Drive Trains & All that they encompass

[ksafin]

Hello all.

I think most teams recognize that no robot is good without a decent drivetrain. We even had the mistake last year of working on our entire shooting and picking up mechanism only to find out 3 days from packing day that the robot was incapable of moving because the drivetrain was so horrendous.

I've read many threads about various drivetrains, I've done a good deal of research, but I would really like to spawn a comprehensive discussion about several aspects of drivetrains, what makes them good, when to use what, etc.

A few personal points I would like addressed:
(It's not vital that you address every single one, but these are some things I would love to hear answered for the benefit of knowing more about drivetrains as a whole)

1) What wheels do you prefer
1a) What kind of challenge/obstacle prompts a certain wheel choice
1b) What kind of wheel would you use if you had a low budget (aka can't afford $1,000+ on swerves)
1c) How do you personally choose what size wheel you prefer?

2) What do you make your drive train out of? (Base train, custom, 80/20, etc)

3) What gearboxes do you use for your motors, and why?
3a) Do you use shifters? Why?

4) What kind of wheel setup do you choose? (4 wheels, 6 w/ 2 dropped, etc etc)

5) How much time do you normally spend building your drivetrain?

6) Do you prefer to use belt or chain? Why?
6a) What would prompt using one over another?

7) Generally, long robot, wide robot, or it depends on the game?