Gauge, Woodworking

Description

A speed gauge for a lathe of brass and steel. A fixed steel shaft (tapered) is secured to a brass housing with a rotating face disk. Beyond this brass assembly, another steel shaft, this one turns, is secured inside the housing, apparently to a worm gear that drives the rotation of the face disk which has 20 divisions on its circumference, one of which has a steel index pin. Five rotations of the movable shaft moves this index 1/20 of the circumference so 100 rotations will move the index through 360 degrees of rotation. By timing this rotation, the lathe speed can be calculated.