Hey thats pretty interesting and I'll look into that. I had mechanical
parts in mind, upto even a simple combustion engine, and the gear and
clutch system of a small helicopter. I'm not gonna finish all my
projects but thats the scale of things I'm interested in covering.

So although aluminum is too soft for some of the jobs, it does make
for good structures especially in model airplanes.

On a side note, I'm wondering how much would the cheapest low-volume
high-precision lathing and milling machines cost. Given the largest
part is 10cm x 10cm but steel might be used...