- WRA2 Member
- Posts: 13
- Joined: Tue Sep 20, 2011 10:01 am
This system uses the air pressure from the rocket motor tank to charge a chute timer tank as well as the chute deployment charge tank. All that needs to be done to prepare for flight is to pack the chute and nosecone, fill with water, pressurize, and launch. The timer and chute charge are set and activated automatically by the motor charge pressure.
The timer starts when there is drop in motor pressure. The timer time is set by an adjustable valve or by changing an orifice. I've notice that the timer can somewhat adjust automatically to compensate for apogee caused by differences in launch pressure. I have not determined the ideal volume ratios to take advantage of this yet but I tend to stick to one pressure. It does NOT compensate for changes in water volume however. After the timer tank and charge tank reaches a certain pressure differential, the chute deployment valve pops open and the chute and nosecone are blown forcefully out of the rocket.
The main downside to the system is you must check for leaks occasionally, lube o-rings, and blow out excessive water that make its way into the timer tank. Other than that, it works pretty well so far.
- first four prototypes (critical details withheld ;) )
- PneumaticChuteConcept.jpg (187.95 KiB) Viewed 17 times
- ready to launch
- Resized_20210328_165322 (1).jpeg (493.1 KiB) Viewed 17 times
- WRA2 Member
- Posts: 235
- Joined: Sun May 07, 2017 2:18 pm
The idea reminds me of the Flushometer concept patented in 1906 by Sloan Valve Company. This is the timed flush valve one sees today on toilets in public washrooms. It also uses a timer employing a pressure differential and a calibrated orifice; the flush valve is kept open until closed by water coming through the orifice to fill a cavity that closes the valve.