Assemble crankshaft with pistons as pictured. There are two pistons (colored yellow and blue), each consisting of two flat piston plates and two vertical piston heads. The pistons are mounted in a cross configuration around the stationary crankshaft. Use a M2x14 (or M2x16 as long as it is not sticking out) bolt to reinforce the stator. Insert twenty M2 nuts in the bottom rotor part. Use one M2x16 screw (with nut inside stationary crankshaft) to screw the backplate and bottom rotor parts together.
The cylinders are sized 18x18 mm, so cut silicone seals to approx. 18.3x18.3 mm using the seal cutter. Apply blue silicone to the surface of the middle housing part and grease (e.g. vaseline) to the silicone seals. Mount middle housing part as pictured.
Position top rotor part and screw in twenty M2x24 bolts (or raised countersunk M2x25 as pictured).
Fix frame with four M3x10 bolts and nuts. Adjust central screw to balance low friction with low leakage and lock that screw with another screw (M2x10) and nut. The pictured frame cover is for 4 mm clip sockets. Plain 4 mm and M5 socket versions are also available.
The motor is now ready!