Battery Power Cars - Evans Boxcar | Show Menu |
by Paul Norton
INTRODUCTION
Aristo-Craft Plug and Play locomotives have MU plugs on each end, and a switch to change between track power and battery power. This article details how to build an Evans power boxcar to take advantage of those plugs. A power car is simply a battery car with a receiver added for on-board radio control.
This power car utilizes two, Aristo-Craft, lithium-ion battery packs and is designed to power and control big locomotives like a Dash 9 or SD-70 MAC.
As this is an enclosed car, the battery packs will be charged on-board using two plugs. At least one Aristo-Craft, lithium-ion battery pack charger will be required, but two are recommended so that charging can be completed within four hours. A Four Pole Double Throw (4PDT) switch will be used to toggle the battery packs between the charging plugs and the receiver. The plug sets and switch are both available from All Electronics under catalog numbers CON-240 and STS-71 respectively.
An Aristo-Craft, 27 MHz, Train Engineer (TE) set will be used to provide the radio control, as it can handle the power requirements of large locomotives or multiple lash-ups. If your TE transmitter came with a short rubber antenna, call Aristo-Craft and request a replacement telescoping antenna. The chrome telescoping antenna will dramatically increase radio range.
In order to further improve radio range, the long wire antenna on the receiver will be replaced with an Azarr, micro-lite antenna. With the telescoping antenna on the transmitter and the micro-lite antenna on the receiver, reliable and responsive radio range of greater than 100 feet is expected. The M-27-L antenna is available from E Cubed R/C.
A boxcar is needed to provide the necessary height for the antenna to function properly.
REMOVING THE CAR BODY
Remove the 6 screws indicated with yellow from the bottom of the car. Lift the car body from the frame. Fasten the screws back in the car body, so they do not get lost, and set it aside for now.
POWER CAR SWITCH
On the side of the frame WITHOUT the brake line, drill a 1/2 inch hole at the spot marked with the yellow X for the Four Pole Double Throw (4PDT) switch.
Install the power car switch so it toggles forward and rearward. Stick a Charge label on one side of the switch and a Run label on the other as shown.
Check to ensure the switch is in the center off position.
BATTERY PACK CHARGING PLUGS
CAUTION: The 2-pin plug sets sold by All Electronics are not always colour coded the same as Aristo-Craft plug sets. If the colour coding is not the same as on the lithium-ion battery pack and charger, just click on the following link to see how to change the AE Plug Set Wiring so that proper polarity is maintained.
The female half of an All Electronic plug set has the same connector as the Aristo-Craft, lithium-ion battery pack. Trim the wings off two AE female connectors.
Drill two, 1/8th inch holes in the frame at the spots marked with the red Xs for the battery pack charging plugs. Pass the wires of a plug through one of the small holes, and hot glue the connector to the bottom of the frame. Repeat the process for the other plug.
Flip the frame over and hot glue around the wires. Cut the wires to a length that will easily reach the power car switch.
Strip 3/16ths of an inch of insulation off the ends of the four wires. Solder or crimp a number 6 loop terminal on the end of each. The loop terminals are available from All Electronics under catalog number 8106.
Fasten the loop terminals under the screws on the edge of the 4PDT switch as shown in the following diagram. The colour coding of the wires from the center of the car to the edge should be: red, black, red, black.
That completes the installation and wiring of the lithium-ion battery pack charging plugs.
LITHIUM-ION BATTERY PACKS
Drill four, 3/16th inch holes in rear end of the frame as shown in the following picture. Pass long cable ties through the holes taking car not to damage the frame details.
Use Velcro dots to fasten the lithium-ion battery packs between the four holes as shown. Secure the packs using the cable ties.
CAUTION: Take care when handling the battery pack wires to ensure they do not touch each other, or both make contact with any metal object such as a wire cutter, stripper or screwdriver. DO NOT CUT BOTH BATTERY PACK WIRES AT THE SAME TIME.
Cut the red wire on a battery pack about 1/4 inch from its plastic connector. Solder or crimp a number 6 loop terminal to the wire. Repeat the process for each of the other three battery packs wires.
Fasten the battery pack loop terminals under the screws in the center column of the 4PDT switch as shown in the following diagram. The colour coding of the wires from the center of the car to the edge should be: red, black, red, black.
That completes the installation and wiring of the lithium-ion battery packs.
27 MHZ RECEIVER
Turn the receiver case of the 27 MHz receiver over and remove the four screws at the corners. Open the case and remove the circuit board. If it sticks, remove the fuse. Put the case back together, install the four screws, and put it back in the box it came in.
Place the circuit board or a template on the front end of the frame against the posts as shown. Drill 3/32 inch holes in the floor using the holes in the corners of the receiver or template as a guide. Tap the holes with a 4-40 screw.
Turn the receiver over and glue a 1/4 inch long spacer around the hole at each corner. The nylon spacers are available from All Electronics under catalog # SP-42.
Unsolder the long wire antenna from the circuit board, and replace it with an M-27-L micro lite antenna.
Fasten the receiver to the floor of the car with 1/2 inch 4-40 screws. Shape the antenna so it will follow the roof line on the inside of the boxcar.
Cut the heavy, red and black, power input wires of the receiver to a length that will easily reach the power car switch. Solder or crimp a number 6 loop terminal to the black wire only.
Cut a piece about two inches long from the extra red and black wires cut from the receiver. Split the red and black wires apart, and set the small piece of red wire aside for now. Install number 6 loop terminals on both ends of the black wire. This wire will act as jumper between two screws on the switch.
Place the loop terminal of the black wire from the receiver and one of the loop terminals on the black jumper wire flat against each other. Fasten the loops under the screw on the edge of the switch as shown in the following diagram. Fasten the loop terminal on the other end of the black jumper wire to the switch as shown. The switch can be moved 1/8 of a turn to access the screw behind the plastic post on the floor of the car.
Bend the terminals slightly so the black jumper and receiver wires are about 30 degrees away from the switch. This will make it easier to install the diodes in the next step.
Two, 3 amp, 40 volt, Schottsky diodes are a safety device to block power from passing from one battery pack to another. The power can only flow from battery packs through the diodes to the receiver. The diodes are polarity sensitive and have a band around the end with the negative lead. The diodes are available from All Electronics under catalog # 1N5822S.
Straighten the positive leads of two diodes. Strip a length of insulation off the small piece of red wire split from the black jumper. Cut two pieces exactly 7/16ths long from the insulation. Slip a piece of the insulation on the positive lead of each of the diodes.
Slip a number 6 loop terminal over the end of the positive lead of each the diode and solder or crimp them in place.
Fasten the loop terminals under the screws on the edge of the 4PDT switch so the negative leads overlap as shown in the following diagram. The switch can be moved 1/8 of a turn to access the screw behind the plastic post on the floor of the car. Solder the red wire from receiver to the overlapping leads.
Cover the negative leads of the diodes and the solder joint with insulating tape.
Check to ensure ALL the wires on the switch from the center of the car to the edge are colour coded: red, black, red, black.
That completes the wiring of the power car switch.
CHARGING THE BATTERY PACKS
If the battery packs have not been charged, with the power car switch in the center off position, plug in each of the battery chargers. Plug the chargers into a wall outlet and toggle the switch forward. When the switch is toggled forward, each of the battery packs is connected independently to its charger.
The chargers will take about four hours to charge the lithium-ion battery packs completely. When complete, toggle the switch to the center off position and remove the chargers.
PROGRAMMING THE 27 MHZ RECEIVER
The receiver has a small power switch next to the fuse. Turn it on by sliding it toward the heat sink. Slide the small switch on the back of the circuit board toward the red LED, its linear power position. If this switch is left in the PWC position, the momentum and soft reverse features will not work.
Programming momentum prevents sudden starts or stops which could damage the gears in a heavy locomotive, especially if it is hauling a long train. The soft reverse feature can be used when switching cars. When the reverse button is pushed the locomotive will slow to a stop, pause while a car is coupled or uncoupled, change directions, and gradually resume speed in the other direction.
When the power car switch on the bottom of the frame is toggled rearward, the battery packs are connected in parallel through the diodes and jumper wire to power the receiver.
The red LED on the back of the circuit board should light up and stay on. If the red LED goes on and then fades out, return the lithium-ion battery packs to Aristo-Craft for a replacement.
Link and program the transmitter and receiver as detailed in the manual that came with them. If the transmitter is used with other receivers, using the first two digits of the power car number to program the frequency and channel numbers is an easy way to remember them.
After programming the TE, leave the small TE power switch on but return the power car switch on the bottom of the frame to the center off position. The red LED on the back of the circuit board should go out.
POWER CAR PLUG
Drill a 1/8th inch hole in the center of the front end of the car body between the first two bottom ribs. The front end of the car has no brake wheel. Slide a 1/2 inch length of shrink wrap down the wires of the female half of an AE plug set until it is against the connector. Slip the wires through the hole and pull them until the shrink wrap and connector are snug.
About 2 inches inside from the car wall, hold the wires together and place a glob of hot glue on them. This will act as stress relief should the power car and locomotive become uncoupled during operation. Two inches of slack in the plug wires however, does make it easier to connect the plug before the power car and locomotive are coupled together. The excess wire can be pushed back into the power car after coupling.
Some owners also remove the locking tab from the connectors on their locomotives. If the power car and locomotive become uncoupled during operation, the connectors will slip apart and the locomotive will stop. Alternatively, the ridge on the power car connector could be filed flat and the locomotive connectors left untouched.
Solder and shrink wrap a length of wire to each of the plug wires. The wires should be long enough to pass under the receiver and reach the output screws on the receiver when the car body is set beside the frame. Solder or crimp number 6 loop terminals to the ends of the wires.
Set the car body beside the frame. Slip the wires of the power car plug under the circuit board and fasten their loop terminals under the output screws on the receiver. This is the one time that polarity does not matter as it will change with each change of direction.
That completes the wiring of the power car.
REASSEMBLING THE CAR
Remove the six screws from the car body. Tuck any excess power plug wiring under the receiver. Place the car body back on the frame taking care not to disturb the antenna. Do not insert the screws yet.
CAUTION: Always ensure the power car switch is in the CENTER OFF position before connecting or unplugging a locomotive. It is not unusual for a locomotive to jump slightly when the power car switch is toggled to power the receiver.
Connect a Plug and Play locomotive to the power car. Toggle the power car switch rearward, and test the power car for function and range.
If you have a transmitter that has a dedicated button for each direction, you may find the arrows on the buttons and the direction of the train are mismatched. If so, just reverse the positions of the power car plug wires under the output screws of the receiver.
If everything functions properly, toggle the power car switch to the center off position, unplug the locomotive, and fasten the car body to the frame with the six screws.
CONGRATULATIONS! You now have a power car that can let you enjoy all the benefits of a battery powered and radio controlled locomotive or two.
Comment on this Page
Last Modified 8/25/08 3:17 PM