Adjustable link

You need to screw things together but need to be able to adjust the distance, here is a solution to that problem.
Customize bolt size, width, length and thickness.
The customiser unfortunately have a bug (it doesn't understand entering the diameter for cylinders, only the radius), a nre version of the same thing can be found here: http://www.thingiverse.com/thing:394679 use that one instead if you want to use the customizer!
Downloading the scad file an using open scad works equally well for both versions.

This version is now modified so it doesn't have the customizer tag, use the linked to item if you want to use the customizer.