Quote Originally Posted by DarkAlchemist View Post
All motors but Z are being ran at max Vref (118 not the normal 128 one would believe) so they get hot enough to blister your hand as X did to me. Since the carriage is ABS I am surprised the motors haven't caused it to sag at the very least.

It appears not a soul knows what Vref should really be except it should not be at full throttle (at least with Marlin using Stepsticks we knew what Vref meant precisely).

My suggestion would be to turn all motors down to 80 (leave Z at 40) and do a nice print and see what happens. If no skipping then after 1 hour feel the motors and if mildly warm 80 was the magic number.

You can do what I did with my I3 and just keep going lower and lower until the motor would skip or lose steps then back it up some. By doing that you will have way cooler motors that will last longer and the ABS plastic parts will love you for it. So, 80 and if that works go 60 and if not then 70, etc... since we have no idea wth the formula is for a Mightyboard.
I guess it's time to reveal my ignorance, to address the Vref adjustment, is that done via the firmware or a POT on the stepper driver etc? Is this something a novice should attempt?

Roger