pic: 1675's REAL IRI Upgrade
 

Re: pic: 1675's REAL IRI Upgrade
 

Was this real or a joke?

Re: pic: 1675's REAL IRI Upgrade
 

For realsssss.

-RC

Re: pic: 1675's REAL IRI Upgrade
 

Chris,
You may have just started a massive debate.
Frightened,
-Duke

Re: pic: 1675's REAL IRI Upgrade
 

I wanted to try it on the practice field but the kids took the treads off and wouldn't let me.

Re: pic: 1675's REAL IRI Upgrade
 

That looks like a big improvement. Design truly is an iterative process. Too bad other mecanum teams of the past never thought of this. :ahh:

Re: pic: 1675's REAL IRI Upgrade
 

honestly i wanted to do the same to our wheels...

Re: pic: 1675's REAL IRI Upgrade
 

Very interesting. I would imagine that the driving style was changed to tank drive rather than the typical mecanum pattern, is this correct?

Re: pic: 1675's REAL IRI Upgrade
 

Unless tank treads now have the ability to strafe, i would say no.
Not hating on 1675 or anyone, but I'm not sure why everyone's praising this as if its a new design or a radically different/improved design, in comparison to a normal tank tread drive. Unless you can somehow strafe, the wheels are now no different than a normal tank tread drive--maybe even worse because the tread is zip-tied and not against a flat surface.
However, i would love to be disproven on this.
-duke

Re: pic: 1675's REAL IRI Upgrade
 

no, its because a lot of people equate mecanums with dog poo. they point out things like "no bot on einstein has had mecanums" and things like that.

I consider the picture a DOWNGRADE. mecanums work if you do it right. gear them high and try to keep the weight semi-balanced.

I know there will be some angry replies to come from this from the "mecanum haters" out there.

Re: pic: 1675's REAL IRI Upgrade
 

This "upgrade" was a friendly joke / prank from the kids on 1625. They obviously removed them, despite some of us friends teasing them that it was a big improvement. 1675 responded by hiding hundreds of mecanum rollers in 1625's tools.

Yeah, how dare we point out "facts" and stuff in an engineering discussion. :)

I think Einstein may not be the best sample for pointing out a correlation between traction drives and success, but I certainly can name far, FAR more top robots with traction drives. I certainly don't think the best teams are just too sucky at using mecanum drives to appreciate them!

Re: pic: 1675's REAL IRI Upgrade
 

Facts? Chief Delphi is not a place for facts chris. :)
Im curious as to how many top teams have actually tried Mecanum. Because its not that the people that dont use Mecanum are the top teams, its that the top teams seldomly use mecanum.
Chris, you seem to know every team :p , so whats one of the best teams you saw this year ( or any year) that used mecanum? Because im pretty sure the big name teams (71, 111, 67, 148, 233) have never used mecanum.
------
In other words, regarding tank v. mecanum, correlation does NOT imply causation.

Re: pic: 1675's REAL IRI Upgrade
 

Not used mecanum in competition. That doesn't mean they've never used, tested, built a mecanum robot! It's an important distinction.

The best mecanum team this year was IMO 2826, which had an alternating drivetrain. If you go by FRC Top 25, not one team is "pure" mecanum. The best team probably to go pure mecanum was 2337, but I do think they would be just as good with a traction drive.

Yes, that's true, but it's not worthless either. I made a thread a few months back called "Video of Mecanum Drive Running Circles Around Traction Drives" asking for some footage. I'm still looking. ;)

Re: pic: 1675's REAL IRI Upgrade
 

Yes i remember that thread. Excellent point, sir :cool:

Re: pic: 1675's REAL IRI Upgrade
 

well, I am lookign for a video of a tank bot crushing a mecanum bot to bits against a wall. just like the video on your wish list, you won't see it because you are looking for too big of an advantage.

the reason a lot of top teams use:

traction: they have used it for so long and thats what they are used to and have plenty of spare parts for

crab: they have plentiful human and/or capital resources or they have used crab for so long they already know the drivetrain design before the beginning of the season.

i do recall a pure mecanum system being a division finalist. curie 2008. 2171 robodogs from crown point, IN. look at some of thier footage on thebluealliance from boilermaker regional... they had that crab drive rocking... and that was under the IFI system.

octanum sounds like a good offseason project but a waste of weight and expenses... the key to mecanum is speed... gear it high (stock toughbox nano will do) and go... you can have a scale-down button if it is too quick by itself.