@lb said in Duet2 Stepper Driver Current Limit:
Hi,
just doing research on this "old" topic: With heatsinks on top/bottom of the driver and/or active-cooling it could be experimentally increased another 0,2-0,4A up to those 2,8? (Just thinking out loud here...)
You could recompile the firmware to allow 2.8A, but it would be at your own risk.
The point to remember is that Trinamic allows a higher current when the stepper motors are moving above a certain minimum rate than it does at standstill, because when the motor is moving, the heat dissipation is shared between all 8 mosfets instead of being in just 2 of them. Also the mosfets are on separate dies from the controller chip in the TMC2660, so the over-temperature detection on the controller chip won't react instantly to an overheating mosfet.
I originally hoped to implement standstill current reduction in firmware, but that turns out to be very difficult to do in a way that is 100% reliable.
Duet 3 will allow higher currents, certainly over 3A and maybe as high as 4A.