I use the 2250 drivers set to 2A per drivers spec.
It is weird that the x and y motors stay cool with the same settings but a is getting hot.
Extruder motor I set to 1A as I just don't know the specs. Got some generic mk9 and it did not have any spec sheets included, so I just went ahead and reduced the amperage just in case.
As far as z Plunge, I do reset through LCD controller when machine starts ( and I move my head to desired location first, nozzle just touching the table).
Still, when process starts, head goes down past table first the raised up and tries to print in the air.
I do not have end switches installed.
Overall z is 12". Frame tube over table (center of lower axis tube) is at 8.75"
Maybe I have a moving wrong direction?
How do I switch it backwards? Just flip the plug?
Thank you much for all the work you out into this project!!!
2A is the rated max usually meaning they will want to run almost 100C above ambient if I remember right. I would dial that down to 80% or so and go up from there depending on stepper temps while in use. Dial them all down until they are warm not hot, I know that isn’t an exact number but it does seem to be the best way. Not all the steppers get used the whole time so the percentages will vary.
I’m not sure what could be happening to your z axis you should include some of your beginning gcode, that should so what is going on. How are you generating it?