Dual Z steppers, linked or not?

I see some machines with dual steppers and a toothed belt tying them together. I don’t understand why this is done. If one of the steppers is skipping steps then that needs to be fixed. Surely if one stepper skips and the other doesn’t trying to force the errant stepper will damage it?

The only up side I see is that if you manually move the Z with the motors off, it’ll stay level. So just don’t do that.

unless the motors are getting the exact same charge they are slightly out of phase with each other and every once in a while you need to check them making sure both sides are level to your nozzle… belting the Zs together Eliminates those problems but where can you get continuous belts exactly the size you need?? except sewing or gluing the belt…
I am currently having this issue with the REP-Rap Wallace I am currently building For example I am reusing my parts from my Prusa Mendel to make a Free 220X220X270 printer fro building masks but I am running into this Unbalanced Motors Issues as well to solve this I might have to switch around the motors to get 2 that run right or break out the 5 motors I bought for my I3 Woody that is currently on the way… but now the one printer that was still functional is now down with thermometer Issues I even replaced the bead with another 100K Thermoster now I am getting readings as high as 90C from just sitting I know its a Resistance Issue I just have to set the correct number on thermoster type…

Seems like most people feed both motors from same driver

Again most people use an idler.

I just can’t see the tiny difference will not be swamped in back lash.