My model engineering “career” got off to a great start at school. At 12, I made a single cylinder steam engine, and the following year a twin cylinder double acting engine. My interest in model aircraft encouraged me to design and build a single cylinder compression ignition(modellers call these “diesel” engines, but they are quite different to 4-stroke diesels) engine. This ran OK, but never flew in a model. Here it is in bits…
Here it is running –
I wanted to progress to a turbine, but my teacher felt something bigger for my A-Level metalwork project was better. He had seen papers on friction welding, So I drew up a machine to fit onto a workshop lathe, giving us a stiff base and integral power source. This was made and it successfully welded steel, aluminium and copper. We even managed dissimilar metal welds. Most welds were in rods about 6mm diameter.
Here’s a general picture of it , mounted on a Harrison lathe: