Today I finished installing RCS battery R/C and Sierra sound in both an Accucraft C21 and K27.
Here are a few pix on how it was done.
Not knowing what the actual current draw requirements were I chose to use 5 amp RCS Basic+ motor drivers.
As the owner did not want to have any holes drilled in the bodywork I opted to mount the charge jack and ON-OFF switch behind the tender front coal access plate on both locos. This simply lifts up with your fingers.
The pcb in front with the two big coils is the unit I supply for heavy duty trail car installs. It usually fits behind a box car door so it was perfect fot use here.
The C21 has well thought out wiring that does not require any modification in the loco. The K27 is a different story. More later.
The C21 normally has a distribution pcb behind the sliding front plate which was in the way and not required so I removed it. The BASIC-5+ Motor Driver and the BIK-TC5a were both mounted with silicone adhesive on an L bracket I made up in styrene.
This assembly was also glued in place with silicone. Another sheet of styrene was glued to the speaker and back of L assembly as the support for the Sierra sound and RCS sound trigger components.
On the C21 I used two 8 cell (9.6 volt) 2,500 mah AA NiMh packs wired in series to give 19.2 volts nominal. 22.5 volts when fully charged. These were also mounted with silicone on each side of the tender.
This close up might give a better view of the parts.
For both locos I made up reed switch chuff timers from readily available alarm system parts and used two very small rare earth magnets super glued to the non metallic wheels. This gives almost exactly 4 chuffs per driver wheel revolution. I removed most of the