Project
1025 Flight.

Results

• I don't know what happened with this rocket and right now I'm too angry to find out. The same engine design worked perfectly on 920 and 413. I can't understand why clustering seven of them together would cause the rocket to fail when they worked so well alone. I put all my rocket stuff in the garbage after this flight and then a few days later pulled it back out. It's funny, but when you build a half dozen rockets and only four or five work, you still go away with a feeling of accomplishment. But when you put all that energy into one rocket that doesn't work, it's hard to see past the failure.

Construction

• This rocket had seven IE24 engines clustered in a 8-3/8" concrete form tube. The engines were held in place by a plywood bulkhead and marine 2 part foam around their entire length. The only difference between these engines and the ones that worked so well before was that I used 8 1/4-20 socket screws instead of 4 1/4-20 bolts to hold in the end cap and nozzle.
• In the past the IE24 engines have produced a maximum thrust of 141 lbs. With seven of them togeather, the combined maximum thrust for this rocket would have been close to 1000 lbs.
• The total rocket take-off weight was 40 lbs.
• The total fuel weight was 24.5 lbs.
• The rocket was stable with 1.5 caliber stability.
• A 4' plastic parachute was also included in the rocket.
• Engine cluster was forward of the fin section to add stability to the rocket. Holes in the fin section allowed the exhaust to vent without causing a vacuum.

Pros

• All engines lit at the same time. You can hear the pop of the core caps in the video.
• The rocket seemed to go up straight for what little time it did fly.
• Easy to construct.
• Low cost, the entire rocket without electronics cost less than $100.

Cons

• Something is seriously wrong with the engines. All of the engines shattered. In the past, I've had end caps blow out and nozzles blow out, but rupturing the PVC casing without a blockage in the throat, in my experience, is very rare.

Pictures

• PVC casings shrink about 1/4" after hot fuel is added.
• Engine casings.
• Finished igniters.
• Igniter in fuel, engine waiting for end cap.
• End caps attached.
• Concrete form tubes used for rocket body.
• Epoxy used to seal fuel in rocket from moisture.
• Plug in nozzle used to seal fuel from moisture.
• Hex set screws used to retain nozzle.
• New nosecone wood master used to make a mold.
• Making the nosecone mold.
• An engine cooling in the refrigerator.
• Nosecone mold finished.
• Finished engines.
• Forward bulkhead.
• Test smoke element.
• Engine cluster.
• Another view of the engine cluster.
• Nosecone in mold.
• Testing the smoke element.
• Nosecone attached to the cardboard tube.
• Primed nosecone.
• Finished smoke elements.
• Smoke elements attached to engine cluster.
• Nosecome attached to rocket body.
• Ignition lugs.
• Engines in rocket body.
• Rough fin section.
• Finished fin section.
• Engine electronics.
• Parachute made out of a 1 mil. plastic drop cloth.
• Grommets on parachute.
• Me next to the rocket.
• Fin section after landing.
• Another view of the fin section.
• Engine electronics after crash.
• Static test of an exact duplicate engine as the ones in the rocket, this one worked fine.
• Launch sequence.

Video

• 1025 flight.

CAD Drawings

• 1025 rocket design.

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