[Peter Matteson]

Shifting is very useful. It allows you to quickly traverse the field and still push, pull or climb. I think the design of the game dictates how much you use it though.

I think teaching the students by designing and building the transmissions is a great idea. I think the knowledge gained is invaluble. However just to be that guy and make sure you know what your getting into I want to let you know some of my experience.

You will spend more money to make them than AndyMark's costs. Just know that right off the bat it has been discussed in many threads here at CD.

Plan out your gear meshing carefully. There are a lot of good white papers and threads to search here about suggest DPs for dog shift vs direct meshing transmissions.

If you use dogs to shift, unless you have REALLY good CNC programers and machines, just buy them from AndyMark. Trust me on this, it took two years of trying before we made the switch.

I suggest trying to work out a servo shifting mechanism as part of the project. The weight payoff should be worth it.

Pete