How I made my Donkey Engine. 

I was given an old 303 cartridge shell casing to make a Donkey Engine boiler from, It turned out fine for 
making the boiler, after a little fabrication with various brass parts from my scrap box, here is how it 
turned out.

The next part of the operation was to make the skid for it to travel about on and also the water tank fitted at the rear. The water tank started life as a brass tube 5/8" diameter. 

The next project was to make a convincing gearbox. As I had an old set of small gears from a clock, I set about making the shell casing for it, out of brass sheet. Next, Inserting the gears so they would actually mesh properly, and adding the outside discs for the pistons.


How to fabricate some sort of realistic looking pistons was next on the agenda . The only thing I could think of was two pieces of brass tubing one to fit inside the other. The end pieces which fitted into the boiler were in actual fact two plastic bits from on old shay kit. The outside brass tubing was cut away with a round file, making the slots.

I then fitted the pistons to the boiler.

Then the whole assembly was fitted together.

The whole assembly was then fitted to the skid.

Next stage was to make the wood frame to house the roof, this was made using 1/16" square hardwood, the four corner pieces were reinforced with 1/32" by 1/16" hardwood on the outside, 


This was test fitted, and as I required the Donkey engine to have a jib on the front, to be able to unload logs, I made the jib using 1/16" by 1/8" hardwood, and braced it every 1/2".

Once this was made, the roof was added using corrugated plastic sheet. A hole was cut for the boiler to fit into and a flap was also added.

Now it could all be fitted together, and the whistle added on the boiler. The model was suitably painted, but as yet it is not weathered. 

Here she is in place at the log pond, just about to unload a giant redwood.