Small quick release clamp

I needed a small clamp to hold printed circuit boards during milling on my home built CNC machine. Screw-type clamps would have to be used upside down and interfere with the head, while spring-type (or clothespin-like) clamps exterted either too much or too little pressure and were prone to bending my PCBs a bit, even on a backer board.

Then I found AndyGadget's elegant bungee-based vise on Instructables:http://www.instructables.com/id/Quick-Clamp-Release-Vice-Vise/ and realized I could use h