cycloide gears: additional parameter (head, fillets), + check geometry

[looooo]

There are not that many documents about cyloide gears, and I am not quite sure if the geometry is right.

• [x] head parameter
• [ ] head fillet
• [ ] foot fillet

[iplayfast]

No it's not right. This source (found online from http://www.zincland.com/hypocycloid should give you a leg up ) hypocycloid.zip also check https://github.com/dsuarezv/GearSolver

[looooo]

@iplayfast the cycloid gear in freecad.gears is another type which can be found here: https://en.wikipedia.org/wiki/Cycloid_gear

head and root fillet were added so I close this issue.