I’ve seen it suggested on the MakerBot Operator’s group (I forget who…) that Z axis rod wobble can be introduced where the bearings fit on the Z axis rods. This is an interesting possible source of error… and a solution!
It would seem that if the placement of the bearing on the rod can introduce warp, it might be able to slightly counteract warp as well. I’ve gotten my Z axis wobble mostly under control.
As I mentioned, I had installed the Z-axis threaded rods without actually cleaning them first. It wasn’t that bad to undo the caps, pull them out, and clean them. In fact, it was kinda fun.
The process involves covering one end of the threaded rod with electrical tape to protect the threads and your drill, inserting that end into an electrical drill, adding 3-in-1 oil to the rod, and running the drill while holding a paper towel to the threads with a thumbnail. It worked great and went much easier than I thought it would be. I also used this opportunity to lower the threaded rods into the lower section of the MakerBot. I’ll need to make sure they don’t get caught on any wires, but that will be all part of the process of zip tying all of the wires down anyhow.
Since I was going over things I had already done, I went ahead and also tightened up the Y-axis pulley. It’s kind of a pain to adjust once the XY stage is installed, but I happen to have a very small adjustable wrench that was able to reach underneath the XY stage.