Avery Traction Engine
Built by Brian Elvidge in October 2007
This American traction engine was made from about 1899 to around 1914. By 1920 the makers had gone out of business. There were two versions of this undertype tractor — 22HP and 44HP — used on American farms. Some have been preserved in the US.
This model is based on the 22HP version, and is loosely based on the GMM SML 25 by the late Dr. Cameron, with help from John Westwood of West London, at the Henly Gathering, who gave useful suggestions and detailed the pitfalls of this model.
The steering mechanism does not work well. It uses a screwed rod to move the front wheels, which is also how it worked in the prototype.
The second failing is the design of the undertype crankshaft, which is a major weakness, being very difficult to keep tight. However, the rear differential works very well.
The model is powered by a Meccano PDU or the equivalent Richard unit.
It lacks detail in the cab area as well.