Modelers Corner

Little Sam Update

| March 2006

The Little Samson continues to develop its unique character. As you can see from the photos, all the secondary castings are here except for the main valve box.

Castings are designed with "chucking pieces" attached. These chucking pieces are very important, providing an easy way to hold the casting while machining. When developing initial patterns, machine processes must be thought out in advance and necessary chucking pieces designed integrally with the pattern.

It is easy to make mistakes in pattern making. I had no idea the ignition cam pattern was backwards until I machined it and set it in place on the engine! I simply fabricated one up and silver soldered it together. It is actually better than a casting.

For those familiar with the early N Samsons, the flyball governor draws the eye and instantly becomes the focal point. It is beauty and function combined in a delicate yet sturdy design.

The Little Samson governor is cast iron and steel, replicating the original materials used in full-size practice. The main driveshaft runs in a babbitted bearing. A pinch bolt secures the governor assembly to the top gland, which carries the speed control assembly.

After fitting all the little bits and pieces together, I am very pleased with the end result. It spins quietly with the fingers while the balls do that graceful "dance of the radius." The little bobbin valve moves up and down throttling an imaginary mixture of explosive gas. It will soon be put to work!