pic: Octocanum Module

[GeeTwo]

Originally Posted by Ari423

Yeah I messed up my math when calculating the torque needed to lift the robot. I will probably end up increasing the cylinder to 2" diam. which should be more than enough torque even with the piston where it is. I would go for a 1.75" pancake cylinder, but Bimba doesn't offer that and they're the only pneumatic company I've ever worked with.

You shouldn't need 2" - Bimba does have 1.5" cylinders in both square and round pancake styles. Remember that force goes up as the square of the diameter, so 1.5" provides twice the force of a 1.0625" cylinder (to within 1%).

Originally Posted by Ari423

Since the mecanum wheel is AndyMark and the pulley is Vex, there's no easy way to attach them and make it a dead axle. Sadly, AndyMark doesn't make an 18t pulley and Vex's 4" mecanum wheel doesn't support dead-axle drive. If you have another way to do this dead-axle, I would be interested in hearing about it.

You could pivot on the mecanum, which would make the cantilevered wheel the traction wheel which has a 42 tooth sprocket, if I did my math correctly. This would be easy to mount sprocket to wheel on a dead axle. This solution would also require a change in gear ratio of your gearbox - in the direction that it will probably get simpler and lighter. This would also make high-speed mecanum your "default" drive if the pressure goes out, which may be a good or bad thing depending on your game strategy/style.