ErikZalm/Marlin — pull request #208 by Enchiridion (2012-08-04 08:25:09+00:00)
Title: Added support for dual Z axis stepper drivers

I've added support for dual Z axis stepper drivers (using 1 stepper driver for each Z axis stepper motor).

On my Prusa Mendel, running both my Z axis steppers off a single driver was causing the driver (even with a heatsink + fan) to run very very hot (I have rather beefy Z steppers). So I added another stepper driver (I'm using a RAMPS motherboard and it had a spare driver slot) and can now run each motor individually. My stepper drivers run nice and cool now.