pic: Inverted CIM 2-Speed Gearbox

[asid61]

Originally Posted by Andy Brockway

You could eliminate those idlers by making your own gear sets. A quick search in the white papers using my name or "2005 716" will show a similar gearbox that we have been using off and on since 2005. The 12 tooth intermediate low gear has never been a problem for wear. This gearbox can be made on manual machines. One change is the that we use the stock CIM gear instead of the fancy tapered thread version in the plans.

As a student machinist for my team, I would recommend against making gears if you can avoid it at all. Indexing and cutting 2-3 times per tooth takes a very long time, not to mention all the work of taking a vise off the table for an indexing head or rotary table and centering everything. If you have the resources, go for it, but personally I can think of few situations where you would really want to do that (a 26t or 16t gear being those few situations ). I've designed swerve drives that can be manually machined, but not ones that you would really want to.
Buying spur gear stock or something similar would be good for making many custom gears.