“Inspired by Speedy777’s Pump Drill link, which was inspired by Performance 3D’s drill), this slightly beefier version features an adjustable chuck that can handle bits from 5mm (3/16”) down to 1.5mm (1/16”). The end of the bit seats in the conical shaped chuck cavity, and the flexy fingers at the tip grab further up the shank. You get 2 full rotations per stroke for fast drilling. It also works as a pin vise for holding needle files.”