Gear Chain Fidget 28-1 Reduction

When I was making the gear chain for my excavator, I found it very fun to play with. I decided to make a fidget version of a gear chain. When you spin the small gear on the top once, the gear on the opposite end will spin 28 times. It's a very satisfying feeling!

Warning,

I just printed another one on a different printer and found that the printer left a little seam line in the middle of the gears that was increasing the friction significantly. So I found it very beneficial to take a 15/64 drill bit and just ream out and clean out the hole in each of the gears. Also, "Siderbright"on Thingiverse mentioned adding a little lubricant can be beneficial.

I highly recommend using 120-grit sandpaper to smooth off the textured side of the gears to decrease potential friction in the movement of your gears.
 

The gears have small indents cut into them to indicate their location in the housing.

I have included an optional idler gear, which is more kid-friendly, as it is disengaged from the gear chain and thus easier to spin. It can replace the largest, high-speed gear. 

Also, if you plan to give it to smaller children, you can feel free to glue the two halves together when you assemble it, making sure not to let any glue touch the gears but the unit should hold together fairly well without glue, which also allows you to disassemble it if you're having issues and want to sand the gears some more.