All enginebells are made out of  curved .5mm plastic strips. (3d made flat printed and cut as usual)

I then cover them in epoxy-putty and sand them down to make them smooth and nice.

The 5mm long RCS thruster bell was a very tricky little thing to get done. To make the small rings around it I had to glue these thin copper wires around it. It took forever to get it resonably good. And now i need 15 more of that little bugger…