Prusa i3 - Z Axis motor problem

Whenever I home my Z axis, the motors just start making a sound without moving. Which setting should I adjust to make this work? Here is what is happening. Sorry for the bad video quality, but it should get the point across.

M501:
echo:Hardcoded Default Settings Loaded
echo: Steps per unit:
echo: M92 X99.67 Y98.43 Z4000.00 E836.00
echo:Maximum feedrates (mm/s):
echo: M203 X500.00 Y500.00 Z5.00 E25.00
echo:Maximum Acceleration (mm/s2):
echo: M201 X9000 Y9000 Z100 E10000
echo:Acceleration: S=acceleration, T=retract acceleration
echo: M204 S3000.00 T3000.00
echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum XY jerk (mm/s), Z=maximum Z jerk (mm/s), E=maximum E jerk (mm/s)
echo: M205 S0.00 T0.00 B20000 X20.00 Z0.40 E5.00
echo:Home offset (mm):
echo: M206 X0.00 Y0.00 Z0.00
echo: PID settings:
echo: M301 P22.20 I1.08 D114.00

Edited 1 time(s). Last edit at 11/11/2014 01:56AM by quillford.

It looks like your Z feedrate might be too high. Try lowering your Z max feedrate to 3 (mm/s). I had the exact same problem as you, and just lowering the feedrate (and as such the speed) fixed it.

Yes I agreee with solomondg, I experienced that as well some time ago. Start by reducing z axis speed by 50% in firmware and for the manual moves in pronterface.

Quote
solomondg
It looks like your Z feedrate might be too high. Try lowering your Z max feedrate to 3 (mm/s). I had the exact same problem as you, and just lowering the feedrate (and as such the speed) fixed it.

It seems to have resolved the issue. Thanks