Hi,
I try to use a SY42STH47-1684B stepper motor with a standard MakerBot extruder board. As far as I can tell, the SY42STH47-1684B is a tested stepper motor for building a Mendel extruder.
My problem is, that the both DC motor driver chips on the extruder board run very(!) hot after a few seconds. At least 70-100°C after test driving the motor (without filament or something) for 10 or 20 seconds. The motor turns as expected.
The extruder board currently still runs Makerbot Firmware (compiled for stepper motor drive).
Is this normal? Do I something wrong?