This is a mechanical clock that can help you explain time and clocks to kids. Everything is held together with #6 flat head sheet metal screws. 5x 1/2" long 1x 1.25" long https://youtu.be/VIQvrWtfXWE The numbers are raised. You can pause a print at a specific layer height in your slicer. Then you can change the material in your printer, and un-pause it. I let the printer do one layer of the numbers (and border) in blue, and then switched to green. This guy explains it well. https://youtu.be/pEbnix5wZP4 Inspired by: https://www.thingiverse.com/thing:1261900 https://www.thingiverse.com/thing:3011686