I have a rigged robot set up, and everything is ok so far, but what I'm having trouble with is taking a rotational value of one shape, setting it as a driver, then having the driven represent the driver's values but inverted:
Driver = +90 Degrees
Driven = -90 Degrees
Sure it's incredibly simple but I'm more familiar with AE expressions than C4D Xpresso...
open the xpresso and either set the Range Mapper/Output Upper to -360 or remove the Range Mapper entirely and place a Negate node (found in New Node/Xpresso/Calculate) in it's place (connecting the in and out like the range mapper was)