pic: Small CIM in wheel swerve

[asid61]

Originally Posted by Dunngeon

*snip*
So barring any of the current limitations discussed above, what else puts a swerve down on power compared to other FRC drive-trains (primarily 4/6/8wd to keep it simple)? Here's the main one that comes to mind.

In a 6wd all the wheels are chained together, and one gearbox of (usually) multiple motors powers all the wheels on that side. So that when your robot is being lifted/losing normal force (under defense ect.) you don't lose the power. Since (most) swerves now days have an individual module per wheel (and a single motor), this benefit is lost. When the front is off the ground, the power being produced by those wheels is simply lost. Whereas in a 6wd, that power is still being put to the ground by the rear 1-2 wheels on each side.

Obviously, this ignores things like slippage of the wheels, drivetrain ineffiencies, and other trade-offs that make it a bit more complicated. Power also doesn't scale linearly to more acceleration iirc, so keep that in mind as well.

Edit:

Let's say each swerve module has 1 CIM, this cim produces a power P.
When all 4 wheels are on the ground, the drivetrain is producing 4P.
When 1-2 wheels are off the ground, the drivetrain is producing 2-3P.

With a 6wd, assuming each side has 2 motors, the drivebase has a power of 4P. When 2 wheels are off the ground, the base is still producing power 4P because the wheels are connected and at least one is still touching the ground. (again, this is simplified a bit)

The current limitations are still the same as those on the 40a breakers on the PDB, because it's not like the slip rings are about to explode the moment you exceed 40a (probably ). The spec sheet probably has the exact curves.

The thing about 4 wheels on the ground makes perfect sense, but unless you're planning on having a pushing match halfway on a table it's largely irrelevant. Just use sailcloth for bumber material and slide away perpendicular to the opponent's robot; presumably that doesn't take all 4 motors to do, and once you're on the ground you have plenty of power to flee.