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Anyway, I usually pre-emptively scrape the nozzles of my sustainer motors using an appropriately sized drill bit. I suspect this results in a small amount of BP dust being left behind in the nozzle which enhances the ignition process. At least, that's my theory. The dust is in the nozzle, and not in the booster, but it's otherwise similar to what is described. Dust particles have the benefit of increased surface exposure (ala grain elevator explosions) and thus only a tiny bit of flame is necessary to light them up. Doug .
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Doug .
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I've never found it necessary to use a staging igniter. To give you an idea of how tiny the sustainter nozzles are we are igniting, look at the photo below. An Estes A10 nozzle is the Grand Canyon compared to a Delta A1. And the amount of flame produced by a standard Estes booster is just huge compared to what you get from a pinch of black powder (see previous pic). As for scraping out the sustainer nozzle, I know a lot of folks do it, and some of my teammates think not doing so borders on lack of patriotism , but I've never found it necessary. My fear is that I will inadvertantly scrape a smidgen out of the clay nozzle itself, leading to off-center thrust. Probably not a realistic fear on Estes-sized nozzles but more probable on a Delta or Ultra. |
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Steve,
My talk will also include mention of various staging/clustering techniques, so you are not off topic at all! I very much appreciate the information... GH, I was wondering when you were going to weigh in. Hard to imagine you not commenting on any thread that includes mention of the B14 However, I do agree with you in that I miss those motors. A proper 18mm 3 stager is almost impossible without them.
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Up next: Under construction: Under repair: In finishing: Centuri Sabre clone In primer: In paint: Ready for decals: Bill Cooke NAR #31312 TRA #19705 SAM #0001 Huntsville, AL My rocket blog My rocket fleet |
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Vanel-
I had some comments above about the B14/B8.... On a nearly windless day, one could get away with a C6-0 to C6-0 to C6-7 flight in an astron Farside, but I would not try it with a Farside-X. Of course if the C5-0 still existed it would also be acceptable along with the B14 or B8 in the bottom stage of a 3-stager. The old 18mm Cox D8-0 was good too. If I was to build an Astron Farside now, I would just leave the first stage booster 24mm and use C11-0's or D12-0's in it. I used to like to fly my Old Astron Avenger on an A8-0 or B6-0 to B14-5 or B14-7 flight. Would liftoff slow and stage low, then crazily take off like a shot when the B14 ignited. Was neat for school demos too.
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When in doubt, WHACK the GAS and DITCH the brake !!! Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't ! Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY. ALL systems are GO for MAYHEM, CHAOS, and HAVOC ! |
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GH, Thanks for that nice explanation. I could never figure out what anyone would use a B14-7 for. Makes sense, and sounds fun. Steve |
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Bill, Impressive list. Any listings for the first date and person to gap stage 5 to 5 to 1 over 10.5 inches twice on the same flight? Does it HAVE to be at a NAR NARAM launch to count in the record books? I think Verna made her first successful 5-5-1 flight back in 2004 (I think) but I would have to dig to get an exact date. I do know it's been done since by someone at a NARAM, I think the following year or maybe 2. Her first successful Saturn V 5-5-1 flight was at the BRB field in Birmingham on a Tuesday or Wednesday afternoon and was witnessed by then NAR 665 pesident Ron Witherspoon, and me & my son. Like I said I may be able to come up with the exact date. We just never thought about getting some kind of official recognition for it. The actual liftoff photo is on our site on the Bad Girl page. Randy www.vernarockets.com |
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Hi Randy!
There are statements about large staged clusters, but nothing very specific as to date/launch. However, I am sure that there were staged clusters with a fair number of motors by the mid-70's, especially with the advent of flashbulb ignition. The staging of Saturns was discussed in at least two MR/AS articles starting with Gary Cole's article in the Dec 1976 MR issue; also Bill Dye's article in American Spacemodeling, July 1986. It also featured a 5 motor cluster in the 1st stage. I am very impressed by Verna's accomplishment - I have never built or flown a model with a clustered 1st and 2nd stage, much less a Saturn. I wish I had seen it launch!
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Up next: Under construction: Under repair: In finishing: Centuri Sabre clone In primer: In paint: Ready for decals: Bill Cooke NAR #31312 TRA #19705 SAM #0001 Huntsville, AL My rocket blog My rocket fleet |
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Bill,
Thanks for the reply. As always I should have asked Verna if she had any notes. She used parts from 2 different 2157 kits over the 4 flights, mostly the flimsy fins. If she did it again she'd use the Sirius resin fins on the first stage. Flight results notes from her notebook 4 flights total: 4-27-04 All engines of 1st stage - free fall but no damage. Got 2 of 2nd stage, 1 of the 2 chutes brought it down nicely. 3rd stage seperated from the burn thru but did not light. Slight damage to 3rd stage paper wrap. Easily repaired. Slight damage to 3 of the vaccuform fins, easily repaired. Flown at strip mine in north Jefferson County, just us. 9-4-04 All 5 first stage, all 5 2nd stage - nice kick at staging but still missed 3 rd stage engine again and no chute. 3rd stage vaporized on impact,. Repaired 2 fins of first stage. Flown at BRB 665 field in North B'ham with our son and Ron Witherspoon. 11-17-04 All 5 of 1st and 2nd stage recovered no damage. GOT the 3rd stage this time! Very long walk to recover. Drifted almost to the north tree line about 600 yards. NO Damage! She credits complete success to using slightly more Scotch between 2nd & 3rd stages. 100 % success! Witnessed by Ron Witherspoon and our son. 3-12-05 All 5 of 1st stage, 4 of the 2nd stage but missed core engine so 3 rd stage no chance to light. Recovered missing 2 fins of the 1st stage, second stage drifted down nicely no damage. 3rd stage tumble deployed the chute, no damage. Witnessed by Ron Witherspoon. Rocket repaired for static display. So it took 3 attempts to get it right once but she did get it. It sits ready to go right now, but I doubt she'll ever fly if again. She would tell you that "itch" has been scratched. Maybe if one of the grandkids asked her... she might. ; ) Randy www.vernarockets.com |
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