#1
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Saturn 1b scratch build 1:70 discrepancy
I'm having a little trouble with my scratch build on this project, and I seek the help of those in the know. My problem is that starting with tube sizes from estes k29, the bottom bt101 is 2 .78" but according to George Gassaways drawing the same section of tube is 1.98". So which is the correct measurement?
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#2
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If you are building an Estes clone then the taller ring is correct. I think they did this to give the fins a little better protection. If you are building a true scale model, then George’s measurement is correct.
Estes model was a semi-scale model with larger fins also. So if you are going for true scale, then you will have to change the fin size and a few other things from the old K29 kit plans. Unless you are really stuck on true scale, go with the Estes - SEMROC plans. It will look better and fly better.
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======================= If the Sky is the Limit, then, why is there Footsteps on the Moon? ======================= Last edited by Flash : 08-19-2021 at 05:11 PM. |
#3
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Flash nailed it.
For those wondering about my drawing(s), here is the page link: http://www.georgesrockets.com/GRP/P.../Saturn-IB.html Based on NARTS drawings, other NASA sources. And NASA photos plus my own photos of the IB at Ardmore Alabama, and the interstage adapter that used to be at the US Space & Rocket Center before the tourist gimmick thing inside of it caught fire and burned (I do not know if it was scrapped or moved out of sight after that. IIRC it was not there when I visited in March 2019). A Saturn-IB with Scale sized fins, needs for the CG to be about at the middle of the interstage adapter. The more aft of that, the greater the odds it may go unstable. Notably the Centuri 1/100 kit, and Cox kit had more scale-sized fins.
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#4
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I much prefer scale-size fins on scale kits.
If it needs 8oz of lead shot/epoxy mixture in the nose and a 29mm F to fly safely, fly the darned thing on a F motor.
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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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