Learning and Understanding different drivetrains

[EricH]

Originally Posted by safiq10

Currently we are stuck on West coast drive... We are absolutely stumped on what benefits it gives and why we see some of the more elite teams using it?

It's a very balanced drivetrain.

For reference, a "true" WCD is 6 wheels, cantilevered outside of the frame, with the center wheel directly driven off the gearbox and the rest powered by belts or chains, with the center wheel dropped some fraction of an inch--oh, and it uses live axles. I'll be talking about the general 6WD drop-center (as opposed to a 6WD with corner omni wheels and the 6WD scrub turn), rather than a true WCD.

First, it's dirt simple. About the only thing simpler is a 4WD, and it's not that hard to swap it down to that. However, it has a shorter wheelbase, due to the dropped center wheels, so it turns much more smoothly than the "Mexican jumping bean" that I've heard the 4WDs compared to. If one or more of the wheels are directly driven, you just about can't lose half of your drivetrain in one mishap (or you'd have lost it anyway). It's easy to turn when you want it to turn, but not quite as easy as a corner-omni configuration.

The true WCD adds ease of maintenance--the wheels are easy to yank off when you want to swap 'em--but also adds complexity of machining (or increases the cost as you buy the parts).

As a note, the WCD has been in use for 10 years or more. It might not be as maneuverable as a swerve or mecanum, but it's pretty effective, and is likely to be sticking around another 10 years or more.