Bachmann Spectrum 55 Ton 3 Truck Shay

Bachmann “Spectrum” 55 Ton 3 Truck Shay.

Description;
Bachmann “Spectrum” 55 Ton 3 Truck Shay converted from track power to battery remote control using the electrical components listed below.
Schematic Diagrams of the electrical connections and Pictures of the install are included below.

Electronic Components; 

Motor Drive

     • Pololu 18V15 Simple High Power Motor Controller controls the three (3) motors which are wired together in parallel
    • The Motor Controller Battery Eliminator Circuit is configured to supply 5V for the Rx.
 Battery

 • 1 x 14.4V 4S2P 18650 Li-ion battery, in the tender to give a nominal 14.8V and with a capacity of 5200mAH.
    •  3A Polyswitch is used as a circuit breaker mounted on the battery connector.

Sound
    • Mylocosound steam sound card mounted in the ashpan
    • Speaker mounted in ashpan. IR sensor mounted externally to allow adjustments.

Radio Control

    • Hobbyking” HK-T6A V2 Receiver (Rx).
    • Hobbyking”HK-T4A V2 Transmitter (Tx). 

Components

Component Locations;

Coal Bunker
    • Motor controller mounted under the original circuit board mount.
    •  Receiver on top of the original circuit board mount.

Motor Controller Mounting

Receiver Mounting

Water Tank
    • A 14.4V 4S2P 18650 Li-ion battery pack (This replaced the 14.8V 4S Turnigy Graphene LiPo battery which failed), mounted in the Water Tender on the weights giving a nominal 14.4V and a capacity of 5200mAH. 

   • A polyfuse with a trip current of 3.7A is fitted to the positive lead of the battery for protection against overload/Short Circuit.
    • A HobbyKing battery monitor board is connected to the battery balance lead set to give an audible warning at low battery voltage to prevent over discharge.

The unregulated battery powers the Radio Control components, Front and Rear Light, and the Motors.

Battery Mounting and Polyfuse

Polyfuse Close Up

Ashpan
    • Mylocosound sound card.
    • Speaker is mounted in the ‘ashpan’ behind the steam motor (flicker circuit board removed).  Mounting the speaker behind the motor gives a more realistic sound.

Originally an oval speaker (pictured above) was used but was later replaced with round speaker to give improved sound when outside.

Sound card Mounting

Speaker Mounting

IR Mounting

Wiring

The Motor Controller, Receiver (Rx), in the Coal Bunker are electrically connected to the battery via a lead which terminates in a header that plugs into the existing eight (8)-pin socket mounted on the connector circuit board.

Two (2) positive (+ve) pins and two (2) negative (-ve) pins are connected in parallel at both ends (plug & socket) to share the current carrying load.

The remaining four (4) pins are the Rear Motor connections and the Rear LED (with current limiting resistor).

Connector Board Wiring

A DPDT switch under the Water Tender is used for power ON/OFF. (Battery is removed for charging to mitigate risk of fire/explosion.)