The Burrell crankshaft and layshaft gears join the crankshaft to the differential and the differential to the wheels. The crankshaft gear was made from phosphor bronze and as you see in the video this slides so that you can select between drive and neutral.
At first these gears look complicated, but they are actually quite simple. The most significant thing is the differential sits on the layshaft. This means it runs slightly faster than the axle speed and slower than the crankshaft.
The gears are all cut with a 0.5 module gear cutter and individually indexed.
The calculation is free to download as part of our workshop calculator.
Hopefully this next image helps to explain the Burrell Crankshaft and Layshaft Gears. The wheels are independent and rotate freely on a shaft that runs through the centre, this allows each to be independently driven from the differential.
I still need to add a tube over the top of the layshaft. I will keep this quite small so as to maximise access to the firebox door.
Read more about this 1/20th scale Burrell traction engine on the main page where we link to every major part and explain the design and making of.