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| View Poll Results: Swerve or Mecanum? Which does your team prefer? | |||
| Mecanum |
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26 | 24.53% |
| Swerve |
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49 | 46.23% |
| Neither, they are too complex and 4wd or 6wd will do the job |
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31 | 29.25% |
| Voters: 106. You may not vote on this poll | |||
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#61
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Re: Mecanum or Swerve?
The closest we've come to swerve was last year when our rear wheels were mounted on a small powered turret.
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#62
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Re: Mecanum or Swerve?
Quote:
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#63
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Re: Mecanum or Swerve?
Quote:
Just because your team won their first regional with a swerve design, doesn't mean that it's a good system. There are way to many variables that also have just as major effect on your regional win. The quality of drivers, your opponents, other mechanisms on your robot, the game itself, luck. There is simply too much room for other explanations. That said, I've very little interest in swerve or mecanum drives. Sure, they're cool to prototype, but unless a team has many years of experience driving one (read: practicing with a swerve bot in the off-season), has the machine shop and hands to build it near perfectly, the coders to ensure it's working flawlessly, the pit crew to ensure it's maintained constantly, and a host of other things, I just don't see them as that great an asset. Sure the occasional team like 111 or 71 will make swerves work, but honestly, is it really worth the upkeep? Some may say yes. I say go with what's solid, can be easily maintained, can be easily adapted, and doesn't require two joysticks to control. And that, is a 4 wheel, 6 wheel, or 8 wheel drive. Let the creativeness show in how you play the rest of the game with your manipulator. |
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#64
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Re: Mecanum or Swerve?
Quote:
There is another valid point of view however, a point of view which puts less emphasis on the "game" and puts more focus on learning. There is so much math and physics and engineering to be learned and so much creativeness and discovery can result from striving to understand and build a swerve or mecanum drive. Torques and force vectors, vector addition, trigonometry, bevel gears, software algorithms (closed-loop position control for the steering, closed-loop speed control for the wheels, how to properly adjust each of the wheel speeds - and directions for swerve - to reduce scubbing and maximize efficiency), the list goes on and on. So even if you don't win the game, you may come out ahead :-) ~ |
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#65
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Re: Mecanum or Swerve?
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I did the math last year about swerve percentages, but there have been 4 teams to win the championships with a swerve. (111 twice). In total 42 teams have won nationals. That's 9 percent to win with swerve. People often question "more teams compete with drivetrains other than swerve, so the odds are swerve won't win as much" but in reality, the best teams win, or at least really good teams do. If swerve teams consistently dominated skid teams, it would reflect in the stats, and they don't reflect that. I'm not saying swerve is bad, I'm just suggesting that the advantages it appears it have on paper aren't quite the same as on the field. Last edited by sgreco : 16-04-2010 at 19:16. |
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#66
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Re: Mecanum or Swerve?
Quote:
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Just to share a bit of a conversation I was having the other day, the problem with swerve drives is that the wheels are never in the direction you want to go. There is a slight delay. If the driver is aware of this and does not try to correct for it you will be fine. Otherwise you end up going in a bit of a circle. It takes some getting used to. Not a downside just a fact. If you decide to go with a swerve drive robot you need to build a practice bot so your driver can get the hang of it. |
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#67
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Re: Mecanum or Swerve?
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#68
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Re: Mecanum or Swerve?
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Actually, in this case our swerve drive was the reason for our success. Our alliance had two strong offensive robots (230, 20) and we were the strong defensive robot in the opponent's home zone. Without a swerve drive, we would never have been able to defend two robots simultaneously by constantly strafing, out-maneuvering, and out-pushing them. |
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#69
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Re: Mecanum or Swerve?
Quote:
Is this true only for swerves with unlimited steering rotation, or is it also true for swerves with limited steering rotation? Quote:
~ |
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#70
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Re: Mecanum or Swerve?
For us, the reason we wanted to build a swerve drive is that we had trouble with our 6wd drop center wheel this year, so we wanted something that would offer more mobility without suffering in traction. We also had considered getting the 221 modules at the beginning of the year, but decided that our ONE programmer was going to be busy enough so we would wait for the offseason. I am personally more and more convinced that we should do swerve, and that we should be able to mount our modules on the bottom of our frame from this year after we take the kit wheel brackets off. It is interesting how different teams use swerve then never use it agian, but I agree with whoever said that driver practice, and lots of it, is how to get comfortable, and therefore good, with swerve.
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#71
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Re: Mecanum or Swerve?
I really like the swerve drives over mecanum drives.
I am working on a cad of an offseason swerve system right now. It should be posted soon. |
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#72
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Re: Mecanum or Swerve?
If you could PM me when its up, that would be great!! We have been stuck with the 221 modules because we lack the resources to design one ourselves
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#73
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Re: Mecanum or Swerve?
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I understand that Lone Star and Bayou are considered to be "easier" regionals but we controlled that competition from our very first match. At nationals we had some code and design issues that prevented us from success... We gave in to the temptation to fix something that was already working. But overall I love the mecanum drive train and watching one work is a beautiful demonstration of force vectors ![]() |
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#74
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Re: Mecanum or Swerve?
This year, we had a tank drive with 2 omni's in the back, so the robot would turn around its front (where the ball is), and we only used 2 cims. We could have added two more, but two seemed to be working fine; we could push well, and we could move around okay. We didn't end up adding two more because of the added weight (which would slow our hanging down).
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