I´ve found another foundry to entrust with the next, much beefier part(s). Hope they´ll do better.
In the meantime I´ve started making cylinders. They come in two rather small sizes, namely 10 and 13 mm inside dia., respectively.
This is my CAD drawing of the the circle turn cylinder. The piston rod is a mere 4 mm in diameter, even in 1/8. The cylinder piston is the 10 mm one. The stroke is 39 mm.
This is, obviously
, the real one:
The tubes here are just pre-cut.
The cylinder heads are at a 14.4 and 17.4 mm outside diameter, respectively.
Stefan