After I made my crank handle I realized that it wouldn't work very well on things with the nut on the underside, like my binding frame. So I made an adjustment wheel. If the pointy notches hurt your fingers, see my Customizable Adjustment Wheel Mark 2 with more comfortable grips.

[Edit]For whatever reason, the .stl I originally uploaded was actually an .stl of my crank handle. Sorry about that.[/Edit]

Instructions

Simply measure the nut you want to turn into an adjustment wheel, pick some reasonable measurements for the wheel itself, and print.

I don't actually have a 3D printer yet, but it's simple enough I'm sure it should work fine. Please let me know if there are any problems.