pic: Potential Off Season Drive

[Joe G.]

Originally Posted by cad321

The mecanum wheels are raised 1/8" above the ground when the traction wheels are down. So I would say that there is a good possibility of the mecanums hitting the ground should the bot start tipping around.

I would try to avoid this if at all possible. Not only do you loose traction and forward force, but mecanum wheels can do some unpredictable things when they don't contact the ground evenly. This is one of the reasons that it's more common to have the traction wheels at the corners rather than the inside of octocanum/butterfly/nonadrives.

Is there a particular reason that your chassis paneling needs to be so tall, extending above the tops of the 6" wheels? Seems you could save quite a bit of weight by chopping the top few inches off of the frame.

I would consider trying to integrate your initial gear reduction, or at least the final stage of it, into the module. This would allow you to use a dead axle for the module to pivot about, giving your sideplates and module much better rigidity exactly where they need it. This will be easier if you make the module pivot about the Mecanum wheel. Many similar designs are able to get away with a single stage reduction this way, by gearing to the faster wheel first, then incorporating further reduction into the belt run to the traction wheel.

I'd be concerned with the gap in the middle of the frame in conjunction with the thin, unflanged parallel plate construction. Your frame is four thin parallel plates in the middle, which can bend with each other easily. Either fill in this gap by making the front and rear chassis members one piece, or thicken or put some flanges on the chassis side rails to stiffen them up.

Agreed, those pistons look a little small to be lifting a robot on. I like what you're doing with the single piston across the top though. Just make sure your hard stops are well defined and integrated, to ensure that it behaves as expected.