q Amateur - 

 Electrician 



^And Wireless Operator 



Applying Insulation to Splices 

 Made in Electric Wires 



TO comply with the rules of the American 

 Institute of Electrical Engineers, it is 

 necessary to apply a rubber coating over a 

 soldered joint in a wire. One of the best 

 methods of doing this is to lay on the 

 rubber over the splice before it begins to 

 cool from the soldering operation. The 

 thickness of the coating depends on the 

 amount of voltage carried in the line. 

 Cover the rub.ber insulation immediately 

 with friction tape, drawing it tight, while 

 putting on a sufficient number of layers to 

 stand the wear. 



To make a neat covering, cut the friction 

 tape into narrow strips, less than */£ in. 

 wide, and a smoother joint will be the 

 result after the wrapping. If this is done 

 neatly and drawn tight enough there will be 

 a noticeable bulge in the joint. This can 

 be easily wrapped with a cord — silk if the 

 case calls for it — then given a coat of 

 shellac. If the proper color cord or silk is 

 selected a joint that cannot be easily 

 detected results. 



A Simple and Easily Made Electric 

 Battery Motor 



A SIMPLE and easily made motor that 

 will run at high speed with two or 

 three cells of dry battery, or on an alternat- 

 ing current with a transformer, is shown in 

 the illustration. While this motor can be 

 made in any size that will appeal to the 

 experimenter, only one dimensioned draw- 

 ing is given. Procure two hexagon-head 

 bolts, A, 2Y2 in. long and \i in. in 

 diameter under the head, also some thin 

 hard fiber tubing l /i in. inside diameter 

 to slip over the bolts. Cut two pieces B, 

 each 2 in. long, and fit on heads or washers, 

 C, about J/g in. in diameter, leaving J4 in. 

 of the tubing projecting at the threaded 

 end. This forms the spools for the magnets. 



Wind the spools with No. 22 or No. 24 

 magnet wire in the usual manner having 

 the inside as well as the outside ends come 

 out at the back end of the magnet. 



The soft iron standard D is about 3 in. 

 high. V2 m - wide and 3^8 i n - thick and bent 

 L-shaped at the lower end to form a foot by 

 which it is screwed to the base. In the 

 standard are drilled three holes. Two of 

 these are of the same size to allow the ends 

 of the bolts or magnet core to enter and 

 project on the outside for the nuts, which 

 hold the back ends of the coils in position. 

 The third hole is located centrally between 



Universal motor that will run on a battery 

 current or reduced alternating current 



the other two to accommodate the shaft. 

 The same number of holes and in the same 

 position must be drilled in the brass yoke 

 for supporting the front ends of the 

 magnets and the front bearing. This brass 

 yoke may be a flat strip about ^ in. 

 wide and of a length to cover the front 

 ends of the coils. When the bolts are put 

 through the magnets the protruding ends 

 of the fiber tube will butt up against the 

 back standard and all parts will be held 

 securely in place. 



The armature poles F consist of soft 

 iron buttons about Y* in. in diameter and }/i 

 in. thick, connected by a strip of brass % 

 in. wide, having a hub # in the center for 



147 



