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Unread 24-05-2013, 01:58
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Re: Mecanum vs. Swerve Drive

Quote:
Originally Posted by LeelandS View Post
The only reason I can see not picking Mecanum for a third robot is if the team is trying to push with them. If a team builds a robot on Mecanum wheels and is pushing as part of their strategy, then I really wouldn't want them for a third robot.
How often are you picking a third robot with the intention of running an identical strategy to the one they ran in quals? Yes, sometimes it's similar, but there's a lot to be said for flexibility.

The thing is, mecanum isn't only worse than tank drive at pushing. More importantly, it doesn't resist being pushed very much. For a lot of defensive roles (including most of the "creative driving" roles you allude to in your post), if the defender can just be plowed through, the strategy doesn't work.

Here's an example situation. We had two decent choices left for the sixteenth pick at WPI. (The rest had <4 CIM drives, <100% powered wheels, or were not consistent at anything we needed) One was a mecanum drive robot with a full court passer (no scoring) that, while unreliable, could really increase disc throughput for our ground loading partner. The other option was a shifting tank drive with a 10 point hanger and a smart drive team. Yes, we could gamble and pick the unreliable mecanum shooter... but if they jam, what do they do? They can get in the way, but not enough to make much of a real difference in the final score. The ten point hanger could play any kind of defense needed - man to man, line defense, cover-the-disc defense.

Neither of these teams were running the strategy we wanted from them for most of Friday. One was a lot more versatile than the other despite having way less going on simply because they could resist being pushed and push well.

I won't go so far as to say I will never select a robot with mecanum wheels - but it will be despite their presence on the robot, not because of it. I've even seen mecanums play decent defense - it's just that the wheels are no help at all.

(by the way, despite my Mecanum Hater reputation here, I do think 2013 was an *okay* year for mecanum, and teams like 1100, 4134, 3824 played to its strengths)
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