Last spring I decided to get something new going in the shop. I had a set of flywheel castings under the workbench since 1993. I’ve always liked the design, 9-inch size and look of them.
After machining them, I decided I should put something between them. I called Paul at Debolt Machine and asked him to send me a helical gear set. So with a pair of machined flywheels and a gear set, I ended up with this vertical model. The entire body of the model is machined from solid 6061 aluminum stock. One thing I decided to do differently was use cast bronze for my cylinder sleeve. After using cast iron for many models over the years, I figured the bronze should be fine. Time will tell.
The crank shaft is one piece made from C1018 low carbon ground flat stock. Having a set of straight cut gears laying around, I decided to put them on the driven side of the engine and use them for ignition timing. The model uses a 10-mm spark plug to fire off propane. The flywheel rims are polished nickel plated. After looking at David Williams masterpiece scratch-built model in the December/January 2009 issue of GEM, I’m thinking two cylinders would be a new challenge.
Jim Limacher, 5340 Montecito Ave., Santa Rosa, CA 95404; (707) 545-1130;limacherj@comcast.net
