[rich2202]

Originally Posted by Michael Hill

Pardon my ignorance, but I'm not entirely sure what you mean about need a gearbox for each motor. You only need 1 SuperShifter for each set of 2 motors (generally 1 gearbox on each side).

If you want a ratio that is different from the ones provided, you have to put something (another gearbox) before or after the Super Shifter. The Andymark page says their transmissions accept either: 1) 2 CIM motors, or 2) 2 AM Planetary Gearboxes. So, if you want to raise the reduction ratio, you add a AM Planetary Gearbox prior to the Transmission. Since each transmission accepts 2 motor inputs, you need 2 AM Planetary Gearboxes if they are put between the CIM and the Transmission.

However, if you gear down after the transmission (CIM->Transmission-> AM Planetary Gearbox), then you only need one AM Planetary Gearbox. This assumes you don't exceed the capabilities of the AM Planetary Gearbox (can it accept that much torque on the input?).

Any reason why you aren't looking at the Vexpro ball shifters?

My team is Andymark fans. They assume Andymark stuff will take the beating of a normal FRC competition. I'm sure once we gain experience with transmissions, they will be more open to other options.

The AM Shifter only has two reductions as the final reduction is meant to be in the sprockets connecting the wheels to the gearbox output. This is easier to tune than a direct drive system.

Thanks. Stock ratios (sonic and super shifter) are fine for typical FRC applications. Use AM Shifter if you want to fine tune with last gear.

I assume we will direct connect 2 CIMs to the Transmission. Glad to know the AM Planetary Gearbox is not normally used between the CIM and Transmission.

I assume the 4.0:1.0 ratio is when you want a lot of power to push around another robot, or fine motor control (such as when balancing). Whereas, the 2.6:1.0 gives you a little more control when driving slow.