spring – another 5 hours of 43 minutes of printing.
Watch Escapement Desk Toy by LarkysPrints
Note: If you go for this one, find the print modified to Imperial or U.S. Standard / fractional. The metric hardware exceeded $20. One bolt comparison between metric and Imperial was $0.79 to $0.19. M4 flat washers at $0.29 each.