Assemble by threading nylon string through the holes in the sides of the frame and torso. The fishing line I used is #4 (0.330mm or 16lb). The size of the test tube is H75mm x 10mm in diameter.

Threading the line requires some time and patience. The model of it has a triangular hole drilled 1 mm wide and 1 mm high, but due to printing errors that hole may not be threaded through (this depends on the performance of your printer). In this case, use a thin pin vise to drill the holes. Or, using a thin metal wire is also effective.