Sunday, July 26, 2009

Crazy Idea of the Day #1

Not going to be a regular feature, just I happen to have two of them today that are both big enough to have separate posts.

Okay, so the first crazy idea. This came about while building my Nike-Apache a few days ago. I noticed that the Apache on its own could be a good rocket with a few simple modifications. It's a solid 24mm minimum diamater model that only requires retention and a recovery system to turn it into a workable rocket that still qualifies it as a scale model.

However, the main idea is even cooler. Basically, the Nike-Apache kit is a very high-quality kit of a Nike booster that can be changed very easily and combined with other materials to make different models of Nike-boosted sounding rockets, all it the same scale.
  • For example, with new fins on the both stages and a small balsa or paper thickening/transition just aft of the nose cone, one can have a Nike-Deacon.

  • With just a slight thickening of the forward section near the nose cone, you can have a scale Nike-Cajun, which was actually the predecessor of the Nike-Apache.

  • With new fins in the forward section and leaving out the thickened forward fin can, one can make a pretty good Nike-Asp.
  • The Apache, Cajun, and Asp are all about the same diamater; the Tomahawk is somewhat thicker and would probably require you to re-turn part of the transition section to fit the larger tube; This wouldn't be too difficult with a lathe or largish drill and vise or drill press. To be in scale with the Nike, the Tomahawk would have to be about 1.45" (37mm); this could be thick-walled 29mm or 32mm motor tubing. Unfortunately, there's a gap between BT-56 (34mm) and BT-60 (42mm) with nothing really in between.

  • More difficult would be the Aerobee 350. First, there's the interstage structure, which requires a completely different transition, strong struts, and an electronic ejection system, more than likely, as the forward section is larger and probably heavier than the Nike body. Second, the Aerobee body is big - it requires a body tube about 3.5" in diameter, which is an odd and hard-to-find size, and might have to be custom made especially with the nose cone; it'd also have to be about 57 inches (4 foot 9) which makes for a giant rocket. Third, since it's a big rocket - about 10 feet tall and 3.5" wide - it's pushing several boundries, including the 3.3 pound limit, the limit of what three skinny interstage struts can hold, and also the lifting capacity of a 29mm mount that's designed for F-G motors. However, with a longer motor tube, I think a careful builder could easily fly an I200 so long as they reinforced the centering rings with plenty of epoxy and fillets. I plan to fly an H128 and possibly later an H165 Redline in my Nike-Apache, with wood-glue-covered centering rings and epoxy fillets on all four CR-motor tube joints and one CR-tube joint.

  • Finally, there's the Nike Smoke. This is the most difficult because it requires a huge custom nose cone. If you want it, then just get the kit from the same manufacturer, Cosmodrome Rocketry.

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