Much to learn.
Originally, the CNC was built to be run on a Mach version called MaxPath42 but I installed Mach3 instead. The machine has never been used to do a job as I was learning to understand the processes. I got as far as setting up the configs, motor tuning, jogging, setting Soft Limits, loading up G Code and "Cycle Start' dry runs in Mach3. It was then that the TIP120 burnt out ......smoke galore. The X Channel had only 3 out of 4 TIP120 installed as the 4th one was loose in the circuitry box. We installed both the loose and a replacement TIP120, tried again and after some 4 hours the same thing happened ..... again plenty of burning plastic, with a very hot X axis motor. The Y and Z channels and motors were fine.
The machine jogged at what to me was a good speed, but when in 'Cycle Start' mode, at an absolute snail's pace.
I have emailed Dave from Lin Engineering to see if the readings are within specs and for more info on motor characteristics with this wiring configuration; I expect an answer hopefully by tomorrow. It'll be interesting to see if the motors are functioning within specs.
So what I understand you are telling me is that with these readings, the motor would draw a current that can not be met by the circuitry without causing some damage to the TIP120 unless the pulse length is controlled. Would that be a circuitry function or an original setting in the MaxPath42 config, which I may not have picked up in the Mach3 settings? If circuitry, no wonder MaxNC went bust.
Heat build up could be a problem with temps here in the good land of Oz reaching the high 30s Celsius, so opening the box an applying more airflow can be arranged.
Limiting or reducing speed further than it already is in 'Cycle Start' mode would maintain a snail's pace or bring it to a virtual stand still. This issue may be related though to the issue TPS has just raised yesterday re the Motor settings not being 'real'. Could we go into that further, TPS?
I would prefer to wait with the trial run till I've received all info, just in case I blow the A Channel now used as the new X Channel up.