Hi CD,
After watching the latest "Lunch with Andy", I saw that a Canadian team had done some cool testing of different drivetrains. Turns out, they actually did their own Robot in 3 Days competition (give or take a few hours). Their testing of different drives, as well as their mechanisms, are extremely well done, and there are great subtitles for those who don't speak French.
Hopefully I'm not stealing their thunder posting to CD.
https://www.youtube.com/channel/UCFf..._-nCEkg/videos