MINNIE, a Model Steam Traction Engine

For some time I wanted to build a model of a steam traction engine. I was very inspired by the work of Fred Fox when I met him at the Kinzer fair one year. He had a couple great engines on display and I talked to him at some length about them. One interesting feature of Fred's engines is an all spur gear differential. I had never seen one before and was very interested in it. It is obviously eaiser to buid spur gears than bevel gears. I decided to build MINNIE, but to modify the design to include Freds differential.

The plans for MINNIE were published in MODEL ENGINEER magazine IN THE LATE 1970'S, then re-printed into a book. I bought the book on a trip to the London ME show. I understand the book in no longer available altough used copies might be found. I was written by L.C. Mason

When I started collecting materials for MINNIE the only pipe I could find for the boiler was 3" dia, and the plans called for 2.5". I decided to scale the engine up 120%. I keept the engine parts to the original size, but have scalled up the boiler and wheels.

I completed the boiler in December, 1996 and started the gear cutting during my Christmas vacation days. Here is a photo of the engine as of November, 1997.

After a year or so of work I put the project aside and left it. I did take it to a couple shows in its unfinished state. Finally, in the winter of 2003/2004 I decided the time had come to finish this project. Following are some photos of the finish work

First is a photo of the cylinder block. This was entirely carved from a 2" cube of durabar cast iron. A lot of milling and drilling and hand filing here!

This is a photo of the tender as I removed it to start painting. Note the brass sides were hammer formed over a hardwood block. The mechanism shown is to operate the brake band.

Next is the boiler, all stripped down to paint.

Here is a good view of the main motion work. The horn plates have been painted and the re-assembly is underway. Note that I cut all the gears from cast iron bar stock.

The cylinder block has been painted and mounted on the boiler. I decided to paint the boiler red after I bought a red new pickup truck. I bought touchup paint to match my 2003 Chevy- Victory Red!

Next the engine is all assembled. Note the air hose connected to the blow down valve. The engine has been run on compressed air. Note also the wood lagging fitted to the boiler. I used super glue to hold it in place while I was working it. Once it was all in place I wrapped it with a fiber tape, then installed the brass cladding.

Following are several views of the finsihed engine. Note the name plates spell MINNEY. There are two reasons for this. First, since I made a lot of changes to the original design mine is not really a MINNIE as L.C. Mason drew it.

The real reason is that my friend Larry Twaits made the name plates for me when he bought his new Gorton pantagraph milling machine. He asked his English girl friend how to spell Minnie and she suggested the 'ey' spelling.

The engine is still not complete. It needs a feed water pump, and fire grates and ash pan. I am not sure I really want to build a fire in it, after all this work. I am thinking about making a propane burner for it, which should be more convient for the shows.

Back to my home page