Recycled Detritus - Design Hints
by Dave Watkins
1. Design hints for live internal combustion locomotives.
2. A simple plate clutch works fine. The usual centrifugal clutch used in model cars would work and may be better for radio control. Quite high revs may be needed to get a centrifugal clutch to bite. The plate clutch does have the advantage that the locomotive can be driven with the engine just ticking over.
3. I used a gear ratio of about 18:1. I would try for a bigger reduction, say 25:1 or so if I were building another. Robust chunky gears are essential. There is a lot of power to transmit. Fix the gears firmly to the shafts they drive. I found it necessary to pin the gears to the shafts. I drilled a cross hole straight through the gear and shaft and fitted a steel pin.
4. All bolts and nuts should be retained with lock nuts or locking compound. Make sure wheels and fly-cranks are secure.
5. A simple tinplate silencer box is effective. There is no need to buy ear defenders. “ Detritus” is quieter than my lawn mower.
6. The exhaust from these small engines is very oily. Try to fit an oil separator and arrange some way of draining oil from the silencer box.
7. Glo-plug engines are much much easier to start than diesels.
8. Do not place the fuel tank above the engine or you may flood the carburettor.
9. An engine of 2 cc generates far more than enough power for our needs. A smaller engine should work if you can find a suitable one.
10. Make sure the engine has an adequate supply of cooling air. Model car engines have a stack of fins to radiate the heat. An aero engine may get too hot in the enclosed space under a diesel bonnet.
11. Protect paint with a coat of hot fuel proofer.
If you want to contact me about leisure activities Send e-mail to: dave.watkins@blueyonder.co.uk