For sound enthusiasts of the railways of Victoria, Australia...

DCC for the Auscision N Class - nothing's difficult when you know how!

While most locomotive models are easy to disassemble and fit digital decoders to, there are the occasional releases which simply don’t want to come apart. Auscision’s recent N class diesel is one example. With a want to fit sound to such a finely detailed model, a method was developed to disassemble the body without incurring damage to all the fine detail parts.


At first, the body assembly feels very stiff, and to get things apart, we have to introduce some flexibility into the plastic assembly. To install a decoder, the aim is to remove just the centre hood  section, as the complete body assembly does not need to be completely removed from the chassis.


Warning: take care of fine details parts during handling, particularly the air intake grills under the radiator fans, lift-rings and walkways.


So here’s how the body ‘wants’ to be disassembled:


1)    Remove the tapping screws from the underside of the chassis, one is located at each corner of the loco.

2)    Remove the coupler screws, coupler boxes and couplers. Keep all the bits and pieces in a safe place.

3)    Undo the two screws, one either side of the fuel tank and back each one off by about 4mm, or until they are free from the part they screw into. There’s no need to remove them completely from the chassis. These screws hold the centre hood section down onto the chassis and walkways.

4)    Next, take a straight-slotted screwdriver, or an X-acto chisel blade. The latter is more effective as it nice and wide, but thin. Place the blade under the walkway, guiding it between the underside of the walkway and the top of the chassis, as shown in the following image.

     The purpose of the next step is not to remove the complete body assembly from the chassis, but to invoke enough ‘give’ in the body assembly such that the centre hood section can be lifted away from the cabs and walkways without damage.


5)    Gently, lever the body up by a millimetre or so. Work your way along the walkway from right to left and back again, inserting the blade where you can. The underside of the walkway has been superglued to the top of the chassis, and these bonds need to be broken. There are three dabs of glue under each walkway, one above the air reservoir, and one at each end of the walkway near the cabs. One can hear a crack when the bond breaks. The walkway is quite flexible under the force of the blade and will not be damaged if one is careful and methodical. It takes about three or four passes to get the walkway up off the chassis, per side. Do the other side of the model at the same time. The body assembly should sit about 3-4mm above its original position for the next step.

6)    Next, grip the center hood just behind the cab with thumb and index finger and push the cab down with your pointer finger. The cab moves the walkway down, exposing the lower edge of the center hood, see next image.

 7)    Next we want to expose the complete lower edge of the hood. This is best aided with a small screwdriver and some plastic or paper card. The card removes the risk of marring the painted surface. Hold the centre hood with one had as you push the walkway downwards, using the screwdriver in your other hand. The lower edge of the centre hood is now completely exposed, and the hood can simply be lifted vertically up and off the chassis, leaving the cabs and walkways in place. 

8)    Remove the DC jumper board from the 8-pin socket. Plug your favourite 8-pin NMRA compliant decoder into the DCC socket. Check your decoder manufacturer’s wiring code, but normally, the orange wire goes to Pin No.1 


9)     If the decoder operates okay, reassemble the model by pushing the centre hood back down over the chassis. Ensure the centre hood doesn’t catch any wires and that it is a neat fit with the walkways and cabs. Fit screws and couplers in reverse order to initial disassembly. Done.