3Step Overview
The 3Step driver board is a 3 axis unipolar stepper driver board
which takes step/direction signals from a PC, and uses them to move 3
stepper motors to control a CNC machine, or anything else for that
matter, that has 3 motors.
The design does not have any current limiting functionality built in, it simply uses a PIC processor and 12 mosfets to drive the steppers directly. If your stepper motors require current limiting functionality, this has to be added externally via current limit resistors, or a 'high side chopper' circuit.
Because this was always intended to be a KISS design (Keep it simple stupid) I do not have information on how to build a high side chopper, and only address the use of current limit resistors on this site.
As well as being a KISS design, you'll find that I gloss over a lot of the underlying theory behind steppers and the electronics. Partly because if you want a simple design that 'just works' you really don't need to know all the gruesome detail, and party because I'm faking some of it anyway!
There are plenty of complex, high performance stepper designs on the web, some using exotic components, some not. Some Open source, some requiring proprietory software to run. Check out the links page.
On, ever onwards, to the Specifications page.