A piece of steel tubing (S), No. 10 gage, ¾ inch in diameter, 11½ inches long, will be required for the mandrel. Get a blacksmith, if a machine shop is not convenient, to put a fixed center (1) in one end, and a removable centering member (2) in the other end.
On this mandrel place a collar (3), held by a set screw, and alongside of it a pair of pulleys, each 1½ inches wide, one of them, being, say, 2 inches in diameter, and the other 3 inches. This mandrel is held in position by means of the posts of the frame which carry the split journal bearings. This form of bearing will make a durable lathe, free from chattering, as the bolts can be used for tightening the mandrel whenever they wear.
Fig. 244. Mandrel.
The center point (1) is designed to rest against a metal plate (4) bolted to the wooden post, as shown in the large drawing.