Geeetech Z-Axis Improvement

This is not the definitive solution to Z-Axis wobble, but does offer some additional improvement.

The main improvement was the green component shown in the photo and there are several versions of that in Thingiverse (such as thing:808509).

However, the Z axis can still float a little during up/down transitions as it relies on the force of gravity exceeding the force of friction. By adding a nut and a spring on both left and right Z-Axis threaded rods, there is constant downward pressure on the thread and less Z-Axis height 'wobble'.

The nut is a standard 8mm, As for the springs, the ones I chose are fairly stiff. The yellow blocks holding the nut cannot rotate as they ride against the X-axis frame.

The blocks were printed on my 3D printer and therefore show the wobble effect before the fix was installed.