[artdutra04]

Is there any particular reason why you chose to do the reduction in three stages?

If you are looking to build a custom transmission with an end ratio of about 10:1, you can use COTS gears from AndyMark with only two stages using a 50:14 (3.571:1) reduction in the first stage and a 40:14 (2.857:1) reduction in the second stage, for an overall reduction of 10.202:1. And if you have access to a milling machine or lathe, it isn't very difficult to lighten these gears with pockets and/or holes drilled through them.