Penalizing mecanum wheeled robots durring alliance selection.

[Pat Fairbank]

Automatic DNP, unless there are too many mecanum bots for that to be possible.

It's not that mecanum wheels are inherently bad, just that 99% of the implementations we see are.

[TAlholm]

If the team drives the mecanum drivetrain well, I see no reason to leave them off the list.
Then again, I don't do any scouting.

[ChuckDickerson]

In my fantasy world I would dearly love to see Teh Chezy Pofs do mecanum just one year so they can show us all how we have been doing it wrong all this time and then maybe everyone else would stop the mecanum bashing and shut up about how mecanums are never on Einstein.

[DampRobot]

Originally Posted by ChuckDickerson

In my fantasy world I would dearly love to see Teh Chezy Pofs do mecanum just one year so they can show us all how we have been doing it wrong all this time and then maybe everyone else would stop the mecanum bashing and shut up about how mecanums are never on Einstein.

I think you'll see it when they decide that powdercoat looks kind of stupid, wires don't care if they're ziptied down or not, and that they should stop driver practice because it distracts from watching South Park.

[Chris is me]

Originally Posted by Max Boord

Over the years as mecanum drive robots increse in popularity its become incresingly common for teams that seed in the top 8 to penalize 1st round picks for having a mecanum drivetrain. So CD comunity, what does your team do when it comes to mecanum drive robots?

We're not penalizing anybody. We're picking robots that best complement our robot and the strategy we want to play in the elims.

In 2014, there was no place for a (pure) mecanum drive robot on our alliances. The ability to resist pushing was viewed by us as essential to forming a 3 assist cycle. Resisting pushing with traction allows for "wall" defense and also helps avoid being spun while shooting or ejecting. People argue about whether mecanum can push or not, but they're really missing the point - pushing resistance is where mecanum robots really struggle.

There were some robots at our events that were mecanum drive that played fairly well but without traction they just could not get into and hold position where they needed to be. Setting up truss shots or passes with them was just too difficult when they could be spun by defense. In spite of this, there was just one other robot on our list between our alliance's second pick and a mecanum drive robot at Finger Lakes.

In other years, the "cost" of a mecanum robot versus a traction robot varies. I feel it's worth noting that more often than not the best several teams at a regional are all tank drive. In this case the teams aren't being selected because they aren't mecanum, but because their robots are overall better than the mecanum robots are. In addition, in the somewhat rare event that the best teams at a regional include mecanum robots, these robots tend to have well driven and implemented mecanum drive systems.

To be quite frank, I think a lot of teams that aren't very good pick mecanum drive because they feel like the ability to strafe allows them to drive better with less practice. It seems more trivial to just gun the robot forward into a scoring zone, then strafe to where you actually wanted to be, than it is to drive in a smooth arc up to where you wanted to score. However, without plenty of drive practice, it doesn't matter what your wheels are, you're a lot less likely to be a first round pick at all.

In short, there's almost no situation where all other things equal, a mecanum drive is a net gain over a tank drive for our alliance, and I've observed a correlation between teams choosing mecanum wheels and teams dropping down our pick list due to poor manipulator design.

Also, if you're the kind of team that gives teams grief for making choices differently than you and assume teams were too stupid and biased to pick your obviously superior robot based on its wheels, maybe you're not the kind of alliance partner we would want to work with?

[MARS_James]

Originally Posted by Chris is me

there's a correlation between teams choosing mecanum wheels and teams with poor manipulator design.

Despite formerly being on 1523 (who has used mecanums since 2011) with the OP for years I agree with all your statements except for the above, where is the data to support that statement since mecanums have nothing to do with a manipulator?

[Andrew Schreiber]

Originally Posted by MARS_James

Despite being on 1523 (who has used mecanums since 2011) with the OP for years I agree with all your statements except for the above, where is the data to support that statement since mecanums have nothing to do with a manipulator?

Purely anecdotal. My experience supports this claim but I cannot say that there is correlation with any sort of certainty.

[Chris is me]

Originally Posted by MARS_James

Despite being on 1523 (who has used mecanums since 2011) with the OP for years I agree with all your statements except for the above, where is the data to support that statement since mecanums have nothing to do with a manipulator?

Correlation doesn't necessarily imply causation here, and mecanum robots aren't considered by us to have poor manipulators *because* of their wheel choice. I'm trying to say that many teams that have mecanum wheels didn't get picked for other reasons as well, not just their wheel choice.

As for data, the robots that are near the bottom of our pick lists or on our DNP lists are more likely to have mecanum wheels than the robots near the middle or top of our pick lists. I could publish our Finger Lakes pick list from this year if you really want hard numbers, but it's just a trend I've noticed. There are exceptions, and I'm reasonably sure that 1523 would be one.

[pastelpony]

We saw a lot of mecanum-powered robots at the Pine Tree district event earlier this year. Generally, mecanum robots weren't really good at offense, but were crushing in defensive scenarios (important in an event where both teams in the finals relied on parking at the 1-goal and firing.) However, like most teams, we wanted offense over defense. Unless the mecanum bot isn't one dimensional, we don't really have them high up on our list.

[MARS_James]

Originally Posted by Chris is me

Correlation doesn't necessarily imply causation here, and mecanum robots aren't considered by us to have poor manipulators *because* of their wheel choice. I'm trying to say that many teams that have mecanum wheels didn't get picked for other reasons as well, not just their wheel choice.

As for data, the robots that are near the bottom of our pick lists or on our DNP lists are more likely to have mecanum wheels than the robots near the middle or top of our pick lists. I could publish our Finger Lakes pick list from this year if you really want hard numbers, but it's just a trend I've noticed. There are exceptions, and I'm reasonably sure that 1523 would be one.

Maybe it is a region thing, for the most part in Florida the mecanum bots do not have poor manipulators, though a lot do follow your statement about drivers not being as well versed with driving as their traditional drive counterparts. Like you said their are exceptions to every rule though your offer of data does bring up something, if possible I think it would be interesting for someone to compile data from events and see if there is a correlation between drivetrains and their ranking, and elimination selection/performance.

[thatprogrammer]

Originally Posted by MARS_James

Maybe it is a region thing, for the most part in Florida the mecanum bots do not have poor manipulators, though a lot do follow your statement about drivers not being as well versed with driving as their traditional drive counterparts. Like you said their are exceptions to every rule though your offer of data does bring up something, if possible I think it would be interesting for someone to compile data from events and see if there is a correlation between drivetrains and their ranking, and elimination selection/performance.

1065 has a SOLID robot this year, despite having mecanum wheels. We picked them during elimination matches and made it to semi-finals.

[MARS_James]

Originally Posted by thatprogrammer

1065 has a SOLID robot this year, despite having mecanum wheels. We picked them during elimination matches and made it to semi-finals.

I think Moose had a drop down traction wheel on each side this year

[Max Boord]

Originally Posted by thatprogrammer

1065 has a SOLID robot this year, despite having mecanum wheels. We picked them during elimination matches and made it to semi-finals.

1065 was not pure mecanum. They had jump drive which was powerful enough to push 233's 8WD sideways. Im shocked we where able to pick them in Orlando as the #4 seed.

[thatprogrammer]

Originally Posted by MARS_James

I think Moose had a drop down traction wheel on each side this year

Yeah, they had 2 1" diameter traction wheels bolted together on each side. As fart as I know, they only used them during pushing matches though. *So when you tried to stop shots into the goal *

[Max Boord]

Originally Posted by ChuckDickerson

In my fantasy world I would dearly love to see Teh Chezy Pofs do mecanum

Who knows, Skystalker V2 may come equipped with 8 wheel drop center mecanum.

Originally Posted by ChuckDickerson

mecanums are never on Einstein.

They where this year.