Manufacturer: | Scratch |
Brief:
This is a Halloween-themed oddroc based on a toy coffin. It features a 24mm mount and patented 'Coffin Lid Ejection'.
Construction:
The parts list:
I slowly and carefully drilled a hole in the base of the coffin to fit the 24mm tube. A spent casing with the nozzle removed provides additional strength where the vent hole is located. The 24mm tube terminates on a plywood bulkhead plate that plugs the hole inside when the top is closed. The charge should push the lid open and hopefully the laundry will come out. An elastic shock cord attaches to a screw eye in the bulkhead plate. I also attached pieces of elastic and Kevlar® twine to keep the top from fully opening and breaking the hinges.
I made a RockSim file to check stability. I used circular components with frontal areas equivalent to the polyhedron shaped sections on the coffin.
Finishing:
Finishing consisted of painting the tube black and adding 'Boot Hill'-style inscriptions on the flip side of the 'RIP' fins:
Golden Scout #0869
"Lost in the NARAM-50 sky"
July 26, 2008Birdhouse Version 2.0
Mini-Mojo Fat Boy
"Turned into toothpicks"
9/18/2005
Died 9/21/2002
Rose from the grave 10/16/2004
Flight and Recovery:
I attached an 18" RocketChutes parachute to the shock cord and packed it in the upper chamber. Because there may be a leak around the bulk plate, I filled the remaining space inside the coffin with dog barf. The C11-3 was friction fit with masking tape.
I added a piece of masking tape to the leading edge of the coffin to keep it closed and opened the latch. The boost was nice and straight and ejection was near apogee. The chute even came out! Because it was so tightly folded for a few days, it didn't fully open, but it was enough for a soft landing.
Summary:
The coffin made for an interesting oddroc with a fairly unique ejection scheme. It at least worked once!>
As soon as I saw Dick Stafford's 'Boot Hill' rocket, I had to build one. It is a fun rocket, and I want to give all due acknowledgments to Dick! That said, I made one modification to Boot Hill that employs rubber bands to pull open the coffin lid, instead of using ejection gases to push it open. The ejection charge gases are now used to burn through a thread that is holding the coffin lid ...
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