Originally Posted by
yngndrw
I have a set of these boards and have checked out many things with the creator.
The input marked 7V is fine running on about 10 or 12V. Don't go much over this as it may cause the regulator to overheat. It needs to be atleast 7V.
The input marked 12V is your motor voltage. This can be upto 36V, but 36V is the absolute maximum. Do not go over this at all, it is best to leave a safety gap. I will be using around 24V, maybe 30V.
They are setup for 1A per coil using two 0.8Ohm resistors. I personally changed mine to 2A per coil, which required removing the 0.8Ohm resistors and replacing them with 0.4Ohm resistors. I have only changed one upto now but it works fine with fan cooling.
As for temperature, I'd suggest that you measure it. As long as the temperatures don't go over 80C it's fine. I found that mine was running at 50-60C stock without a fan. I now run mine with the extra current mentioned above and a small fan - It doesn't go over 50C and rarly goes over 40C. I will get a 50mm fan for each board and make a mounting plate to sit the fan right over where it's needed. I might also put a bigger heatsink on as the heatsink is too thin.
They are pretty good boards and I managed to get 1500RPM with over 500RPM/s acceleration (No load) on a 4A Nema 23 stepper running at 2A / 24V.
Good luck.