First, a disclaimer: I'm going to talk a lot about something that I will mostly call Z wobble in this post. I know there are folks in the RepRap community with strong ideas about what Z wobble really means as opposed to Z ribbing or various other artifacts and anomalies found on the vertical sides of printed walls, so please forgive me if I'm using the language incorrectly. What I will be talking about is the side to side shifting of layers caused (at least in part) by the threaded rods pushing Read more [...] printrbot GO – couplers, couplers, couplers
First, a disclaimer: I'm going to talk a lot about something that I will mostly call Z wobble in this post. I know there are folks in the RepRap community with strong ideas about what Z wobble really means as opposed to Z ribbing or various other artifacts and anomalies found on the vertical sides of printed walls, so please forgive me if I'm using the language incorrectly. What I will be talking about is the side to side shifting of layers caused (at least in part) by the threaded rods pushing Read more [...] 
So after my last round of functional but peripheral upgrades (getting all the tools into handy locations) I decided it was time to focus some time and effort on the printing performance of the bot (an idea that felt almost novel after all of the aesthetic mods I'd otherwise been consumed by recently).
It was clear to me that the motion in the Z direction could use some refinement because the x-axis carriage seemed to wobble back and forth a little bit when raising or lowering the extruder manually.