129. Winder. Fig. 70. For winding bolt magnets, this form of winder is very useful. It consists of a "stove bolt," S B, 2 in. long (total length) and 5⁄16 in. in diameter.
Fig. 70.
130. Handle or Crank, H, is made of a stout wire, 4 in. long, bent at the lower end as shown. H is fastened into the slot of S B. To do this the end of H is hammered flat until it will just slip into the slot. It may be soldered there, or be made to fit by expanding it so that it will press out against the sides of the slot. To do this, place S B into a hole in an anvil, or hold it in a vise, being careful not to injure the thread. Place the flattened end of H in the slot, and strike it on top so that it will expand and be pinched in the slot; but do not pound it so hard that you split the bolt head. Three or four good center-punch dents upon the wire over the slot will help to expand it.
131. The Framework is made of wood, the dimensions being shown in Fig. 70. A 5⁄16 hole should be made for S B, the thread of which will stick through about ¼ in. so that the winder-nut, W N, can be turned onto it. W N should be on but 2 or 3 threads of S B. This will leave part of it for the thread of the bolt magnet, and when this and S B meet in center of W N they will bind against each other and hold the bolt tight. The winder can be nailed or screwed at S to the edge of a table or held in a vise.
