Manufacturer: | Scratch |
Brief:
I'm always looking for rocket parts, and couldn't pass up this daiquiri glass from the Paris Hotel and Casino in Las Vegas. It'll fly on 24mm motors.
Construction:
Parts list:
Construction began last October when I drank the contents of the glass. The glass conveniently came with a removable top (nose cone). Although there is no real shoulder, it does snap in place and should stay on well.
Next came the actual rocket building.
A BT-60 fits nicely in the upper neck so all I had to do was cut a hole in the bottom. I started the hole with a circle cutter on a hand drill and finished it with a hobby knife. I slopped some 5-minute epoxy around the inside of the glass where the BT-60 was inserted. This pooled and retained the tube. I added a standard 24mm motor mount: 2 rings, a coupler tube and an engine hook. A length of Kevlar twine was attached for the recovery harness. I also adjusted the upper tab of the hook so I could use 24mm RMS motors.
I picked a spot on the outer edge of the lower section of the tower and ground holes to accommodate a piece of 10.5mm tubing, which works as a 1/4" lug. The location is far enough out so the rod will clear the nose cone. The gap between this tube and the opening was sealed with epoxy clay.
Epoxy clay was also used in the tip of the nose (straw hole) and retains a loop of 1/8" Kevlar. I tied a long piece of elastic to the Kevlar leader and then to the loop on the nose cone.
I created a RockSim model early on and spent a lot of time thinking about stability. I applied Bruce Levison's base drag method. This almost convinced me that it could be stable without fins, but subsequent discussions on TRF and comparisons to my Quest DC-Y Space Clipper made me reconsider.
While at a club building session, I cut some fins from clear Plexiglas using a miter saw. This worked well. Plexiglas is not the best choice but it was scrounged from an old screen protector for a big screen. Now that I think of it, I really don't know what the material exactly is. I cut some small through the wall tabs and attached the fins with 5-minute Epoxy.
Finishing:
For now, it will fly unpainted.
Flight and Recovery:
I decided to fly the Eiffel's Nightmare on an F24. The sim showed this would give it a nice ride. I adjusted the delay from 7 to 6 seconds to more closely match the simulation. Despite the stiff winds, the boost was fairly straight. The rest of the flight wasn't that good. The rocket stopped quickly due to the high drag design and lawn darted a split second before ejection. RIP.
Summary:
Next time I'm in Vegas I'll pick up a replacement. The concept was cool and it flies well (or could fly well). I still have the fins and the motor mount. I'll chalk this disaster up to operator error. At best, this is an example of GIGO (garbage in, garbage out).
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