Inverse Engineering

Project
304 Flight

Post-flight Analysis

This series of two flights and six static tests was to test and baseline the new flexible non-melted sugar fuel. All of the engines were case bonded and had internal pressures ranging from 250 to 450 psi without any cracking or pressure spikes. This fuel is perfect! It combines ease of construction, case bonding, and clay-like flexibility with reliable repeatability.
The first rocket went straight up and deployed it's parachute via a hot gas piston and came slowly down 200 feet from the launch site. The second rocket had a leak in the hot gas piston and failed to push off the nosecone resulting in a ballistic flight.
Static tests were done ranging in grain size from 23" to 40" with nozzle throats ranging in size from 0.78" to 1.031". All of the engines fired today had a KN of 300.
Alberto launched a successful flight with his SX epoxy based fuel in a 1.5" PVC engine and did several static tests as well.
My rockets weighed 14 lbs. total each. We didn't weigh Alberto's rocket but it was definitely under 3 lbs.
Ignition for both my rockets was wireless and on-board each rocket.

Construction

Fuel formula is 65% Kno3, 20% Corn Syrup and 15% Powdered Sugar. The mixture is heated to 210 degrees just enough to lower the viscosity of the fuel without driving out any moisture. It is then poured in the engine casing and an aluminum core mandrel inserted. In about an hour when the fuel was cool, the mandrel is removed and the igniter epoxied in the top of the engine core.
Rocket bodies were 3" ABS and fins were 1/4" plywood.

Pros