Mecanum vs. Tank Drive?

[svince]

Our team is currently trying to decide between using a mecanum drive and a basic tank drive from the KOP in order to effectively make a cycle for placing gears. Would mecanum be a viable alternative because of the precision boost, or would tank style overpower us in our runs across the field to the point where it isn't worth the change in style?

[euhlmann]

Mecanum
Pros: precise maneuvering
Cons: requires precise robot mass distribution in order to work. Also harder to program

Tank
Pros: easy to build
Cons: go up to feeder station. You're not aligned. Drive back and turn. Go up again. Still not aligned. Drive back and turn again...

[RoboChair]

Tank.

[AndyBare]

A tank drive will give you the ability to literally push your way across a field and hold your ground if you need to. Mecanum is a really good drive system if there's a reason. The field this year is flat, making mecanum a viable drive system to pursue. With limited visibility though, there is a possibility of you getting into situations such as being pushed around (perhaps while on the way to get fuel or gears), and not even recognizing what's going on. 2014 was a strong year for mecanums because the field was flat and clear. 2015 was a good year because there was no defense. This year, on the other hand, I'm not so sure. My vote is for tank.

[Tom Bottiglieri]

[Lord Basket]

The biggest downside by far to mecanum drives are that they can and will get pushed by everyone. In a game like Steamworks where there's an open field which most robots will regularly have to traverse, and where teams without functioning devices have nothing to do other than play defense, that one downside overshadows any and all minor advantages that mecanum drives have.

[GeeTwo]

Originally Posted by euhlmann

Mecanum
...
Cons: requires precise robot mass distribution in order to work. Also harder to program

Not really, on either. In 2013 we did mecanum. Using the canned mecanum drive class, it was no more difficult than a four motor tank system. (OK, an extra joystick axis). We ran it on our prototype robot, "woody", which had at least 4x the weight on one corner wheel than the opposite, but within a half hour of driving practice, drivers had learned to compensate so well that they weren't doing it consciously.

Actually, woody was the only robot we have ever built that I have over an hour of stick time on, due to a demo I did at work. All I recall was having to account for a slight pull to one side.

[ldsedam]

I would strongly recommend not using mecanum in any game where defense will have the potential to have an impact. The ability for a robot to be completely shut down by defense with little effort is a huge drawback. There is a reason why there has never been a mecanum drive on Einstein (Except 2015).

[chandrew]

Do you have experience building a mecanum drive? If not, I would definitely build the KOP chassis.
The clear field is great for a mecanum, however you want it done quickly so your drivers can practice driving with defense.

[Matt_Boehm_329]

I think it is easier to do well with Tank, but there is more potential in Mecanum. I also feel that most of what Mecanum can do, Swerve can do better (except module complexity).

[ns3517]

I would say tank because the cons of mecanum out weigh the benefits

[sonichammer7476]

It all depends on what strategy you are going to go for of course, but if you are going to play any defense or fight for balls in the neutral zone, I highly recommend tank over mecanum. 99% of the time, you will get tossed around like a rag doll when facing non-mecanum robots. No traction. But as one user suggested earlier, if you are very familiar with mecanum and not familiar at all with tank, or your driver is skilled enough to handle the challenges of mecanums in this game, then go with mecanum. Otherwise, I say tank.

[Type]

As it looks like most people, I would recommend tank. Using the KoP, it is very simple to do and does't really take much thinking or programming to do. Mecanum from my understanding isn't overly complex but it takes more work. A downside to Mecanum is that it can't really hold it's ground that well, and you could be pushed a lot. A tank drive may not maneuver as sharp or nice but with the defense ability this year, I would highly not recommend mecanum, but that's for the strategy my team wants. My team did mecanum in 2015, but we also didn't have robot-to-robot contact.

[MrForbes]

I think a small 6 wheel tank drive robot, in the hands of a well practiced driver, will be able to do amazing things.....

[niklas674]

Tank.