I was doing some checking on the machine tonight i was hoping the last night. But i would go to a position and set the XY to zero. Then i would bring Z down and tell it that was Zero by reset Z to zero. Then i would move all axis and tell it to go home. Now the Z axis is higher than home. But when i tell it to go home it would sometimes run the Z axis up before it would go back down. One time i actually jammed the Z axis any reason it would do this? Just want to understand it all.
It does not happen every time?
If an axis is occationally moving in the wrong direction it is usually a sign of a poor / faulty connection on one of the four wires between motor/stepper driver.
If one wire is disconnected there is no “direction” provided by the step sequence. The same pair of coils will cycle ON/OFF and the axis will move the direction of less resistance.
With two pairs running the cycle determine direction, with one pair faulty direction is lost.