Penalizing mecanum wheeled robots durring alliance selection.

[Justin Montois]

All other things being equal, we would most likely pick a non mecanum drive over a mecanum drive.

However, I think it's important to point out that rarely are all other things equal. Like anything else, design to play the game well and be consistently contribute to the alliance in a positive manner.

[magnets]

Originally Posted by Max Boord

They where this year.

Yeah, but they never touched the carpet

[pabeekm]

This year, the robot's drivetrain didn't matter to us nearly so much as how the robot was being driven. This was probably our biggest selection factor; I asked scouters specifically to note great or poor maneuvering (especially around defense). We even used our first pick as 2nd seed at North Carolina on a 44th seeded box bot, just because they drove very well. Likewise, plenty of drivers at champs proved that mecanum was no hinderance if utilized well.

Discriminating against robots for particular attributes should not be done if they can hold their own on the field, period. Unfortunately, teams with such attributes do have to prove themselves to overcome doubters, and even then, the tiniest of concerns might be enough for alliance captains to discredit them.... it's really unfortunate, but it happens, whether you're a mecanum bot, rookie team, or had no intake this year (cries in corner).

[Peyton Yeung]

When teams were scouting our robot it seemed like they were penalizing us for having mecanums even when we told them we were using 4 cims and 4 mini cims.

[indubitably]

8 motor mecanum isn't bad

[MARS_James]

Originally Posted by Peyton Yeung

When teams were scouting our robot it seemed like they were penalizing us for having mecanums even when we told them we were using 4 cims and 4 mini cims.

You have peaked my interest, was there any noticeable difference in performance in comparison to the traditional 4 motor? Specifically in terms of pushing power or resistance?

[Sam_Mills]

Originally Posted by Rypsnort

I have not personally been a part of selecting teams, but I have noticed that you have to have a strategy in your alliance that accommodates a mecanum drive bot. Mecanum is good for being evasive (if built and driven well) but is bad for being physical and getting in pushing matches. If you don't have a need for it don't pick it(mecanum drive).

Not to call you out specifically, but you mentioned something that is frequently spread around, and not quite true. Mecanum is often touted as being good for being evasive, but due to the fact it must be geared slower (for more torque) to strafe well, they typically can't outmaneuver a tank drive (this is especially true in the 6 CIM era). If you want an example of this, look to Ultimate Ascent;

There was a very small handful of robots able to complete 7 cycles, which was a task that required nearly no pushing, and all maneuverability. If mecanum wheels were more maneuverable, you would expect the best cyclers to be mecanum robots, but this was not the case. 118, 469, 610, 245, 868, 11, etc., were all tank drive robots.

Originally Posted by SeanFitz

I think it really comes down to how big your wheels are. In 2013 we bought big 8" diameter, 2" width wheels and were actually one of the better pushing robots out there (didn't get picked, but that was mainly because our shooter was awful). In contrast, we used 6" diameter, 1" width wheels in 2010 and got pushed all over the place.

"Pushing Power," is a function of coefficient of friction with the floor, robot weight, and torque. Wheels sizes (widths) can influence coefficient of friction, but tread material is typically a more important factor. Wheel diameter can also affect coefficient of friction by changing the size of the flat patch you have on the carpet, but this has a pretty minor effect. Torque is a function of your gear ratios and wheel diameter together, as well as the efficiency of your transmission, but you can gear for as much toque as you want, regardless of wheel size.

TL;DR: You can push with small wheels if you want to, just be aware of the variables at play.

[1493kd]

As a team that went with mecanum this year (as much as I did not want to) I can say that it was a factor in teams selecting us. At TVR we had teams tell us they would pick us if we switched to traction wheels. I believe we had a great bot design for the game but the mecanum just made us a bot that could get pushed all over ( esp by 2791). Needless to say we have switched them out for offseason events, Im looking forward to seeing the results.

[marshall]

Originally Posted by pabeekm

it's really unfortunate, but it happens, whether you're a mecanum bot, rookie team, or had no intake this year (cries in corner).

Wait, being fed by human player doesn't count as an intake?

[BrendanB]

Yes, if you have mecanum wheels it will lower you on my picklist. Especially for our third pick robot we try to avoid teams with mecanums because its very hard to play effective defense with mecanums. It is possible I have seen it done but most of the times these teams have a solid offensive strategy too meaning we wouldn't want them to play defense to begin with as we need them to score.

We have picked/accepted invitations from teams with mecanums more notably this year we allied twice with 58 and once with 126 both were very effective robots on the field with mecanums. If there were identical robots to them just with tank drives I would have rather gone with the tank drive.

You might call it "penalizing" but I see it as a weakness if the other alliance can push you around as much as they please.

[Chadfrom308]

Our mecanums this year were the best i've ever seen. We had 4 CIMs and 4 mini-CIMs.

We ended up pushing practically everyone. Yes, there are a few battles that we lost, but we just spun around them and continued. I was surprised by the amount of power that we could put down.

We pushed a whole bunch of 6 CIM 6/8 wheel drivetrains.

[Peyton Yeung]

Originally Posted by MARS_James

You have peaked my interest, was there any noticeable difference in performance in comparison to the traditional 4 motor? Specifically in terms of pushing power or resistance?

Well it definitely made for a heavy robot(~22 pounds in motors and motor controllers). It had quite a bit of torque but it was still hard keeping 6 wheel drives off us.

[Jared Russell]

Originally Posted by Chadfrom308

Our mecanums this year were the best i've ever seen. We had 4 CIMs and 4 mini-CIMs.

We ended up pushing practically everyone. Yes, there are a few battles that we lost, but we just spun around them and continued. I was surprised by the amount of power that we could put down.

We pushed a whole bunch of 6 CIM 6/8 wheel drivetrains.

Any videos of this?

[DampRobot]

Originally Posted by Jared Russell

Any videos of this?

Not quite the same thing, but reminds me of this thread.

[cadandcookies]

2220 has been picked by a certain MN team that has used mecanum for the last few years-- 2052 (who has also won three regionals in a row now).

However, frankly, they're the only team I've ever seen that was successful with mecanum-- and that's because a whole lot of driver practice (they're also the only mecanum bot I've seen that actually "runs circles" around others in terms of evasiveness), and just generally the great quality that they build into their robots.

It's all performance/quality based. I will admit that I tend to scrutinize mecanum more than tank, just because I've seen more subpar, problematic, or nonfunctional mecanum bots than "conventional" NWD bots.