pic: 1675's REAL IRI Upgrade

[Hawiian Cadder]

dunno if this is quite what you wanted Chris, but in this video 1318 litteraly drives circles around the defending robot in green, 3251. Although without any other drive-train details it is difficult to tell what really happened, this is an instance where i would say a mechanum robot definitely out maneuvered at least one non-holonomic defender with ease. Although this video says little about a mechanum driving circles around a defender like 973 (substantially more tenacious than the defenders in the video) I think that it shows the capability of a mechanum drive-train to use the ability to strafe to glide between defenders in a way that would be difficult for a tank drive to do.

http://www.youtube.com/watch?v=lwv9hZgw9r0

[XaulZan11]

Originally Posted by Hawiian Cadder

dunno if this is quite what you wanted Chris, but in this video 1318 litteraly drives circles around the defending robot in green, 3251

What I see in that video is 3251 playing defense solely on 3165 (the team with the white tube) and paying very little attention to 1318. I think it is relevant to note that 3165, with what looks like a mecanum drive, did not come close to getting past the defense of 3251. When 3251 did switch to 1318 at the end of the match, they let 1318 get away when they got ready to deploy.

[lemiant]

Originally Posted by XaulZan11

What I see in that video is 3251 playing defense solely on 3165 (the team with the white tube) and paying very little attention to 1318. I think it is relevant to note that 3165, with what looks like a mecanum drive, did not come close to getting past the defense of 3251. When 3251 did switch to 1318 at the end of the match, they let 1318 get away when they got ready to deploy.

I agree that this doesn't show an example of mecanum out maneuvering tank drive, but I have to say that the 1318 drivers do the best job of using mecanums that I have seen (in my limitted experince), using the strafing when and where it fits.

[bam-bam]

This thread has been hijacked. Thank you for your time.

[Chris is me]

I had no idea 1318 was being defended in that match. They also moved very slowly and aimlessly - not exactly running circles, unless you mean the literal circular path they take?

I honestly don't see why this thread had to turn into an argument. The reason the picture exists is because of two friend teams joking about their disagreement on design choices. They're clearly able to be light hearted about this. Why not us?

[AdamHeard]

Originally Posted by Chris is me

I honestly don't see why this thread had to turn into an argument. The reason the picture exists is because of two friend teams joking about their disagreement on design choices. They're clearly able to be light hearted about this. Why not us?

You certainly encouraged a non-light hearted debate early on in the thread.

[BrendanB]

Wow another mecanum debate!

I have always been skeptical about mecanums but I wasn't solely set against using them until last year 2010 driving at an off-season event and realized how easy it is to push those wheels around the field (robot I was driving was 4wd: two pnuematic, two omni). Ever since realizing how easy it was to push them, I have zero desire to use them* unless there is a game that separates alliances from contacting each other. I could never justify a decision that would leave our robot so helpless under defense.

This year our team built a 6wd plaction robot with the mindset as rookies that we will build a robot that can simply play the game (low row + minibot that averaged a logo and a 1st place minibot at regional level. 12 for 12 deployments and 8 for 8 at STL). We knew we wouldn't be the best in most matches and designed our drivebase to be powerful on the field and pushed around many 6wd/8wd and some swerves too. Not matter how bad your upper assembly turns out, you should always design your drivebase to be one of the strongest on the field.

I have heard a lot of "they can out maneuver" or "strafe around opponents" but whenever I hear that I just want to see someone do it (and bad/stationary defenders don't count).

***no octocanums were mentioned in this post***

[Akash Rastogi]

Originally Posted by Chris is me

I honestly don't see why this thread had to turn into an argument. The reason the picture exists is because of two friend teams joking about their disagreement on design choices. They're clearly able to be light hearted about this. Why not us?

Why are so many people in this thread concerned about the merits of other teams' robots and feel the need to argue so passionately against mechanum drives? I can see plenty wrong with some of your own robots that I don't see in 1675's, for example. I won't call out case examples.

Fix your own robot's issues first, then maybe you'll have a valid enough stance on something to be allowed to preach to other people. (some of whom are mentors and also former world champion drivers)

+.02,
Agrees with Tom

Originally Posted by Tom Bottiglieri

I don't understand this debate. What teams choose to incorporate into their robot is their choice and that choice is made under their value system. Yeah sure, 1114 has never used mecanum, but not every team wants to be 1114.

[Andrew Schreiber]

Originally Posted by Akash Rastogi

Why are so many people in this thread concerned about the merits of other teams' robots and feel the need to argue so passionately against mechanum drives? I can see plenty wrong with some of your own robots that I don't see in 1675's, for example. I won't call out case examples.

Fix your own robot's issues first, then maybe you'll have a valid enough stance on something to be allowed to preach to other people. (some of whom are mentors and also former world champion drivers)

+.02,
Agrees with Tom

Show me the mentor who has never built a bad robot and I'll show you either a new mentor, a liar, or Andy Baker. One of the most important things one can do is learn from mistakes and this means that we have to make them. This means you can't discount someone's analysis merely based on the fact that they have screwed up in the past.

[Hawiian Cadder]

Originally Posted by XaulZan11

What I see in that video is 3251 playing defense solely on 3165 (the team with the white tube) and paying very little attention to 1318. I think it is relevant to note that 3165, with what looks like a mecanum drive, did not come close to getting past the defense of 3251. When 3251 did switch to 1318 at the end of the match, they let 1318 get away when they got ready to deploy.

the part about them driving a circle around 3251 was mostly a joke. I do think however, that 1318 utilized their mechanum fairly well. although they didnt do smooth lines around defenders, they were able to move through the crowd more effectively than most robots I saw at a regional level.

Originally Posted by lemiant

I agree that this doesn't show an example of mecanum out maneuvering tank drive, but I have to say that the 1318 drivers do the best job of using mecanums that I have seen (in my limitted experince), using the strafing when and where it fits.

That is kind of what i was thinking too.

Originally Posted by Chris is me

I had no idea 1318 was being defended in that match. They also moved very slowly and aimlessly - not exactly running circles, unless you mean the literal circular path they take?

The circles was a joke, the robot did do a lap around a defender. I think that 1318 was able to maneuver better than most of the other robots on the feild, and a large part of that was their drivers ability to use the strafing effectively to move through the congestion, while it obviously says nothing about robot performance at the highest level, mechanums in this case proved to work very well.

[Katie_UPS]

Originally Posted by bam-bam

This thread has been hijacked. Thank you for your time.

That's a little extreme. I mean, sure, we're not talking about the LOLz we got anymore; and, yes, there are already enough threads about Mecanum vs any other drive train, but the conversation has still been somewhat intelligent and hasn't degraded to people just yelling and blindly ignoring everyone else. Actually, this is one of the better threads I've read as far reasonably intelligent posts.

Originally Posted by Chris is me

I honestly don't see why this thread had to turn into an argument. The reason the picture exists is because of two friend teams joking about their disagreement on design choices. They're clearly able to be light hearted about this. Why not us?

I'm really enjoying this discussion. I have yet to get annoyed by people just posting their opinions without reading what others have posted. Like I just said, this thread isn't really a bad thing... yet.

Originally Posted by Akash Rastogi

Why are so many people in this thread concerned about the merits of other teams' robots and feel the need to argue so passionately against mechanum drives? I can see plenty wrong with some of your own robots that I don't see in 1675's, for example. I won't call out case examples.

Thank you for the defense, however, as a member of said team, I'm not seeing this as people pointing fingers at our robot, but the drive train as a whole.

Originally Posted by Akash Rastogi

(some of whom are mentors and also former world champion drivers)

I didn't know that people actually knew that. 2 world championships, just to give him some more cred.

[Chris is me]

***removed***

[XaulZan11]

Originally Posted by Akash Rastogi

Why are so many people in this thread concerned about the merits of other teams' robots and feel the need to argue so passionately against mechanum drives? I can see plenty wrong with some of your own robots that I don't see in 1675's, for example. I won't call out case examples.

Fix your own robot's issues first, then maybe you'll have a valid enough stance on something to be allowed to preach to other people. (some of whom are mentors and also former world champion drivers)

While I do not think it is right or fair to 1675 that they are signled out in the title and mentioned several times in this thread, debating other team's design decisions is nothing new on CD.

[Nemo]

Definitely a funny picture! Hopefully everybody else who has read the mecanum vs 6WD threads enjoys it as much as I did.

I don’ t see too many people making huge generalizations in this thread, which is good.

Here is what I will add:

1) Mecanum is in some ways easier to drive than 6WD. This is because it gives you room for error. If you miss your route to a scoring peg by a bit, you simply correct it in 1-2 seconds by strafing. You don’t need to learn ridiculously complicated drive maneuvers – just drive it like a tank and strafe when appropriate. I’m not advocating sloppy driving– I’m saying that it probably takes more practice time to be a really effective 6WD operator, because it takes longer to adjust if you miss. This is relevant for teams that don’t have a practice robot / practice field or highly experienced FRC drivers. Know of any teams like that?

2) Mecanum is approximately even with 6WD in a few categories that I have seen occasionally cited as advantages for 6WD: complexity, cost, and weight. As a basis for comparison, I’m using “kitbot on steroids” as the 6WD, compared to 6” mecanum drive direct driven with with Toughbox Nanos. The mecanum drive costs about $300 more – not a giant amount when you spend $5000+ on the kit. The weight is about the same, and it’s not really any more difficult to assemble and program than a basic 6WD. The code is provided to everyone. You can bolt a mecanum drive to the kit frame in a week and then focus on the rest of the robot, just as you can with 6WD.

3) This year we had a relatively narrow scoring zone to share with our alliance partners, and the other team was not allowed to drive into it. A mecanum robot can spend most of its time in that protected zone if somebody is feeding tubes, which partially eases the vulnerability to pushing defense. We looked at that situation and went with mecanum, thinking it would help us score faster in tight quarters. One can look back at that reasoning and argue that we made a poor tradeoff, but we did have sane reasoning to go by. It is going a bit too far to generalize to the effect that there can never be a valid reason to select a mecanum drive.

4) At the regional level, mecanum drives held up pretty well. Plenty of teams have brought home regional banners using a mecanum drive along with solid manipulators / driving / etc. There’s nothing wrong with that.
_________________

Overall, I am more of a fan of 6WD after seeing how good the best of them looked on the field this year. I was surprised and impressed by how quickly and easily some of the 6WD drivers were able to hang tubes – essentially, their driving skill gave their 6WD robots the benefits we were looking for out of a mecanum drive. That was an eye opener. We are happy with our robot and our accomplishments from this year, but we’ve been playing with 6WD prototypes this summer and will probably bring some traction next year.

[Marc S.]

I remember whatching 1675 returning the favor by generously donating 50 or so mecanum rollers to 1625.
By the way, did you guys ever find all of those?