Mecanum or Swerve?

[big1boom]

This year we built both drive systems.

During the build season we manufactured a coaxial swerve very similar to our drivetrain in 2009. This took most of the build season, and used up a significant amount of weight. (final robot weight of 120.0lbs) We had many problems with this drive at midwest due to major design flaws that would have been caught with preseason testing.

After Midwest, we took a step back to look at the options we had for 10000 lakes. Turns out, since the withholding allowance was upped to 65 pounds, we built an entirely new robot in 5 days. In those 5 days, we managed to build a fully functioning mecanum robot that had more functionality that out build season robot. We were actually able to get the entire robot built and wired in 3.5 days, with the rest devoted to driver practice and programming. With this 5 day build season we managed to built the most reliable robot our team has ever built.


So, now onto the pro's and con's
SWERVE
PRO:
Able to direct 100% of the force into the direction of travel
Not able to be pushed sideways

CON:
Very difficult to design
Multiple points of failure
Requires high quality sensor feedback
Heavy
Time intensive

MECANUM
PRO:
Very simple build
Reliable
Easy to program
Doesn't require sensors

CON:
Can be pushed easily
Not able to put 100% of force into any direction.

For an offseason project, I would say go ahead and try to build a functional swerve. It will be a great learning opportunity.

For build season though, I would recommend against doing a swerve without fairly successful offseason prototyping.


If you have any questions about either system, or about the specific failures we discovered, go ahead and ask.

EDIT: Woah this post got long quickly