Hi, I've just started building a JGRO CNC, building from 3/4 inch Birch Plywood rather than MDF. I've started with the Z axis pieces and almost have that part complete. The actual build should not be a problem, as I've been a hobbyist woodworker for years. My question to the forum, is about the motor drivers. I'm pretty sure I want to use a bi-polar driver due to the increased torque from a motor in bi-polar mode vs uni-polar. I have a couple Big Easy driver boards that I bought from Spark Fun Electronics, which seem to be quite nice, but, I'm worried about their ability to handle the rated 2A for long periods of time, even with heat sinks. I found the TB6560 boards on e-Bay, and they looked great until I started reading about them. All of the reviews I read about these boards are from a couple years ago. Since I haven't seen any newer comments about these boards, have they been revised and are now relatively good, or have people just stopped using them? Any direction would be appreciated.