Fig. 181.—A Home-made Switch.
Fig. 182.—Details of Switch.
[Figures 181] and [182] show how to mount the lever and binding-post plates upon the switch base. Pivot lever A with a small screw passed through a hole punched near its end, and through the hole near the folded end of plate C. Fasten plate B with a rug-tack (F) so the lever will come in contact with it. Screw-eyes E form the binding-posts.
Fig. 183.—Detail of Mast.
Fig. 184.—Detail of Pulley.
Fig. 185.—Detail of Boom.
Instead of using a separate base, the switch can be mounted as shown in [Fig. 176], upon the base of
The Derrick. Cut the base about 8 inches wide and 10 inches long (A, [Fig. 176]). The mast (B) is a piece of broom-handle or curtain-pole 16 inches long, and fits loosely in a hole bored in the base. [Figure 183] shows a detail of the mast. The pulley upon its upper end (C) is made of two spool-ends nailed together ([Fig. 184]), and it turns upon the axle D, which slips through holes in the plates E nailed to the end of the mast. The lever F sticks in a hole in the mast, close to the platform. This is used to swing the boom from side to side. Screw-eye G is placed several inches above F to serve the purpose of a pulley to guide the hoisting cables.