HELP?!? with Omnidirectional/Crab Drive

[KMAC42]

Hey all,

Oops, actually called swervedrive, but we're modifing it

We've decided to go with a omnidirectional drive that has the front two wheels banded together and the back to wheels banded together so that those two pairs always face the same direction.

This is our first year doing omnidirectional drive, and rather than reinvent the wheel, we were wondering if anyone could give us a hand with the design. We would aperciate IE drawings, program code tricks, transmission design, and anything else i'm too stupid to remember. Thanks for all the help

Team 706

[Ianworld]

Well first off what you're looking at is making a swerve drive robot. They are complicated, often require a lot of machining and good coding. I'm going to recommend that you don't just try to do this on a whim. My team back in 2002 thought we could just make a swerve drive in 6 weeks and it ended with a robot that couldn't drive at all. I'm going to recommend that you try putting this on the back burner and do it as an off season project.

That being said, if you want to go ahead the more power to you, but don't say I didnt' warn you. A good place to start is with a CD-media search of swerve drives. Hopefully this link will work
http://www.chiefdelphi.com/media/search/results/28297

If not just do a search for "swerve" and you'll come up with pages and pages of pictures to start with.

I don't know of a good source of swerve drive drawings, but hopefully a team that has built one succesfully(my team has yet to ) will offer their services. Things to look into are using the Nothing but dewalt gearboxes to provide a nice gearbox for each wheel, I think HOT made a set up like that.

Other than that Good Luck (and please have a back up plan )

[artdutra04]

Originally Posted by Ianworld

That being said, if you want to go ahead the more power to you, but don't say I didnt' warn you. A good place to start is with a CD-media search of swerve drives. Hopefully this link will work
http://www.chiefdelphi.com/media/search/results/28297

All search results are only good for a short while, so linking to them only works for at most 30 minutes to maybe an hour. (Maybe Brandon can offer insight into the actual time?) Rather than linking to the search results, link to the tag pages.

http://www.chiefdelphi.com/media/photos/tags/swerve
http://www.chiefdelphi.com/media/papers/tags/swerve

Edit: I think the search results are also linked to your SESSIONID variable, which is unique every time you visit and/or log into ChiefDelphi. So linking one person's search results would probably not work for anyone else.

[supertroopa86]

Are omnidirectional wheels Legal for use in this years FIRST robotics compitetion

[Billfred]

Originally Posted by supertroopa86

Are omnidirectional wheels Legal for use in this years FIRST robotics compitetion

If it passes the Robot section of the manual (all of it), it's legal.

[KMAC42]

Yes we have a back up plan, our team has become quite good at working and building the basic two-wheel drive chassis and drive train so we've got that to fall back on.

found a couple of cad drawings, what did you mean by "the Nothing" is that a typo or a gearbox, please save the ignorant.

[jgannon]

Originally Posted by KMAC42

what did you mean by "the Nothing" is that a typo or a gearbox, please save the ignorant.

I believe that Ian is referring to the "Nothing But Dewalts" whitepaper that you can find here:

http://www.chiefdelphi.com/media/papers/1592

[eshteyn]

Guys i would highly suggest sticking to your back up plan, not to say that you can not do it but you only have 5 and a half weeks left. If you want to explore swerve drive then do it in the off season. It requires a lot of custom machine work and a lot fo customization. Seriously consider not exploring this drive system.



-eugene - mechanics/electronics/machining

[woody]

I agree with many of the above posts. A 'swerve drive' is potentially quite usefull, but it is a much better off-season project for your first time out. Our team (33) tried to build one for 2005 and it was abandoned after our first regional due to unforseen complications (including drivers not having nearly enough practice.) If you want some good technical tidbits on the little quirks we found, you should PM our mentor Jim Zondag.
Good luck!