Re: Video of Mecanum Drive Running Circles Around 6 Wheel Drives
 

I think a 6 wheel drive train would have trouble doing this: http://www.youtube.com/watch?feature...shqAVY#t=72 s

Re: Video of Mecanum Drive Running Circles Around 6 Wheel Drives
 

That is the true definition of tenacity. Awesome.

Re: Video of Mecanum Drive Running Circles Around 6 Wheel Drives
 

WOOWWW. :eek:
I've never seen this video before, I'm sure people already told him before, but that 971 driver deserves an award for awesome tactical driving! Sweet moves!

Re: Video of Mecanum Drive Running Circles Around 6 Wheel Drives
 

With TBA back up:
In the red front zone is a mecanum driving like a tank around a mecanum driving like a mecanum.
http://www.thebluealliance.net/tbatv/match/2010ok_qf1m2

Re: Video of Mecanum Drive Running Circles Around 6 Wheel Drives
 

I appreciate what you tried to do with this thread, but it doesn't look like any such video really exists.

I'll give you the reasoning that 1747 chose mecanum this year though.

1: Ability to strafe in front of the scoring grid.
2: help avoid defensive interaction.

Reason 2 was considered to be more secondary through the design process. The students also decided on a very aggressive ratio in the Tough Box Nanos that we are using (8.45:1) giving us a calculated maximum speed of nearly 14fps. Using a ratio like that completely prevents us from serving any kind of defensive role and means our drivers must use that speed to an advantage.

With the drive train (finalized) running on day number 9 of build season we were able to put it through its paces and even with as fast as it is, the robot has proven to be very easily controllable.

I guess the real relevance to this thread is that the issue I believe you to be addressing (Mecanum will lose out to a 6 wheel when you're considering defensive interactions) is absolutely the truth, but I don't believe it to be the reason teams used for choosing them.

Sorry if I missed your point.

Re: Video of Mecanum Drive Running Circles Around 6 Wheel Drives
 

I see no reason why a 4wd or 6wd with wheel in the same position couldn't do the same.

Re: Video of Mecanum Drive Running Circles Around 6 Wheel Drives
 

sometime this week we plan to run our 2010 robot (12-1 bane bot p80's) direct driving gen 2 8 inch mechanums from andymark. vs this years robot (4 cims into 2 stock tough-boxes with a 28 tooth sprocket on gearbox driving 24 tooth sprockets on wheels) with 6 diam tank drive with the wheels on the ends being 6 inch omnis. i am pretty sure that the tank drive is going to

A. drive circles around the mechanum
B. push the mechanum everywhere
C. burn through batteries at 3x the rate of the mechanum (we blew the 120amp break the other day :ahh:


this is with the vet driver from 2010 returning to drive the mechanum, and no driver practice on the tank.

ill post some video here.

Re: Video of Mecanum Drive Running Circles Around 6 Wheel Drives
 

His name is Scott and he is a Jr. and Team Captain this year. He is just itching to get a hold of our 6 wheeler with automatic shifting. If I had to bet my pink slip against a mechum and our 6 wheeler. I would go our six wheeler any time.

Roy

Re: Video of Mecanum Drive Running Circles Around 6 Wheel Drives
 

I'm really confused - it seems your team picked mecanum for the reason I am addressing, which you claim is (un)true.

More or less, I'm challenging the idea that mecanum drive's capabilities allow it to avoid defense.

Re: Video of Mecanum Drive Running Circles Around 6 Wheel Drives
 

From our point of view, beating defense with a mecanum is not about avoiding the defense so much as it is about redirecting the defense. You have to accept going in that you will get hit.

If they ram you from the side, don't try to fight the ram, ride with it and circle-strafe so that the force of their robot actually ends up pushing you to where you want to go. If they come from the front, turn 90 degrees on the spot and drive a little to the side so that the brunt of their force knocks you back into a position where you face the goal (rather than shoves you backwards) and then get behind them as momentum carries them forwards.

So no, I don't believe a mecanum can run circles around a 6WD. In fact, it's likely that 6WDs will run circles round most mecanums. But I do believe that a mecanum drive can redirect impacts far more successfully than a tank can.

Also, I'd love to see a tank drive pull off the Vin Diesel maneuver coming out of the lane. A well-programmed and well-driven mecanum can turn a 180 while moving forwards and not slowing down. Tanks will either have a time drain when having to turn around or will have to be able to move the tube from one side of the bot to the other.

Re: Video of Mecanum Drive Running Circles Around 6 Wheel Drives
 

This is called a J-turn or a bootleg turn, not the Vin Diesel maneuver. Also, please don't assume anything in any of his car movies is correct information... :D

It's weird to feel old and crotchety at the age of 23...

Re: Video of Mecanum Drive Running Circles Around 6 Wheel Drives
 

I really don't think that is true. Last year in Breakaway our team managed to keep the scores minimum against a robot with mecanum wheels eventhough we were using the wheels supplied in the kit

Re: Video of Mecanum Drive Running Circles Around 6 Wheel Drives
 

You know, I'd been looking for a technical term for that forever. "Vin Diesel maneuver" was a joke name our mentor gave it, and it kinda stuck. Thanks for giving me something less silly to call it :P

Re: Video of Mecanum Drive Running Circles Around 6 Wheel Drives
 

6wd is power and pretty good with turning mecanum can run away and turn like its goin outa style either way they make pretty good robots it all depends on the end effector that is what makes the robot a winner

Re: Video of Mecanum Drive Running Circles Around 6 Wheel Drives
 

A good defensive robot (treads, 6WD, or 8WD) should be able to push around a mecanum robot no problem. Depending on how they are set up, they MAY be faster. However, with any tank drive robot, if you want to score (atleast in this years game), you have to come onto the pegs perfectly: If your off, you have to backup and try again.

There are cases where one is better than the other. I don't feel that Mecanum could perform well enough against a good defender to account for its pushibility. But thats just an opinion.