Originally Posted by
huh2
Built a CNC machine recently using (4) 3.5A stepper motors (57BYGH433-06BS), a Mean Well SE-600-48 power supply and a G540 (REV8). The motors, G540 and serial cables a purchased as an electronics kit. I had maybe 30 minutes of cutting time (wood) using an old laptop as the controller and a trial version of Mach 3. The laptop proved to be too old, so it was replaced with a desktop. In addition, the motors I had connected to a 12' and 15' DB9 cable would get extremely warm whereas the other two motors (connected to 6' cables) would get warm at most.
So I've replaced the laptop and the (2) longer serial cables with replacements and the motor overheating problem was fixed. My new serial cables are clearly marked 28 gauge- the old cables are not marked but they feel 50% or so thicker than the new cables. After about 2 minutes of use, I heard a pop followed by the smell of burning silicone. I unplugged the power supply and let it sit for a few minutes. Presuming everything was dead, I plugged the power supply back in and was surprised that the green ready led illuminated on the G540. Shortly after plugging it back in and moving some axis, I heard another pop followed by more silicon burning and again unplugged the power supply.
I've since shipped the G540 back to Gecko for analysis to see what happened. Before sending it in, I took the metal cover off and discovered two of the chips were burned- one was for my X axis and the other for Z. Maybe it was pure coincidence, but these were the two axis connected via my 28ga serial cables to the stepper motors. The Gecko tech support said my 28ga serial cable was clearly undersized, but did not imagine that was the reason my G540 burned. He said it was much more likely that my Mean Well power supply output more than the maximum 67V (roughly) required to burn the internal chips.
My question then- anyone have any other thoughts on this? Should I replace the Mean Well power supply with a better one? If so, what would you suggest? I've seen on other posts in the forum and online that suggest this was a good power supply. Or, could I have cooled the drive with the undersized wires? V=IR and my current should have been roughly the same, so if my resistance went up (22ga to 28ga wire) then my voltage would follow. The motors stayed warm to the tough (80F maybe) with my cables, so I do not currently have a resistor between the drive and the motors. I bought the 28 gauge serial cables from showmecables.com. They've always had good products in the past and other than a thin gauge wire, I think these cables are good quality. Looking to fix the problem so I don't burn another G540.
TLDR: burned my G540, waiting for diagnosis from Gecko- either bad power supply, bad DB9 cables or both to blame?!?
Thanks in advance-