Power route plus z axis binding

[brian73]

OK so finally finished the build of my Power route plus and seem to have an issue with the Z axis. It is binding going up. Checked the Allen screws and all seem tight. I have noticed the back plate is rubbing on something but not certain what I have done incorrectly 

I would attache pics but for some reason I can't....... I guess its just one of those days lol

[bonedoc]

did you figure this out.  I just put mine together and found that I needed to have the fixed bearing in the highest possible position.  Once I did  that I did not have anymore issues.