Reprap Z-Axis force down nut.
Description
This thing will force down the Z-Axis of a reprap pursa.
Instructions
As photos~~
License
Reprap Z-Axis force down nut. by below_cho is licensed under the Attribution - Share Alike - Creative Commons license.

I am using RepRap as a CNC Router also. The Z-axis will going upward and download frequently. The original design of Z-axis only forced up and using spring in downward direction. The Z-axis value does not match the real value and the speed of downward have no control at all. This "Thing" will force the Z-axis downward and prevent the Z-axis going down too quick.