Video of Mecanum Drive Running Circles Around 6 Wheel Drives

[pntbll1313]

Originally Posted by gabrielau23

Even last year there were problems. If you were balancing with another robot that had mecanums, you always had to push them up. And if you went too far towards the mecanum's side, the probability of a balance just went down since there was no way the mecanums were going to be able to push a 120+lb. 'bot up the bridge.

I will have to disagree with this post. Last year we were one of the fastest robots at balancing both single and double with mecanum. WE were the ones that pushed robots up the bridge. I'm sure you had a bad experience playing with bad mecanums at your regionals but you can't generalize that all mecanum are this way. Here's a video of us lining up, lowering the bridge, and balancing all in around 4 seconds.
http://www.youtube.com/watch?v=fWYN5xVIyzw&t=11m1s

Originally Posted by gabrielau23

Our driver was EXCELLENT, so we had very few problems lining up to take shots, and we usually were able to hit 3 cycles on a bad match. Something I can tell you right now is that I really didn't see any mecanums utilize their maneuverability well enough to offset the disadvantages of us being able to
a. Either push right through them
or
b. Hit them on our way back and forth from the stations and screw up their shot occasionally.

With Mecanum at our last competition we were hitting 5 cycles with heavy defense and 7 without.

[pfreivald]

We have liked mecanum for several years because of the ease of lining up with field elements -- like the feeder slot. (We won a regional in 2010 and didn't this year, but despite that I can say without hesitation that this is the best robot we've built so far. That said, we did use octocanum, not straight mecanum, but we rarely dropped the traction wheels at FLR or Buckeye.)

[rwkling1]

Originally Posted by Chris is me

I've almost had enough of just arguing, debate, and throwing words back and forth at each other.

I want to challenge one very, very common claim about mecanum drives - the premise that mecanum drives are significantly more maneuverable than a six wheel skid, and in particular that mecanum drives can "run circles" around their six wheel skid defenders. I've personally never seen a mecanum behave that way.

So here's your challenge. Find a video that demonstrates a mecanum drive doing just that - being defended actively by a skid steer drive and repeatedly scoring successfully by outmaneuvering the opponent.

Do not post anecdotes. Don't post stories about how your team totally dominated Whatever Regional with your mecanum drive. I'm looking specifically for video - something that we can all objectively observe and critique.

If what I think is the case is true - nothing will be found.

If the opposite of what I think is true happens - we'll have a pretty cool video to watch and use as a reference point when debating the merits and drawbacks of a drive system.

Go!

I believe you're looking for something like this:
http://www.youtube.com/watch?v=Ogy65hEPIXk
2052 used mecanums better than I have ever seen

[cmrnpizzo14]

I believe you're looking for something like this:
http://www.youtube.com/watch?v=Ogy65hEPIXk
2052 used mecanums better than I have ever seen

Good call, they use mecanums extremely well. Unfortunately it has already been said on the previous page.

Originally Posted by PVCpirate

I know, old thread, but does anything in this video qualify? It's 2052's mecanum showcase video. http://www.youtube.com/watch?v=Ogy65hEPIXk

See the previous page for discussion about it.

[robowrestler]

At a recent meeting we had our robot from this years game with a 6 wheel drive and the mechanum bot out.The kids driving the mechanum couldnt get around the 6 wheel bot enough or by anymeans run circles around it. also if our six wheel cought the mechanum and started pushing it it was all over. so in the end mechanum is manuverable but its not great

[robowrestler]

[/quote]
Well-practiced Mecanum <= Well-practiced 6 Wheel Drivetrain
Well-practiced Mecanum >= Good 6 Wheel Drivetrain
Little-practiced Mecanum < Good 6 Wheel Drivetrain[/quote]

this is just abouat the best thing i have read...good drivers and practice make a great difference

[DsRandhawa3244]

(I'll post videos later, I'm not able to get to them now)

I was a driver for 1259 this year, and we used 4 wheel mecanum. Although I still feel we would have been a better robot with tank drive, we used the mecanum as well as we could. In Wisconsin I was able to outmaneuver some of the opposing alliances (with tank drive) with a combination of strafing and spinning to get to the pyramid so we could start our 3 level climb.

Would I have been able to do that with tank? Probably...chances are with tank we wouldn't get into situations where we had to really try hard to outmaneuver other robots. But the mecanum allowed us to move in dimensions that tank robots couldn't, and in the small, cramped side lanes on either side of the field near the pyramids, I think that additional degree of freedom helped a little bit.

A quick aside--this has befuddled our programmers for some time now. Our robot strafes almost perfectly on smooth floors, like tile, or the traditional wooden gym floors. Yet, on the field at both Wisconsin and Duluth, strafing was slow, and required a lot of manual adjustment on my end to do well. Trying to strafe with just one joystick meant turning while moving in one direction. It was our first year doing mecanum, so if anyone's able to point us in the right direction, that'd be swell. We thought it was the individual spindles on the wheels slipping, but I've seen other robots use 6" mecanum wheels from andymark no problem.

[Andrew Schreiber]

Originally Posted by DsRandhawa3244

(I'll post videos later, I'm not able to get to them now)

I was a driver for 1259 this year, and we used 4 wheel mecanum. Although I still feel we would have been a better robot with tank drive, we used the mecanum as well as we could. In Wisconsin I was able to outmaneuver some of the opposing alliances (with tank drive) with a combination of strafing and spinning to get to the pyramid so we could start our 3 level climb.

Would I have been able to do that with tank? Probably...chances are with tank we wouldn't get into situations where we had to really try hard to outmaneuver other robots. But the mecanum allowed us to move in dimensions that tank robots couldn't, and in the small, cramped side lanes on either side of the field near the pyramids, I think that additional degree of freedom helped a little bit.

A quick aside--this has befuddled our programmers for some time now. Our robot strafes almost perfectly on smooth floors, like tile, or the traditional wooden gym floors. Yet, on the field at both Wisconsin and Duluth, strafing was slow, and required a lot of manual adjustment on my end to do well. Trying to strafe with just one joystick meant turning while moving in one direction. It was our first year doing mecanum, so if anyone's able to point us in the right direction, that'd be swell. We thought it was the individual spindles on the wheels slipping, but I've seen other robots use 6" mecanum wheels from andymark no problem.

FIRST fields ain't level. Also, carpet != wood/tile you'll get drastically different performance characteristics.

[Madison]

Originally Posted by rwkling1

Not going to look through 6 pages of comments, I just put in my response

How can you reasonably expect anyone to take your response seriously when you didn't care to take theirs seriously?

[connor.worley]

To be fair, mecanums have a really really good installation effort / cool factor ratio.

[indubitably]

http://youtu.be/rJoqeiuX3lA?t=1m43s

4096 handled the defensive bots well in this match but again, it doesn't necessarily support the mecanum > 6WD argument, just an example that was requested.

[Gregor]

Originally Posted by connor.worley

To be fair, mecanums have a really really good installation effort / cool factor ratio.

Which make them perfect for demo robots, assuming there will be a flat floor.

[EricH]

Originally Posted by Andrew Schreiber

FIRST fields ain't level. Also, carpet != wood/tile you'll get drastically different performance characteristics.

This. Also check weight distribution--a climber sticking out the side could be enough to throw off any straight-line maneuvers not going through that side. I don't know how many teams that use mecanums use suspensions any more, but I'd consider a suspension at least worth a look if you don't want to do corrections.

The last truly flat field--no under-carpet bumps or over-carpet bumps--was not 2011. 2009 doesn't count (and had a bump anyways--there was carpet exposed at the edges). 2007, if you weren't climbing a ramp; 2005 if you count the ramps. Yep, 2005. Until you factor in the loading-zone triangles, in which case we haven't had a truly flat field since before automode--in 2002's Zone Zeal.

[gabrielau23]

Originally Posted by pntbll1313

I will have to disagree with this post. Last year we were one of the fastest robots at balancing both single and double with mecanum. WE were the ones that pushed robots up the bridge. I'm sure you had a bad experience playing with bad mecanums at your regionals but you can't generalize that all mecanum are this way. Here's a video of us lining up, lowering the bridge, and balancing all in around 4 seconds.
http://www.youtube.com/watch?v=fWYN5xVIyzw&t=11m1s


With Mecanum at our last competition we were hitting 5 cycles with heavy defense and 7 without.

Your opinion doesn't count because you're closer to Michigan than we are. DDD

Haha, okay, point taken. But I would venture to say that your team was an exception to the rule at pushing robots up the bridge in Rebound Rumble, n'est-ce pas?
And congratulations on your 10,000 lakes performance!

[gobrewcrew95]

Proof that a 6wd robot is superior...

http://www.youtube.com/watch?v=Pu1VCYP4doo

I don't see them using mecanums...