Zane Middle School multiple rocket launcher: Difference between revisions

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Abstract

The purpose of this project is to create a system to launch multiple paper rockets at once using air pressure. Zane Middle School teacher, Mr. Pinkerton was previously using a commercial Ultra Stomp Rocket bladder to fire off paper rockets one at a time. Triple B built and designed a system that fires at least six rockets at varying degrees of inclination. Triple B built undertook this project because of Engeneering 215 Intro to Design, a course at Humboldt State University instructed by Lonny Grafman.

Background

Problem statement and criteria

Description of final project

The Main Chamber rocket launcher design, illustrated in the table below, is made out of two different sized PVC tubing, six solenoid valves, a Schrader valve, shelving brackets, hook and loop pads, and a bicycle pump. Nine sections of one and a half inch diameter PVC tubing cut to four inches long are combined with six tee reducer joints and two ninety degree elbows to form the bent pressure chamber that the design gets its name from. All of the PVC pieces are glued into place. Additionally there are six sections of half inch diameter PVC tubing cut to three inches placed in the top part of the tee reducer joints. The six solenoid valves are then attached to the half inch PVC with an adapter. Screwed onto the end of the each of the valves is a section of half inch diameter PVC tubing cut to one foot with an adapter glued onto the end. The two ends of the bent pressure chamber are sealed with one cap that adapts to a Schrader valve and another that adapts to a one-hundred P.S.I. pressure gauge. The pressure chamber is pressurized with the bicycle pump to the desired P.S.I. and then the button is pushed to open all of the valves releasing the pressure and launching the rockets. Finally, this entire system is angled and supported by a rod that is attached to the top of the pressure chamber. This rod adjusts the launch angle by being put into different slots in the shelving brackets.

Picture	Description
	PVC
	Polyvinyl Chloride is a hard plastic material mainly used in residential plumbing. The specific tubing we are using has been rated for 480 P.S.I. before failing. PVC parts are not only numerous and diverse, but they are also easily connected. PVC glue is comparable to concrete once it hardens and it is nearly impossible to separate two pieces of PVC that are glued together. Additionally, PVC is generally very inexpensive because it is a plastic and is mass produced. Since PVC is designed to transport fluids it can be made air-tight fairly easily.
	Solenoid Valve
	The pressure release valve implemented is electromechanically operated at the push of a button. The two-way valve is controlled by an electric current that runs through a coil opening the valve. Once the valve opens the air is released from the chamber and flows through the outlet. This valve was implemented because it has a fast release and a high reliability rate. Each valve requires about 320 mA to run at twelve volts, requiring about 3.84 watts to run at the recommended settings.
	Frame
	The frame is made out of shelving brackets, aluminum tubing, and door hinges. The shelving brackets were cut into about two and a quarter feet long sections. The door hinges were then welded onto the bracket. The aluminum tubing was cut down into sections of eight and three-quarters inches in length and were subsequently welded to another set of hinges. Hook and loop pads were stuck onto all of the hinges and their corresponding place on the main chamber. This allows the frame to be attached and detached at will. The frame can support the chamber at multiple different firing conditions. Special angles like 30°, 45°, and 60°
	Wiring
	The valves are all wired in parallel powered by one twelve volt battery. In a parallel circuit all of the voltage is constant so all of the valves will open at the same time and speed. All of the wiring is hooked up with alligator clips for easy set-up, take-down, and maintenance. The circuit will probably only have a net wire loss of less than 0.3 volts across the entire system.
	Power
	The twelve volt battery system is made of cells of ten AA NiMH rechargeable batteries. One cell is capable of providing 2000 mA. One cell can provide 24 watts. The valves require a total of about 23.04 watts. The power supply takes less than four hours to charge with the commercial charger.
	Trigger
	The button is a 100mm wide big red push button. The button triggers the system wirelessly via an RF transmitter. The button has a separate battery compartment and takes two AAA size batteries. When the button is pushed the valves are opened, but all other times the valves are closed. The button is in a PVC case for structural and aesthetic improvement.

Costs

Testing Results

The system successfully launched all six paper rockets at every launch angle. However, the stand was getting a bit shaky anytime we tried to fire at higher pressure than _____ P.S.I. For that reason we are suggesting that no one operate the system past _____ P.S.I. Also, all of the rockets went less than _____ feet below _____ P.S.I. therefore it is rather pointless to use the device at anything less than _____ P.S.I.

How to build

Use Template:How_to

Discussion and next steps

References

See Help:Footnotes for more. Template:Reflist