Project
1227 Flight

Results

• Overall this day was very successful in that two very important design flaws were found and can now be corrected for the next vehicle design.
• The first and most obvious item was the failure of the cardboard tubes used for the rocket body. The engines were placed in the forward section of the rocket and were designed to fire through the fin section. Even though the inside of the cardboard tube was treated with high temperature paint, the velocity and high temperature of the exhaust gasses caused the tube to unravel mid flight which in turn caused the structural failure of the engine set. However, all the engines fired perfectly and would have performed flawlessly if the vehicle had not disintegrated.
• Since the engines were in the forward section of the rocket and fired through the fin section, the slightest bit of wind caused the rocket to veer into the wind even with 1.5 caliber stability.
• Four static tests were also performed with Pourstone nozzles instead of epoxy / Kno3 nozzles. The PVC shoulders holding in the nozzles were too weak and all the nozzles blew out. However, pressure readings did climb up to a steady 120 pounds of thrust before the nozzles blew out. This is considerably better than the 75 PSI max with the epoxy / Kno3 nozzles.

Construction

• 8 3/8" cardboard concrete form tubes were used for the structure of the rocket body.
• Three 1/2" birch plywood bulkheads and 1/4-20 aluminum threaded rods made up the structure of the engine set.
• Seven engines with epoxy / Kno3 nozzles were in each rocket.
• Total impulse was 7000 Ns. with an average thrust of 420 lbs.
• Two relays were used for the recovery device. One DPDT relay was used on ignition to start another solid state relay with a time delay of 20 seconds.

Pros

• All igniters worked.
• All engines fired in both rockets at the same time.
• All engines held together.
• Rocket cost was under $200 including engines and electronics.

Cons

• Another body will need to be designed out of a material that can withstand the heat and high velocity of the exhaust gasses.
• The fin section will have to be redesigned to prevent wind cocking of the rocket.

Pictures

Video

• Flight 01
• Flight 02
• Static 03 gauge
• Static 04 gauge

CAD Drawings

• Rocket design .dwg
• Rocket design .pdf
• Engine deisgn .dwg
• Engine design .pdf

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