The equipment of the motor car provides a collector for taking the current from the "third rail" and conveying it to the motor, and a current re-verser which will enable the direction of the car to be reversed. The design of the collector is shown in Figs. 4 and 5. The car should have two of these, one on each side, so that at crossings and other places where it may be necessary to place a section of the third rail on the opposite side of the running rails, there will be no break in the feed of the current.

Model Electric Railway III Equipment And Connectio 313

Figs. 4 and 5.

The collector shoe, A, which bears on the third rail, and the shoe arm, B and C, are made from a single piece of ribbon brass 5" long, §" wide and 1/16" thick, bent as shown in Figs. 4 and 5. This can easily be done by placing it in a vise and bending the turns with a small wrench; a bicycle wrench answering nicely. Care should be used to make the bends in the right direction, and a cardboard model may first be made to serve as a guide. A hole, D, is drilled in the part, B, to receive a small wire nail, the inside end of which is bent over to hold it in position. Another hole is drilled near the end of the part, C, to receive a screw, E. Around the screw, E, is placed a small spring made by bending brass wire around a large wire nail. This spring serves to keep the shoe firmly in contact with the third rail, and yet allows the shoe to give when meeting joints in the track or obstructions. The screw, E, prevents the shoe from dropping down at switches or crossings, and by touching the running rails, making a short circuit. A little experimenting will enable this screw to be rightly adjusted to secure proper contact with the third rail and yet not reach the running rails.

The support, F, is made from a piece of brass 3" long, 1/2" wide and 1-16" thick, bent as shown in Fig. 5. Two holes are drilled at the outer end for small screws which fasten it to the car floor; one hole is drilled on the inner end for the same purpose. Holes, H, are drilled through the sides to receive the nail which serves as a bearing for the shoe arm. A slot is made in the side of the car floor to receive the outer end so that it will be flush with the side of the car floor. When the collector is complete and ready to be attached to the car, an insulated copper wire connection, J, 6" long, is soldered with soft solder to the joint between the parts, B and C, of the arm. The other end of this wire is connected to one of the terminal posts of the motor. Similar wires, K, connect the other terminal of the motor with one of the supports for each pair of car wheels. Use care to see that good contact is secured for these connections.

The current reverser is shown in Fig. 6. A piece of maple or other fine grained wood 3" long, 2" high and 3/8" thick is needed. This, when all complete, is firmly screwed to the car floor. It may be placed at one end of the car, in which case, a slot for the end of the lever, L, is cut in the top of the car body; or it may be placed near the centre of the car and the lever changed through the doors. In the latter case, the wooden piece must be made shorter or slots cut in one end of it for the belt connecting motor and clock work. Five brass machine screws with nuts are required, though ordinary brass screws may be used; also one piece of brass 21/2" long, 3/8" wide and 1-16" thick, and a similar piece 13/8" long. Bore 1/8" holes 1/4" from the lower ends of each piece, and make bends 1/4" above these holes so that the upper parts will be 1/8" away from the wooden support but parallel with it. Bore 1/8" holes in each piece 1" from the lower ends to receive screws holding in place the wooden cross piece, M, which is 13/8" long, 1/2" wide and 1/2" thick, this cross piece being on the outside of the brass strips and the screws put through from the inside. The screws should work easily in the holes so that the lever will not be hard to move.

Model Electric Railway III Equipment And Connectio 314

Fig. 6.

In the piece of wood 1/8" from the bottom side and §" each side the centre, bore holes to receive tightly the machine screws, A and B, Fig. 6, which are put through the lower holes in the brass strips. In the centre and 3/8"from the upper edge, put another machine screw, D, and 7/8" to each side of it and " from the upper edge put the two remaining screws, C and E. Small nails, N, are driven into the wood to keep the lever from being pushed over too far to either side. After the screws are in position, file the heads a little to make them flat, thus securing a better contact. When this has been done and the lever is in the position shown in Fig. 6, the screws, A C and B D, are connected. If the lever be pushed to the other side, the screws, A D and B E are connected, thus reversing the polarity of the current at the brushes. This result is secured by connecting this switch with the wires leading to the brushes of the motor. An examination of the motor will show that wires are connected to the brushes, one leading to a terminal post and the other to the field winding. Carefully cut these wires, leaving enough wire for new connections on each side of the cuts.

In some forms of motors these cuts can be made several inches from the brushes. Connect these ends with insulated wire, soldering the joints with soft solder, to the switch as follows: A wire from the brush end of one brush wire is connected to screw, D; the other end of same brush wire being connected to screw, B. Connect the brush end of the other brush wire by a branched wire to screws, C and E, and the remaining end of the brush wire to screw, A. The action of the switch should be quite evident.

The current should be supplied by some form of closed circuit battery, a bi-chromate probably being the most practicable to the majority of readers. Descriptions for making this form of battery were given in the December and June numbers of this magazine. If circumstances do not permit of the making of a battery, Leclanche cells with cylindrical zincs may be used, replacing the sal-ammoniac with bi-chromate of potash solution and amalgamating the zincs as directed in the descriptions above mentioned. Several cells will be required, the number depending upon the weight and construction of the motor car and train to be moved. The several cells are connected in series or series-multiple as may be found by experiment to produce the best results with the motor used in the car.

The battery is connected to the rails with insulated copper wire, No. 12 or 14 guage, the zinc pole being connected to the third rail and the carbon pole to each of the running rails. If a considerable length of track is used, two or more connections with the battery are desirable to reduce the resistance of the rails. All rail connections should be made with soft solder, a soldering fluid or paste being used to enable this to be easily done. A switch in one of the battery feed wires for shutting off the current will be found desirable. This can easily be made, with a small strip of brass and two brass screws, using a small block of wood for a base. The zincs should always be taken from the above battery when not in use, as the zinc is consumed while in the solution, whether any current is flowing or not.

The way to make additional equipment for this simple railway, will readily suggest itself to the reader of these chapters.