Despite little machining experience, builder creates near-exact 1/8-scale model of an 80 HP Case steam engine
This model has an overall length of 32 inches and a width over rear wheels of 13 inches, and is 15 inches to top of stack and weighs approximately 85 pounds.
The boiler has the same number of flues, rivets and stay-bolts as the big job. Each rivet head was shaped by a specially made cutter to produce the cone shape, the arc of the cone having a radius of 100th of an inch. It was necessary to make special threading taps with a pilot to thread for the stay-bolts between the top of the boiler and the crown sheet. It is also fitted with rocking grates and lever. All wheels have the same number of spokes as the prototype and gears have the same number of teeth. Local machine shops could not cut these gears according to my requirements, so it was necessary to have it done in Akron and Detroit.
Every feature on the model is just like that on the big engine with a few exceptions. I purchased the steam gauge and oil pump, and a model friend gave me castings for the engine frame, crank disc and fly-wheel. The injector is an exact model but does not work as I never finished it up inside. However, the little ejector works like a clock, it’s amazing to see it draw water from a glass container and force it into the platform tank.
It was also necessary to make special left-hand taps and dies in order to obtain adjustments on the links between the upper and lower cannon bearings, valve gear and fly-wheel friction clutch.
The boiler is also provided with hand clean-out holes just like the big boiler.
To make the model of the governor, I purchased an old 2-inch New Judson governor, took it all apart and measured each piece to make the model.
I could not find a stock worm and worm gear in the size that I wanted for the steering gear so I wrote a gear company for the price on a special worm and rear. They quoted me a price of $30.
So I sent off for a book on gear cutting and studied that book one night to figure out the size of the blanks. The next night I made a hob in my little basement home shop and the next night I made my gears. They work perfectly, and I don’t believe anybody could make a pair that would look and work better.
I am definitely not a machinist nor claim to be one. I am a banker and have been for over thirty-five years and never even worked in a machine shop. I just bought a lathe with some attachments, a drill press and some hand tools, and went to work.
Any of you who would like to build a model engine bad enough and are willing to work hard and have plenty of patience, you might surprise yourself with what you can actually turn out.
It takes many hours to build a working model and one that performs well, but it is a genuine pleasure to see them come to life when you steam them up. IMA
Herbert H. Baker is from Pekin, Ind.