pic: Crabstyle v3

[Joe_Widen]

[cdm-description=photo]25250[/cdm-description]

[Dave Scheck]

First off, nice rendering

I find it interesting that you're using the window motors to turn your wheels. Is there a particular reason that you chose them?

I don't know much about motor characteristics, but from a practical point of view, I see them being a pain. This basically forces you to enable your robot to move your wheels, which causes you to have to set your robot up before setting it on the field. Maybe that's not a big deal, but I think that it limits your flexibility.

In the crab systems that we had in 2002-2004, we used the globe motor for steering with pretty good success.

[Joe_Widen]

O yeh, I see what you mean about that. I was thinking I'd shoot for the window motors is because they have worm gears so they couldnt be back driven.
Edit\\ Im woried that we'll get hit and it will throw off the sensors

EDIT\\ think I'm going to have it so that one window controls the left side and one controls the right side

[Dave Scheck]

Are you worried about another robot reaching down and turning your wheels to knock you off course? :ahh:

Wouldn't you be better off using the only motors in the kit with built in worm gears on something that would have a tendency to want to backdrive like an arm or a lift?

[Dan Petrovic]

So are you going to be independantly rotating the wheels with separate motors?

We have a concept for crab drive and we have two window motors. The front set and back set of crab modules rotate together.

[Holtzman]

Why does it matter if you can or cannot back drive them? Don't forget, you'll need to get a pot or absolute encoder on there to measure rotation of the module and a pretty decent closed loop feedback system to make your swerve effective. Designing and building it is only half the challenge. Getting a swerve to drive predictably and effectively is arguably harder than designing and building it.

If you intend to use this during the season, you should definitely prototype it this off season. I've seen so many teams(including my own) build a swerve and never get the full potential out of it for lack of intuitive controls and programming time.


O yeh, I see what you mean about that. I was thinking I'd shoot for the window motors is because they have worm gears so they couldnt be back driven.

[Joe_Widen]

I guess our programmer said he had everything under control on his end. So looks like building it will be the hard part. Thanks for all the feedback.