[Oblarg]

As previous leader of the 449 Drive Team for two years, I'd like to put in a few good words for mecanum.

First off, there is almost no power loss in forward/backward movement in a mecanum drive - the rollers do not move unless you are strafing. The fact that mecanum is "less powerful" is a common misconception - mecanum is *not* omni holonomic, and the only difference in power is the difference in coefficient of friction with the floor between the roller material and the material of your six wheel drive wheels. Mecanum's only real weakness with respect to being pushed is from the side, which in this game isn't all that important as the other robots are not allowed to interfere with your goal scoring. Last year during the DC regional we had some issues with ball manipulation that forced us to change our strategy during the quarterfinals to "go into the front zone and push the defensive bot out of the way," which we were able to do with no problems at all.

Secondly, strafing is *amazingly handy," especially in a game like this years in which staying lined up with a goal is crucial to success.

Thirdly, it is not particularly complex. One your team invests in writing/acquiring decent drive code, building a mecanum drive is as trivially easy as building a normal four wheel tank drive. Well, perhaps a wee bit more, as you need to have one gearbox per wheel.

Fourthly, mecanum is also fairly robust - we have lost rollers and drive belts and still been able to play the game fairly well, as even a mecanum missing the strafing capability can turn better than a standard 4wd. You really don't even have to adjust that much for it on the controls. We were able to traverse the bump last year as well as any other robot at the competition without mucking up our drive in the slightest.

And finally, I am amazed at how AndyMark's mecanum wheels have improved over the years. We had very few maintenance problems with our rollers last year, and the main issue we had (difficulty in adjusting the connection to each roller) seems to have been fixed on this years generation of 6'' mecanum wheels.