One of the many exhibits which attracted a lot of attention at the 2011 Midlands Model Engineering Exhibition was this 1:3 scale Foden DG4 7.5 ton flat back lorry by Bob Fawcett. We have seen a great rise recently in kit built trucks, which are excellent, but it is always good to see scratch built models as well, especially petrol powered.

The original lorry was built in 1940, the year in which Bob was born. Bob’s model is based on a 1985 design by Ray Prime. He produced two versions, a timber tractor and a flat back lorry, which were described in Engineering in Miniature. Castings to the original design are available but Bob produced his own patterns to include some design changes he made. Changes were necessary to cater for some materials and components which were no longer available. He also reports that his castings, produced by a local foundry in Leicestershire, cost less than the standard ones.

The model is powered by a 5.5hp Honda GX160 petrol engine fitted with a reduction gearbox and centrifugal clutch. The rear axle is fitted with crossed helical gear drive and a twin bevel gear differential with three pinions. The gearbox provides two forward speeds and reverse. Hydraulic brakes operate on all four wheels.

It is fitted with working side lights and a horn. The Foden badges were cut with a hand fret saw and finished with needle files.  The sign writer who worked on the model was coincidentally the same man who worked on the original when it went into preservation.

Fuel is delivered by an electric pump connected to the main petrol tank and pumps petrol to the original Honda tank concealed in the packing case on the back of the lorry which then gravity feeds the engine. The lorry is driven through a removable panel at the back of the cab.

The model took four years to build and cost just under £4000.

Bob Fawcett’s