#21
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Jerry, the actual types Robert announced this week are: 18 mm: A6-X, A10-X, B6-X, C6-X, D7-X, longburner: C3-P, D3-P 24 mm: C12-X, D18-X, E18-X, longburner E7-P 29 mm: E22-X, F22-X
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European Model Rocketry: http://www.europerocketry.com Modellraketen Info: http://www.modellraketen.com |
#22
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The nozzles remind me of Composite Dynamics, which were cast ceramic with a washer throat. The cases appear to be convolute kraft with phenolic or some other coating to add stiffness. I wouldn't be surprised if the burst pressure of the 24mm case is over 600 psia on a hydrostatic test. My ISP guess is based on the 24mm almost 60F being about 30g. At an ISP of 180, a 30g motor will have about 54 N-s delivered unless delay and ejection must be included in the mass (not true for USPS, true for CE) in which case it is likely to be closer to 50 N'-s. Threshold motors like this are the most instructive. So far in EU anything over 62.5g NEW is 1.3C which is silly, but that will only give him about 100 N-s or so with delay and ejection. In Europe 1.4S is 30g NEW. In USA NA-0323 (USPS) is 30g Propelling Charge Mass. It's not just a nit. Jerry Last edited by Jerry Irvine : 02-06-2012 at 04:07 PM. |
#23
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Unfortunatly not, there were no engine factsheets, thrust curves and so on. The only point was that the F will be less than 62 g to avoid US hazmat shipping.
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European Model Rocketry: http://www.europerocketry.com Modellraketen Info: http://www.modellraketen.com |
#24
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But 30g should still allow up to middle F's to be shipped without hazmat fees. The 62.5g limit was from the ATF (US gov't) and also the NAR's HPR threshold (per motor). But I don't think it was a shipping weight metric. Although it may be a Canadian specification; not sure. (FWIW, I think the NAR is in the process of eliminating the 62.5g single motor limit from their HPR limits and instead simplifying it to the current 125g total propellant weight limit.) Doug
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YORF member #11 |
#25
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NFPA 1125 2012 edition now in effect. http://www.nfpa.org/aboutthecodes/A...asp?DocNum=1125
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-Fred Shecter NAR 20117 (L2) Southern California Rocket Association, NAR Section 430 |
#26
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So, can you give us the Cliff's notes version? What do I need to change on my graph? (Besides adding a white background...) (If you right click then select "view image" you can see the text more clearly.) Thanks, Doug .
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YORF member #11 |
#27
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I would wait for some official change to the NAR MRSC. Please contact NAR (Pres or VEEP) and ask them about this.
But, the 2012 version of NFPA 1125 has the maximum propellant weight for a Model Rocket motor as 125 grams, but they can only be sold to adults 18 or over - just like reloadable motors. Quote:
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-Fred Shecter NAR 20117 (L2) Southern California Rocket Association, NAR Section 430 |
#28
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Just be thankful it wasn't another youtube or music link.
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I love sanding. |
#29
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http://www.nar.org/NARsandt.html
http://www.nar.org/SandT/docs/ST-MotorTestingManual.pdf NFPA 1122 is currently at the 2008 edition and the next edition (2013 to be released in only a few months) will match the new 1125 version 125 gram weight, so perhaps they are waiting for that?
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-Fred Shecter NAR 20117 (L2) Southern California Rocket Association, NAR Section 430 |
#30
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Quote:
http://www.youtube.com/watch?v=6ntDYjS0Y3w
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-Fred Shecter NAR 20117 (L2) Southern California Rocket Association, NAR Section 430 |
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