Sometimes you need to clamp parts that are out of reach of the throat depth of standard clamps. Here’s a design for a long-reach clamp that can be made from 2×4 lumber, 3⁄4” plywood or solid-wood scraps, some readily available hardware, an F-style clamp and golf balls!
The 2×4 lumber is used to make the fixed arm and the adjustable pivot arm. The length of these arms should suit the present and future needs for this clamp. The fixed arm is glued and screwed to the pivot arm frame. The pivot arm is positioned by using a carriage bolt, washer and wing nut in the holes on the pivot-arm frame to accommodate the glue-up assembly thickness as required.
The golf balls are fastened to the arms by using a Forstner bit to drill 1 5⁄8“-diameter x 3⁄4“-deep recessed holes in the arms. Press-fit the ball into the recess with a vise or clamp – no glue required.
The golf balls concentrate the clamping force, their spherical shape allows clamping on tapered surfaces if required and the resiliency of the golf ball surface acts as a clamp pad. –John Cusimano