Farm Compost Diorama

This HO scale diorama was built for the Brandon Research Centre, a division of Agriculture Canada. Measuring 20 inches deep and 29 inches wide, it's an educational model designed to show what a typical composting system looks like and how it works, as well as demonstrate the benefits of the operation and the quick turnaround time of decomposition by turning, churning and aerating the material regularly.  The miniature tractor with the "Wildcat" turning machine, attached in the place of the tractor's excavating bucket, runs around the centre pile of the model simulating the turning process via a motorized chain drive system concealed beneath the diorama table. The drive unit is activated by pressing the button on the front of the model. The model is protected with a 1/4" thick plexiglass case, transparent on all sides and the top for maximum viewing.

The background behind the miniature trees is a printed photo of the Brandon Research Centre and surrounding grounds. This "cyclorama" was actually photographed from my own balcony, which just happens to provide best view possible!

These views show the model with the plexiglass cover removed for photographic purposes. The compost heap at rear simulates the various bits of grass and hay which is abundant in the unprocessed compost pile. The centre pile, which is being turned, is darker and more advanced in it's decomposition. The foreground pile, shown as a cutaway, represents a fully decomposed and finished pile, ready for use as fertilizer. The working surface of the model is correctly sloped to show how excess water can run off into trenches surrounding the paddock,  allowing this runoff to enter a nearby pond (on the right of the model, simulated with transparent resin) via a drainage pipe with a one-way valve.



The industrial John Deere tractor, modified slightly from a commercially available three inch long toy with the scratchbuilt "Wildcat" turning machine getting ready for another run. The wheel on the end of the outrigger can swivel just like the real thing as the tractor swings around each turn.



The powerful turning tines which operate much like a garden roto tiller are simulated here with a folding mechanism which allows the model to simulate the turning process when running over the compost piles, since it would be impossible to actually have the model work like the real thing. This is as close as it can get in a miniature simulation.


A closeup of the separate diesel engine and the "works" which run the turning machine, simulated here with bits of styrene plastic and cannibalized model kit parts. Not including the outrigger arm, the completely scratch built model of this "Wildcat" machine is a mere 2.5 inches wide! 

The two photos below show how the Wildcat "cheat" folding mechanism works. The tines assembly and the rear dust skirt are lightly hinged at the top and allow the simulated compost to pass underneath as the tractor is pulled along the slotted path.

The four shots shown below were taken in direct sunlight for more realism. The other shots above were taken in a studio setting with even but unnatural lighting, but does a better job of showing detail.





Among the trees and shrubs, a 3/4 inch long "Space: 1999" Eagle Transporter explores the forest behind the farm.... Just a little "in" joke!


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