pic: Swerve Drive Can SolidWorks Concept (cheap version)
 

Re: pic: Swerve Drive Can SolidWorks Concept (cheap version)
 

How heavy is it?

You might consider placing some standoffs between the two walls of the tubing to prevent them from moving in relation to each other.

Re: pic: Swerve Drive Can SolidWorks Concept (cheap version)
 

According to SolidWorks, it weighs 1.3 lbs or so.

As for standoffs, there will be spacers between everything, at least on the wheel shaft.

I could also put some bolts through with spacers as well, as you suggest. A good point :) thanks.

Re: pic: Swerve Drive Can SolidWorks Concept (cheap version)
 

Looks Great, Nice Design. You may want to support the bottom of the Module with a lazy susan or with a circular piece of plastic.

Also, why not use Hex Shafts, you woudn't have to worry about keys ;)

-RC

Re: pic: Swerve Drive Can SolidWorks Concept (cheap version)
 

Modules themselves look fine, but that weight can be reduced by facing that wheel on a lathe a bit more or with a COTS wheel from AndyMark. The wheel looks like a beefy part of that weight.

Re: pic: Swerve Drive Can SolidWorks Concept (cheap version)
 

It would be more taxing on the team, but based on what I've heard I would recommend tapping the ends of the live axles and putting a bolt in them rather than using a c-clip.

Also, to prevent racking you could make this out of 3" box extrusion and make it a little longer at the bottom. That way you could have at least 1/4" wide strips running between the sides at the bottom. The aluminum already turns in at the bottom, so making it longer and cutting a hole (rather than a whole slot) for the wheel would easily allow you to do this.

Re: pic: Swerve Drive Can SolidWorks Concept (cheap version)
 

It looks like they're using snap rings not c-clips.

I would highly reccomend snap rings so long as you have the ability to make the groove the correct size. Nothing beats their ease of use.