Page 26 - NMRA Roundhouse July-August 2018

Plymouth Narrow Gauge Diesel
Alain Kap MMR Part 2
The second part
of this build article I explain how I constructed the super- structure parts and hope you enjoy the model and perhaps inspire you to build your own little critter.
Hood
The hood is designed to fit over the vertical motor and the die-cast weight. I absolutely wanted to keep the weight for better power pick-up.
It is built up from different pieces of plain styrene to give it the rounded shape. It is complicated to describe the build in detail because it is
more a trial and error with lots of measuring and test fitting. The motor, mounted vertically, and the weight fill most of the hood, so careful planning is recommended. The different braces need to be placed in between. The hood skin is .005” styrene
sheet, wrapped around the braces and frame. Too much glue melts the styrene, so extra care is advised.
Plymouth diesels have a distinct radiator grille. I pieced it together using .010 x .060 strip styrene and added the “Plymouth” signage with Slaters 2mm letters.
On previous engines, I simulated
the louvered engine doors with quarter round styrene strips, but I thought that in a large scale, it must be possible to make them look like the real thing. On the prototype the louvers are basically stamped out of the sheet metal. To use a similar way I would have needed brass sheet to make the doors. Unfortunately Ididn’t have very thin brass sheet. Styrene would work also, but proved to tear out when I tried to open up the louvers. The solution is 160 gram copier paper. That’s approximately the double thickness of simple copy paper or sometimes called Bristol Paper. I first traced the size of the engine doors and the location of the louvers on the doors. Then I used
a fresh #11 blade in my hobby knife and cut the length of the louvers on the doors. With a small screwdriver, I lifted one side of the cut and carefully pried it open, until it the shape was right. I did the same with the remaining cuts. When prying the cuts, I secured the ends with
my finger nail, to avoid the cut from tearing up. After all the louvers were
opened, I secured the edges of the doors and the louvers with ACC. After drying, the doors were stiff like styrene.
Then I glued the doors to the sides of the hood. The door handles are formed brass wire. The hinges are small pieces of styrene rod.
I used a piece of styrene tube for the chimney and the air filter is an HO ventilator casting from the scrap box.
I made the lamp housing from a short piece of styrene tube, shaped with
a file. The legs from the warm white LED are used to attach the lamp to the hood.
To secure the hood in place, there was no way of screwing it down so I constructed some kind of guiderail for the hood to be attached to the front cab wall. This guide holds the hood in place and the friction of the walls against the weight and motor do their part also. I recommend to check the pictures to understand how it works.
Cab
The cab walls consist of four pieces, shaped from .040” plain styrene sheet glued to .010 sheet with rivets
photos by Alain Kap MMR
26 ROUNDHOUSE - August 2018