I just found this video of a nice honey house that runs what looks like 2 Dadant 20 framers. What caught my eye in the video is the "wobble" we have been discussing, and it shows it here at around the 2:10 mark. You can see the clearance between the reel and the wall and how it fluctuates to some degree. Mine does this as well, but I do not believe it is "unbalanced" as it runs smoothly. I think if you liken it to a car wheel, if it is unbalanced they simply add weights to it to get them to run smoothly. I assume when they assemble these things that any anomaly in the balance is accounted for and corrected.