I think I have found a quick and easy way to make the base/basic non upgraded K8200 print better in the Z axis.
It’s all to do with the nut on the side of the arm.
I was going to put a new Z threaded rod in when I was taking out the old one and saw a problem.
The nut is slightly loose inside the housing casing causing the arm to stagger/lift/roll every turn.
I loosened off the top 2 screws that hold the nut in place.
Without removing the Z axis nut, I then put a piece of thin card cut in a thin strip about the size of the nut height (something like a business card) around the head so it holds it tightly in place and it doesn’t slop around.
I also made 3 ‘gaskets’ with a hole in the middle that fit on top the nut so it doesn’t interfere with the Z axis rod. This stops it from moving up and down when the top is re-screwed on.
Put the 2 bolts and nuts back on and tighten. You should not have to re-align as the nut is still in it’s original position, but if you do it is only going to be about 1mm if so.
It helped me get a lot better and smoother prints out of my printer.
I hope this helps others too.
John from Western Australia.