Gear system types 101

[Elgin Clock]

Found this in an article of Machine design.
Looks like a start if you are trying to figure out what gear system to use for your drive or any application on your FIRST Robot.

http://www.motionsystemdesign.com/Content/Site011/Articles/11_01_1999/166334pdfpdf_00000008139.pdf

[Richard Wallace]

Nice find, good pictures. Thank you, Elgin. :)