moved to Stepper Driver Adjustment no need for this anymore
The trim pots may need to be adjusted for stepper current. The ideal setting is above the point at which the stepper motors are too weak to complete a movement, and below the point where the driver enters thermal shutdown (a very temporary interruption of movement until the driver cools and resumes powering the stepper, which results in another thermal shutdown). The video above shows the three states - over-powered, under-powered, and properly adjusted. Begin a sample print at 100% speed and turn one axis clockwise until the stepper exhibits the under-powered behavior of missing steps. Then turn the pot counterclockwise until the stepper exhibits proper movement. If you reach the point of thermal shutdown before finding an ideal position, check for binding in the movement of that axis.