Rigidbot Z Wobble Solution

The Rigidbot is a bit of an older printer by now, but I'm sure there are still a few of them out there. Mine suffered from z axis wobble for a long time, many years, but decided to address it recently.

The source of the problem is the manufacturing tolerances and assembly tolerances... hard to get everything perfectly square when you have no adjustment. My X gantry guide rods and lead screw were fighting each other down at the bottom of Z travel. The alignment was off and the aluminum misali