I'm old and crufty and only work on Battlebots now, but came across this super cool lift mechanism on reddit.
https://www.youtube.com/watch?v=oIuAAN0FbO8
It consists of a flat (in z) toothed spiral section locking together flat vertical helical sections with tabs, sort of in a locked version of that thing everyone used to do by rolling up a piece of paper and then pulling the inside loop one direction and the outside loop the other direction. The highlights of this design that make it better than say, a scissor lift are:
- Constant torque throughout travel range
- Final z height only proportional to starting x,y dimensions, so you can build this even in a super short bot
- Made almost entirely out of low(ish)-precision sheet metal
- Powered descent
- Passive holding capability
- Hollow, for passing game elements or wires through internally
- Isotropically stable - it's rotationally symmetric about the z-axis
I'd love to see someone prototype this during the off-season.