This design I have worked on for almost a year. Its ready to make chips. I invite you to review the video of this system, as it is easily the most user friendly chassis available. The system can use ANY amount of Gecko's G251x drivers up to 6 axis. The end user can add them as required to save on cost, or to offer more support when adding dual motor drive systems. It's got tons of features check it out below.

Gecko 6 Axis Chassis 3 G251X's 48V 12 5A 3 NEMA 23 300oz in 3 5A Motors | eBay