Another fabulous model from Dapol, the O gauge Jinty 3F is a piece of cake to fit DCC sound into.
Remove the 4 retaining screws and the body lifts off cleanly. Unplug the 2pin mini connector for the firebox glow while you are working. Remove the 21pin blanking plate. Reveals the empty boiler.
Here is some of the potential kit, including some figures from ModelU.
Add wires to the speaker (Zimo LS40X22X09-2W dual Dumbo) and for the stay-alive capacitors. There is plenty of room in the boiler for the speaker, and just about enough for a pair of 2200uF electrolytic capacitors end-to-end. A single capacitor would have been fine, but we like a bit of overkill! NB alternative speaker is IceCube40X18X09-2W.
Connect everything up and cover the various components in Kapton tape to given them protection.
Test, and secure the speaker and caps in the boiler with a little Black Tack, then refit the body... done!
Front lamp... drill through the frame to feed wires through. The YouChoos lamp has Black Tack inside, so squishes nicely onto the model's existing lamp iron. A little super-glue to keep it in place permanently. Drill a hole directly underneath the chimney to feed the wires into the boiler, and create a shallow channel for the wires to sit in under the frame. Once the glue is dried underneath, paint black.
Rear lamp... small hole in the bank of the bunker to feed wires, and squish the lamp onto the existing lamp iron using a little spot of super-glue to give it a some stability. Feed wires through the coal chute into the cab and drill a wide-ish hole near the back of the cab floor so the wires can be fed under the cab floor and out through another small new hole just under the firebox flicker board. Paint the exposed sections of wire black to disguise.
Add resistors to each blue (positive) wire from the lamps and cover in heat shrink.
Solder the lamp negative wires (white and yellow) to the various output feet of the 21pin board. We'll use standard F0Fwd and F0Rev for the front lamp to make it directional, and FA2 + FA3 for the rear lamp. FA1 is already in use for the firebox flicker light. The decoder will need to be configured to control FA2 and FA3 directionally.
Dirty chappy time... fabulous figures from ModelU need painting and weathering.
In they go, reassemble everything and track-test the Jinty.
Construct a platform in the bunker to hold the coal (I used some card, then fixed and covered in Black Tack), some UHU on top, and sprinkle with coal (from Green Scene).