Eccentric cycloidal Gears tutorial

Cycloidal Drive Gears demo in Fusion360 files included, This type of gear stands out because it allows a high reduction like the standard cycloidal gear, but the design process is much much simpler, just use the sketch and history to learn the process of making this kind of gear

there is a variation of this model with internal gear 

https://www.printables.com/model/819631-internal-cycloidal-gears-tutorial