These are calibrated (for my printer)
Photo with ruler is to show how off center it was before the print.
I would not recommend restraining z-rod on more than two points.
If You want top and bottom stabilization, You could make the nut "free" with this model: https://www.thingiverse.com/thing:5137480
Category: 3D Printer PartsThe author hasn't provided the model origin yet.