I have the standard mini mill most guys have. There is a seriously fine line between no play in the dovetails/gibs, and too tight to operate. Which is especially becoming an issue now that I'm trying to build a power feed with a 12v motor. It just won't run sometimes. Also, when I get near the end of the travel on either side, it really tightens up... so, uneven grind, and poor quality gibs? Suggestions? It makes for poor cuts when I have to crank the wheel if I'm at the end of the travel.