Seems nowadays everything HAS to be aluminum. But you won't find any aluminum gears, just boxes to contain them. If only an iron T-5 box were available.
Yeah, engines are aluminum, too. With carefully placed gussets and strengthening shelves where lots of distortion is expected. But, NO aluminum crankshaft. Or other highly-stressed parts. Because aluminum stretches and bends easier than iron or steel. A hunk of steel, ANY steel, hard or soft, has a Modulus of Elasticity of 30 million psi; Aluminum is about 13 million. That means an aluminum part compared to a steel one will deflect 2-1/2 times as much as the steel one. For wearing purposes, only 1 or 2 types of aluminum alloy are suitable for bearing surfaces, Aluminum Bronze being one. I used it when making my live steam locomotive, for the pistons and valves. Here I go, off-thread, again....
Yeah, engines are aluminum, too. With carefully placed gussets and strengthening shelves where lots of distortion is expected. But, NO aluminum crankshaft. Or other highly-stressed parts. Because aluminum stretches and bends easier than iron or steel. A hunk of steel, ANY steel, hard or soft, has a Modulus of Elasticity of 30 million psi; Aluminum is about 13 million. That means an aluminum part compared to a steel one will deflect 2-1/2 times as much as the steel one. For wearing purposes, only 1 or 2 types of aluminum alloy are suitable for bearing surfaces, Aluminum Bronze being one. I used it when making my live steam locomotive, for the pistons and valves. Here I go, off-thread, again....