#11
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I had a Prodyne Swallow that was gifted to me.Unfortunately it was destroyed in a fire I had nearly 2 years ago. (Along with lots more goodies). I believe I traced the fun pattern.I'll see if I can find it and lost it this weekend
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Jeffrey Deem NAR16741 CIA section 527 |
#12
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I believe the motors shown in the catalog were pressed black powder, not composite propellant.
Because John was using a phenolic case for those designs, he could run a higher chamber pressure and hence deliver a little more Isp. John had an investor for Pro-Dyne, and they spent a lot of money on a fancy rotary motor press, very similar to what Vern made (Mable). John failed to understand that, when you press a kraft paper case, it expands. They started to make the first run of 18mm engines compatible with the MMI-sized motors, and they couldn't get them out of that machine! That killed the whole project, John told me, because they didn't have enough money to fix the machine. (Vern designed Mabel with a clamping mechanism that held the motor case in place, but opened slightly and released the case after pressing. Vern's experience was in fireworks, where they were familiar with that phenomenon; John was as a Thiokol rocket engineer and he was not. Because John used hard, stiff paper phenolic cases for his bigger Pro-Jets, he never ran into the problem until he made the rotary machine designed for kraft paper cases.) I'm not so sure that the V-2 was the only kit Pro-Dyne ever produced. I went to John's estate sale, and bought about 200 hardwood nosecones (about 1" in diameter and 3" long) and the whole lot of convolute tubes to match. I ended up throwing away most of the tubes, as they warped badly. I still have a box of good, round, clean tubes, however. I haven't quite figured out what I am going to do with the stuff. The nose cones are of very good quality. I am considering getting a spiral wound tube made to fit the cone and use that in some "short run" NCR kits. So many projects, so little time. Matt |
#13
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I love the look of the Sparrow's fins. If anybody recreates them, please post the template here!
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NAR #27085 - Oregon Rocketry - SAM |
#14
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That would be great. It'll be interesting to see how close I come.
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Bill Eichelberger NAR 79563 http://wallyum.blogspot.com/ I miss being SAM 0058 Build floor: Estes - Low Boom SST Semroc - Marauder, Shrike, SST Shuttle In paint: Canaroc - Starfighter Scorpion Centuri - Mini Dactyl Estes - F-22 Air Superiority Fighter, Multi-Roc, Solar Sailer II, Xarconian Cruiser Semroc - Cyber III Ready to fly: Estes - Solar Sailer II Semroc - Earmark |
#15
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Thanks for this, Earl.
Quote:
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SAM #0031 |
#16
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lI'm sorry to say that the fin pattern is not where i thought it was. I believe I still have it but have misplaced it.My apologies.I will post it if and when I come across it. I have many boxes left to sort through.
On another note,the Swallow I had used the larger tube. Parallel wound
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Jeffrey Deem NAR16741 CIA section 527 |
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