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Unread 12-04-2010, 18:44
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Re: Mecanum or Swerve?

Quote:
Originally Posted by buildmaster5000 View Post
During the offseason this year, my team has discussed developing swerve drive, but after seeing a number of teams use mecanum with great sucess, I am torn between the two. Mecanum seems simpler and lighter, while swerve seems to give better control and more pushing power/resistance to being pushed. What are the experiences of the rest of the FRC world?
Here's my thoughts on the matter. Full disclosure being that I have yet to assemble a swerve drive in anything other than concept sketches, and my mecanum experience is also somewhat limited.

Mecanum drives are overrated, heavily. Often, people decide that they need the ability to strafe, or they decide "maneuverability" is important, so they jump to the conclusion that they should build a mecanum drive. Mecanum drive is a very specific tradeoff. You exchange drive efficiency, resistance to defense, and a bit of speed for strafing. If teams spent more time prototyping bases to determine how well a 6WD does what they aim for, and how much better a mecanum does the same job, I imagine there would be a few less mecanums around. Well driven mecanum robots have seen success in FRC, though, especially this year. 2008 had several, this year there's teams like 190, 230, 188 rocking the mecanum.

Swerve takes away some of the disadvantages of mecanum, while adding extreme complexity in design, build, and driving. Extensive preseason testing should be done with a swerve base before most teams consider the option of building one. From what little experience I have, it's a completely different ball game.

So basically, The question shouldn't be "mecanum or swerve", it should be "what traits of a drivetrain are most important this year?", and you should pick based on what is most important.

Extensive prototyping will always help you make more informed decisions on any part of the robot, including drivetrains. I would encourage any team considering anything new to do it!

Quote:
Originally Posted by Tom Line View Post
No - at least not by our scouting methods. Mecanum robots are immediately removed from our defensive pic list, as are robots with slick wheels / omni wheels. A decently geared robot with traction wheels will have no problem moving a robot with slick/omni or mechanum out of their way and scoring.

Mechanum are a neat idea (as are omni wheels), but once you bring robot to robot contact into the equation, I'd much rather have robots with traction that won't get pushed out of the way easily.
A question: Do you remove half and half teams from the list (2 traction 2 omni)? Personally I rate them lower but not completely off.

(I also generally avoid mecanums with any pick, personal preference, but there are exceptions to every rule)
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Last edited by Chris is me : 12-04-2010 at 18:47.