Sash Clamp

This is a 3d printable sash clamp. Long clamps are expensive, this is a low cost alternative, the length is limited only by the length of the wood board used as the bar. The width of the board to use is 3/4" or 19mm. This clamp uses 1/2" or 12mm bolt and nut to provide the clamping force. The parts are mounted to the board using 5/16" or 8mm bolts.

Updated: there is now a simple method to attach the foot without having to grind the bolt. an inner foot threads onto the bolt, and an outer one just clicks over the inner. If need be the inner one can be glued to the bolt, but mine hasn't loosened yet, so it probably isn't necessary.
Old method:
The foot should be retained to the clamping bolt. first by grinding a groove to the root of the threads, about 1/2' or 12mm from the end of the bolt. Retention is provided by two #4-40 or 3mm bolts, clevis pins, or even cable ties.

Long bolts threaded fully are not always easy to find. I used a length of threaded rod, and locktite