Hi-ratio evoloid planetary gear

thingiverse

One lazy afternoon I found a [German article](https://www.konstruktionspraxis.vogel.de/ein-baukasten-fuer-evoloid-planetengetriebe-sorgt-fuer-hoehere-untersetzungen-a-822596/) about a recently patented planetary gear system design allowing for hi-ratio translations 24:1, 18:1 and 12:1 with 3 planet gears ([patent description](https://depatisnet.dpma.de/DepatisNet/depatisnet?action=pdf&docid=DE102018107021A1&xxxfull=1)). This is extraordinary, because up to now 3-planet PGs were known to be restricted to reductions up to a ratio of 9. Being excited about the new possiblities such a design brings I immediately started to model it. The PG's design is quite tricky, as it depends on (positive and negative) profile shifting and helical gearing and employs a sun gear with only one tooth. Nevertheless my OpenSCAD code is suprisingly simple. More or less a some-liner, if all the stuff needed for mounting, axes, carrier and so on is omitted. Ok, under the hood it makes heavy use of my good old *gears.scad* library which already has built-in support for profile shifted gears - afaik the only lib in the net that addresses this feature. Please follow the link to my introductionary post [Cut your own gears with profile shift](https://www.thingiverse.com/thing:636119) if you are interested, how the lib works, how its designed, and how its used. I'm curious about your makes ...