scsager
08-27-2011, 06:28 PM
Both Goblins were built about a year ago. Nose cones from Semroc, everything else from parts I had laying around. Today would be the first flights for both.
First to fly was my 2X Green Goblin on a 29mm E16-4 White Lightning. I had a rare (for me) copperhead failure on the first attempt. The igniter burned away without lighting the motor. The White Lightning propellant may have oxidized some because this motor was built about a month ago, but I was unable to use it at the time. I tried replacing the copperhead with a Quickburst dipped Igniter that I had with me at the pad, but I couldn’t get it through the small nozzle. I took everything back to the car for motor disassembly.
The copperhead had burned a hole thru the masking tape at the top of the grain, so I replaced that as well. This seems a little risky, and I have to admit I was concerned about a cato with a “re-assembled” motor. I could have sanded the grain slot to clean away any oxidation… but I didn’t have anything in my tool box that would work. (I usually keep an emery board handy for just this type of thing)
The Quickburst igniter lit the motor easily, and The Green Goblin had a nice flight to about 500 ft. First flight – smaller motor. I think it will fly great on a G motor. :)
Next it was my daughter Stephanie’s turn. She called her rocket the “Goblin Cheese Shredder”, and entered it in the Jarosch Cup contest. After loading the ounce of Edam Cheese into our Top Secret Cheese holder, it took the combined efforts of Steph, her Mother and I, to pack the 4inch by 12 foot Mylar streamer into the Goblin’s BT-55 airframe. Including the E15-7 White Lightning, the rocket weighed 5 ounces. As you may have guessed, Steph was focusing on the “Duration” portion of the event.
Skies are clear, range is clear, timer is ready… lots of folks watching… It went up real fast. :cool:
OpenRocket sims it at about 2400 feet. (probably overstated) The Goblin is only 14 inches long. We were all hoping the 12 foot Mylar streamer would help make it visible. We were expecting at least a minute of flight duration. Lots of folks saw it go up... We all kept looking for a minute or two...
The wind was blowing towards the south… Somewhere in Illinois a squirrel or chipmunk is probably enjoying that delicious Edam cheese. :D
First to fly was my 2X Green Goblin on a 29mm E16-4 White Lightning. I had a rare (for me) copperhead failure on the first attempt. The igniter burned away without lighting the motor. The White Lightning propellant may have oxidized some because this motor was built about a month ago, but I was unable to use it at the time. I tried replacing the copperhead with a Quickburst dipped Igniter that I had with me at the pad, but I couldn’t get it through the small nozzle. I took everything back to the car for motor disassembly.
The copperhead had burned a hole thru the masking tape at the top of the grain, so I replaced that as well. This seems a little risky, and I have to admit I was concerned about a cato with a “re-assembled” motor. I could have sanded the grain slot to clean away any oxidation… but I didn’t have anything in my tool box that would work. (I usually keep an emery board handy for just this type of thing)
The Quickburst igniter lit the motor easily, and The Green Goblin had a nice flight to about 500 ft. First flight – smaller motor. I think it will fly great on a G motor. :)
Next it was my daughter Stephanie’s turn. She called her rocket the “Goblin Cheese Shredder”, and entered it in the Jarosch Cup contest. After loading the ounce of Edam Cheese into our Top Secret Cheese holder, it took the combined efforts of Steph, her Mother and I, to pack the 4inch by 12 foot Mylar streamer into the Goblin’s BT-55 airframe. Including the E15-7 White Lightning, the rocket weighed 5 ounces. As you may have guessed, Steph was focusing on the “Duration” portion of the event.
Skies are clear, range is clear, timer is ready… lots of folks watching… It went up real fast. :cool:
OpenRocket sims it at about 2400 feet. (probably overstated) The Goblin is only 14 inches long. We were all hoping the 12 foot Mylar streamer would help make it visible. We were expecting at least a minute of flight duration. Lots of folks saw it go up... We all kept looking for a minute or two...
The wind was blowing towards the south… Somewhere in Illinois a squirrel or chipmunk is probably enjoying that delicious Edam cheese. :D