Why do my stepper runs hot? is this normal or what should be the normal temperature?
Unfortunately my IR thermometer can only measure max 42.5 celsius, beyond that it just displays HI. I cannot touch the stepper longer than maybe 5seconds
specs:
mpcnc primo
rambo 1.4
nema17 48oz stepper motor
5A power supply
The Rambo board has built-in stepper drivers (A4982), so there is no way to install external stepper drivers for this board. The primary way to run steppers cooler is to reduce the current. Reducing the current will reduce the torque of the motors, so you may have to be less aggressive with cutting parameters such as feedrate and depth of cut. The usual way I see on this form to adjust the current for the Rambo board is to change the values in the following line in configuration_adv.h and reflash the board.
Using and M907 g-code to set the motor current has been suggest on this forum and should work. If you use a M907, you may have to execute an M500 to save that setting. If you’ve saved the setting, then changes directly in the firmware such as modifying the line I show above will be ignored until a factory reset (M502) is executed.
Note that if you purchased your steppers from V1, there are a lot of people running these steppers with the default current settings with no issues.
Also cooling fans for the steppers have been mentioned on this forum. A quick search of Thingiverse yielded this cooling fan solution, and there may be others.
Edit to add: I’m not an expert, but I don’t believe either of these external drivers will help with running the steppers cooler (even if you could hook them up), and these drivers have a lot less granularity with respect to current settings, so you may even have to run them at a bit higher current to get adequate torque. There are some drivers with advanced electronics/settings such as the newer TMC drivers that may have settings that will run steppers cooler, but I think that even then that you will sacrifice some torque.