100% Pneumatic Timer/Chute Deployment

Discussion about deployment systems including altimeters, timers, air speed flaps, servo systems, and chemical reactions.
User avatar
marksmandcs
WRA2 Member
WRA2 Member
Posts: 13
Joined: Tue Sep 20, 2011 10:01 am

100% Pneumatic Timer/Chute Deployment

Post by marksmandcs »

It has been a while since I posted anything here or messed with water rockets. My kids got me back into it last year and I wanted to share some new water rocket "technology" I developed recently. Perhaps to inspire others? I'm not sure if I could sell these parts so I figured I'd share the idea. Its complicated mathematically but mechanically quite simple.

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.
Attachments
first four prototypes (critical details withheld ;) )
first four prototypes (critical details withheld ;) )
PneumaticChuteConcept.jpg (187.95 KiB) Viewed 8 times
ready to launch
ready to launch
Resized_20210328_165322 (1).jpeg (493.1 KiB) Viewed 8 times