Inspired by DaleDunn's elegant solution for z wobble on the Prusa (Thing 20147), I designed a version for the Ord Bot Hadron. This should also work on the Quantum assuming there's enough clearance.
There are two versions: One uses the z nuts that came with the Ord Bot Kit and the other uses M8 nuts. A plastic washer might be needed between the two parts to minimize change in z height due to bent threaded rods.
Update: The upper piece was too long and it was hitting the z endstop switch on the gantry. So, I deleted the bad files and uploaded the modified files.
Photo shows comparison of 20mm square x 100 mm tall single wall print with the wobble suppressor (left) and without (right). There was significant z screw wobble with rigid metal Ord Bot z coupler used in this test.
The remaining z wobble was due to friction between one of the z nut holders and the post. After sanding it down to allow them to slide freely, z wobble was completely eliminated as shown on the photo.
Print the test stl file first to make sure that the slot on the z nut holder fits snugly around the post on the mating gantry support reduce z backlash. If needed, you should be able to tweak the clearance using the extrusion multiplier parameter slic3r.
The mounting holes in the z nut holder are meant to be tapped with M5 threads.