Bench-mounted clamp holds up its end of the deal

Having worked for years as a draftsman and woodworker, I often wish for an extra hand during project assembly, especially when working with large vertical pieces. I've found it a big help to mount a shop-made clamp like this one to my workbench. (I used bench dogs, but screws will work if your bench lacks dog holes.)

Unlike a typical bench vise, project parts held in this clamp still rest on the benchtop, making it easy to keep parts parallel during assembly. And you can build it using only 2x4 stock, a couple of carriage bolts, and a pair of star knobs.
—Tony LoRusso, Wolcott, Conn.