#51
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The C5 used to have a 2.1 sec burn time with a large kick off the pad then a reduced thrust long burn.
Had as muck kick as the B8, with just double the propellant. Now we can fly our old C5's again without filing under the "old motor test program"
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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, TURMOIL, FIASCOS, and HAVOC ! |
#52
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Quote:
It's not conjecture. NAR and FAI contest fliers have tested motors on test stands over the years, and that's where our anecdotal information comes from. But no one has published the data AFAIK.
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-Wolfram v. Kiparski NAR 28643 - TRA 15520 MTMA Section #606 President Last edited by astronwolf : 01-17-2020 at 05:30 PM. Reason: spelling |
#53
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Quote:
The new kits are all posted on the Estes website now. The diameters are listed under Technical Specifications. BTW, the Doorknob is 3" diameter.
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Bob S.A.M. # 0014 |
#54
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I’ll start a new thread but S&T maintains they basically don’t publish because the data is within tolerances of the original published test. I asked for the data and like before even when prodded they don’t answer the question. |
#55
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Quote:
People are going to want to buy two of these to build the two stage version!
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-Wolfram v. Kiparski NAR 28643 - TRA 15520 MTMA Section #606 President |
#56
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Quote:
This is interesting - I have a test stand I put together using equipment from Vernier, and have used it to successfully test a few motors. So I went to my motor stash and pulled out the following B6-4's: Date code Weight (grams) 8 12 69 16.59 (also has a greater nozzle diameter) 17F5 (5/17/75) 18.23 19K5 (5/19/80) 17.81 15W5 (5/15/92) 18.36 A052703 (5/27/03) 17.76 B180918 (9/18/18) 19.00 I have dug out the test equipment and hope to do the tests this coming weekend, weather permitting. I then will post the thrust curves for scrutiny. The attached shows a nozzle comparison, with the 1969 B6-4 on the left.
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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 |
#57
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Finally found the time with good enough weather to make the measurements - the attached graph shows the results.
Basically, the B6-4 peak thrust has decreased over time and the burn time has increased. Impulse has stayed roughly the same at 4.3 +/- 0.3 N-sec.
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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 |
#58
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That’s great, and very interesting. However there is no gaurantee a motor from 40 years ago performs today like it would 40 years ago. Last edited by 5x7 : 02-02-2020 at 09:34 AM. |
#59
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My 2020 catalog came in the mail today--direct from Estes. Yay!
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Never trust an atom. They make up everything. 4 out of 3 people struggle with math. Chemically, alcohol IS a solution. NAR# 94042 SAM# 0078 |
#60
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Hmmm, I've got to get that Mars Longship! It reminds me of the spaceship on the Josie and the Pussycats in Outer Space cartoon.
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Never trust an atom. They make up everything. 4 out of 3 people struggle with math. Chemically, alcohol IS a solution. NAR# 94042 SAM# 0078 |
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