John,
I am now sure it is the drives that are over heating. At the point where they fail, and the yellow LED is permanently lit, the drives are quite warm and you can feel the heat radiating from them. They are nowhere near as hot as the steppers. My homebuilt machine has servos driven by Geckos and they, nor the servo motors, even get warm to touch so I was quite surprised just how much heat was generated by the Syil machine.
I don't think it has anything to do with load on the steppers as I have tried switching the machine on and not moving any of the axes and after a time the drives overheat and fault.
Mike |