Zstep/mm incorrect in Firmware

[ggrshelton]

Geeetech Aluminum Prusa I3 A Pro 3D printer. When I program the Z axis to raise 10mm on the control box, the Z axis raises about 64mm. 6.4 times greater than the 10 mm requested. The Zstep/mm is set at 2560 in the firmware. 2560 divided by 6.4 yields a Zstep/mm of 400. I either need corrected firmware and instruction on how to install it, or I need a replacement control box with Zstep/mm = 400 in the firmware. At 0.2 per click of the adjustment knob, it takes me almost 4 minutes of continuous rotation to adjust from 2560 down to 400. Maybe my math is wrong and the number is not 400, but 2560 is definitely not the correct Zstep/mm value for this printer.

[bang]

400 is the right value,actually you can modify it in the firmware...
Remember to "Save memory" after you modify it on LCD panel.

[ggrshelton]

Now that I've changed and saved the Zstep/mm from 2560 to 400, the motion distance is corrected. However the Z axis moves much slower when homing. What should the other Z axis settings be set at? Currently, Vz Jerk = +0.4, Vmax Z = 2, and Amax Z = 20.