Tiny Planetary Gears Set High-Speed Adapters

First printed this timeless project a decade ago on my first 3D printer, an 8-bit homebrew RepRap running Marlin 1.x. Decided to revisit the project to see the impact of updated slicers & high-speed 3D printers on making the project.

The remixed items are a modified hex tool bit with a rounded shoulder better suited to high-speed rotation and a hex adapter for the tool bit that is designed to screw to the mandrel from a high-speed rotary tool cutoff wheel. Also included updated six-stage (87mm), seven-stage (99mm) and eight-stage (111mm) rods generated with the Openscad script. The zip archive attached to the remix includes the original three libraries updated to remove the deprecation warnings experienced when used with later versions of Openscad.

Successful printing of the longer bolts required printing them one-at-a-time with a 10mm brim, .1mm layers, 3 lines and no infill. This gave perfect results with fine threads and a strong rod when done in PLA+.

I built six (4096:1), seven (16384:1) and eight stage (65535:1) versions which printed six times faster than my original printer, even at a .1mm layer height vs. the .25mm of my original print and the resulting part fit was perfect.

When chucked in a rotary tool running at ~5000rpm, the following times were recorded for one complete revolution of the final stage:

Six stage: ~51 seconds
Seven stage: ~205 seconds
Eight stage: ~815 seconds

Going to experiment with higher speeds to search for the physical limits of the build, but it is so smooth and friction-free, I think there's a lot more in there.

Over a decade later, this remains a classic design!