pic: Swerve Design

[magnets]

Originally Posted by z_beeblebrox

Solidworks estimates 36lbs, which seems pretty reasonable.

The top and bottom plates and the module sides are .25" aluminum. Would any pocketing on those be useful?

If you've got machining resources (you probably do if you're going with swerve), then it's probably worth it to pocket the plates. 0.25" aluminum is really strong, so you can make big pockets.

A few ideas for weight savings

You can shrink the module plate by making the whole thing a big triangle and pocketing the center, like this. Your current design looks like you're making them wider so you can add the little support thing. You shouldn't need one because the lower axle with the wheel on it will make the thing stiff enough.

The big green plates mounted to the frame could also get smaller by making them curved, and you could probably mount the steering motor directly to the frame, with no need to make the green plates go out that far.

The idea for using the bike parts for the bearing is really neat.

[z_beeblebrox]

Based on the suggestions given, I've made some changes to the design. I've removed the spacers from the module and added pockets. I also mounted the steering motor to the frame rails and reduced the size of the gearbox plates to what was actually needed. It's now about 38.5lbs. (For comparison, the 2013 KOP chassis with 4 CIMs weighs about 32.)

I also noticed that the first iteration was several pounds too light; I hadn't counted the correct mass for the the motors and gearboxes.

Edit: I added some pocketing to the gearbox plates and took off another .5lbs.

[yash101]

That is quite lightweight! If you want to get even lighter, I notice that there is some material that won't necessarily add any structural value, so there are many places to drill holes at to reduce weight! Hopefully you use this in 2014 so I get to check it out at the competitions!

[z_beeblebrox]

Originally Posted by yash101

Hopefully you use this in 2014 so I get to check it out at the competitions!

I'm almost certain we won't run a swerve drive in 2014. It's heavy and machining and software intensive for little performance gain over a simple 6WD. This season, we want to build a simple, elegant effective robot quickly and have plenty of time to work on the practice robot, software and driver practice. It would take our team about a week extra to make a swerve drive, a week we can't afford to lose. We might build a prototype the next off-season, though.