Planetary gear set with square sun gear - GIF

[old kodger]

how about a really big one, and call it an anchor?

[marksbug]

or possiably it's for one of those sock knitting thingys...or braiding machine......IT A PRETZEL MAKER!!!

[old kodger]

Many years ago, the Royal Aircraft Establishment at Farnborough in England, set up a project for stuff like this for the apprentices, probably to stretch their imagination, after all Farnborough was(is) an experimental facility. One submission was a model bicycle with triangular wheels. True,it needed a special "road" (much like a rack), but it did work.
Aside from satisfying the project parameters, it was about as useful as tits on a bullfrog.

[marksbug]

just think about a wankel/mazda rotery engine....wtf? that cant work!!! and yet it works just fine..and can be expanded upon. just because something looks wonkey dont mean it's a donkey.

[hemmjo]

and it's used for what?

It is to drive an apprentice machinist crazy!!