BUILDING Scale Models

| August/September 1986

  • The Rumely Oil Pull tractor

  • The Rumely Oil Pull tractor

1362 Valley Road Oshkosh, Wisconsin 54904

I would like to share with others my hobby of building scale models. I have always been interested in the Rumely Oil Pull tractor but rather than trying to obtain and restore one I decided to build a half scale model. At first I was going to use one of my antique gas engines for the motor but then changed my mind and built the whole thing from scratch.

The first step was to locate a full size tractor. I was fortunate enough to find one, a 1920 or 1921 Model 20-40 on a farm about ten miles from my home. My wife and I made many trips to this form, measuring and sketching every part we could get at. We also took numerous pictures. At one of the old time engine shows I found a Rumely book showing the breakdown of the engine, transmission, drive gears and running gears. This gave me much needed internal specifications and saved many trips back to the 'parent' tractor.

The first thing built was of course the framework and then the wheels. I had to get assistance for these. I had the metal for the wheel rims rolled at a sheet metal shop. I then made up the hubs and spokes and welded them all together.

To build the radiator it was necessary to deviate a little from the authentic construction. I finally settled on conduit for the cooling tubes and used 81 to build the radiator half scale. It works with the same efficiency as the original.

Looking for a flywheel I found that one of my old gas engines had one that was just the right size. Not wanting to rob that engine I sent the flywheel to my brother John in Minneapolis who has a machine shop. He had a duplicate cast for me and did the necessary machining for use on the Rumely.