All work and experiments are coming together to complete 3 new water rockets. 1. An upgrade of the 'Black Beauty' to a 2.1L rocket (with a classic Robinson coupling: 1.5+0.5L) but without parachute. In the previous versions the parachute never came out so I hope the nose comes off at apogee and the rocket tumbles down 2. a Ø88 mm rocket with cargo and parachute. A modular system so the volume can be increased. 3. a Ø97 mm rocket with cargo and parachute. A modular system so the volume can be increased. The 1.5L bottles are Ø88mm, the 2.0L bottles are Ø97mm.
After several failures off spliced bottles, I started to make Robinson couplings but with the bottoms together. This makes a pressure vessel of 3.25L (with 2 x 1.5L bottles) or 4.25L (with 2 x 2.0L bottles). I connect these pressure vessels with 2 bottles caps glued together and drill a hole of Ø5 to 10mm.
For 1 connection I used "Bison Combi" and no screws. (A) For 1 connection I used "Bison Combi" and 2 screws. (B) For another one I first drilled a large hole trough both caps and then filled it with PU FIX. When it was cured I drilled a new hole, smaller than the first so the air can pass trough it. (C)
I did test the combination of 2 vessels and 1 connector. (A) did stand till 7.5bar but then after 1' at 7.5 bar it suddenly started leaking and the upper part flew away. (B) and (C) did stand the test at 120 psi for some minutes All pressure vessels did stand 120 psi. (2 x 3.25 L and 2 x 4.25L)
I also prepared a cargo bay and parachute deployment system for Ø88 and 97. The cargo bay can carry 2 MD80 camera's. An other cargo bay will also have a side opening system with Tommy timer to release an other payload on apogee. This can be a small tin soldier on a parachute or other slow falling objects. The parachute deployment system is a side deployment system with Tommy timer.
For the longer rockets I upgraded the launch pad with a guide rail.
After these successful tests I can start assembling all parts and prepare the launch.