Crank Handle Knob for GasBoy 1200-series rotary hand pumps

This is a printable knob designed for the crank handle of a GasBoy 1230c rotary hand-operated fuel pump. It should work with any 1200-series GasBoy pump as well as in any application where a 5/16-inch axle/bolt is used to retain the knob. This is designed to fit snugly on a partial-thread 5/16x5" bolt when the 1-inch-long thread is fully engaged. It uses standard 5/16 flat washers as end caps, though if you desire a smoother operation it could be easily modified to accept a bearing of your choice. The handle is quite chunky and is designed for operation in all weather, with or without gloves.