As part of my push to improve print quality, I’ve been experimenting with microstepping. The SparkFun EasyDriver boards look like an interesting alternative to the standard RepRap driver boards. They only drive 750mA compared to the 2A for the RepRap boards, so they may turn out to be underpowered for RepRap use, but so far they are working pretty well. They can operate at full, 1/2, 1/4, or 1/8 step. I’ve been able to get the standard Gen3 firmware operating the at 1/8 step at pretty reasonable speeds (the fast traverse speed will definitely be lower than what I’m used to, though). The smooth movement is very nice!
For a RepRap running on the Gen3 (Sanguino) firmware, the motor power requirements are primarily driven by the need to provide instantaneous large velocity changes. So the second part of this effort will involve firmware changes to incorporate acceleration into the movement. This should greatly reduce the stepper power requirements and make the lower power drivers a better fit.
However, the acceleration code is still a long way from being done — more about that later.
To make the EasyDriver boards easier to use, I’m building a board that can hold 4 of them. The board just makes the wiring cleaner, and has dip switches that allow easy selection of the stepping modes.
