Gear Reduction Fidget Toy

This gear reduction fidget toy is composed of eight 2 to 1 gears giving an overall 128 to 1 reduction. It's fun to play with and a great tool for teaching basic gear ratios. There are two print profiles: 1) a single color version and 2) a version with two colors on the gears to provide better visualization of the spinning rate differences (AMS required).

Start assembly by placing the first gear (small gear side down) onto the post with the well at the bottom. The well should hide most of the small section of this first gear. Place subsequent gears (all small gear side down) on alternating posts until all eight are placed. Secure the top with the two printed nuts using a penny or dime to tighten. Just tighten until snug - don't over tighten since they are just plastic threads.

While it takes quite a bit of force, I can turn the bottom most gear as it comes off the printer. If needed, you can light sand/steel wool the posts and/or add light lubricant to the posts to further improve smoothness.

If you like the model, please consider giving me a boost, or join my commercial membership program if you like to sell them.

Enjoy!