Swapped out the Brass Anti-Backlash Nuts on the CR10S Pro with POM nuts

I've been trying to tune the Z-Axis due to some fine lines that show up on larger prints, which I'm sure are z-wobble related.  They are not enough to really bother me normally, but I am thinking about re-printing the doors on my enclosure with a slightly newer design, and the prints will be tall and take a good deal of time, so I want to get them right.  Since I was gonna re-work the Z anyway, I decided to pick up some POM anti-backlash nuts which I would have bought had I known they were a thing, before I installed the brass ones.  The CR10S Pro requires the 8mm version which has 2mm pitch (goes up 2mm with each full rotation) and 4 starts (which are the number of starting threads if you look at the top of the leadscrew - a normal screw has one start).  POM has better qualities than brass for this type of thing, and should need less lubrication.  Similarly to the brass ones, I had to file a bit from one side of the nut that installs on the ribbon cable side, and used a nut and a lock nut on each screw to secure them.  The screws that hold these should not be tight, but they also cannot be loose, so it's a bit of a fiddly thing, and the lock nut should lock against the regular nut (it would go spring washer, regular nut and then lock nut).  I lost a couple of the spring washers though so not all mine have them.

I also went back over the Z-setup following the process outlined in this video.  I also found a few things during teardown which may have been contributing, specifically the old brass nuts may have been too tight and the top left bearing guide had to be scootched over just a bit to align with the leadscrew better.

I still need to test this, and will update with some pics once it is tested.

Update 7/18/2020: They work great, and I can see a slight improvement in the print quality, would definitely get these over the brass ones.