#1
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B14 *sugar* motors...
Hello All,
With the recent discussion of B14 motors, it made me curious about the possibility of "roll your own" B14 motors using the sugar/potassium nitrate propellant, which amateur rocketeers have used for many years, even for large sounding rocket-size vehicles. (One such group, "Sugar Shot to Space" [see: http://sugarshot.org/index.html ], is developing a sugar rocket to fly 100 km high.) I was surprised to find that the sugar propellant has a higher specific impulse (115 - 130 seconds, see: http://aeroconsystems.com/tips/Suga...or%20Design.pdf ) than black powder, whose specific impulse is 82 seconds (see page 19 of "Forty Years of Model Rocketry: A Safety Report" by G Harry Stine here: www.nar.org/pdf/40years.pdf ). Also: Sugar rocket motors typically use core-burning propellant grains. These include "The Incredible Five Cent Sugar Rocket" (see: http://servv89pn0aj.sn.sourcedns.co...PPR_Zine_91.pdf ), whose propellant is "de-rated" by including sulfur in its recipe. Since the propellant is loaded into the motor case in a semi-solid state, drilling the core would be unnecessary. Given the higher (than black powder) specific impulse of the sugar/potassium nitrate propellant, making B14-0 booster motors would not be difficult. Even single stage and upper stage B14 sugar motors with black powder delay and ejection charges would be possible, as "The Incredible Five Cent Sugar Rocket" pamphlet shows how to equip the small (about Estes mini motor size) sugar motors with delay and ejection charges. I hope this information will be helpful.
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Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see: http://www.lulu.com/content/paperba...an-form/8075185 http://www.lulu.com/product/cd/what...of-2%29/6122050 http://www.lulu.com/product/cd/what...of-2%29/6126511 All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com. NAR #54895 SR |
#2
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At our test site in Mojave one guy consistently does sugar motors. The ones I saw this month were reloads for AT 54mm hardware. These loads run about 4-5 seconds with heavy white smoke. His goal is to run steady pressures to not trigger the high burning rate exponent of sorbitol (sugar) motors.
A 18mm motor is likely to have a considerably shorter burning time, on the order of (0.1875/0.5875=0.319 * 4 =1.27) 1.27s. It would require a star or finocyl geometry to achieve the shorter burning time while maintaining burning time consistency. Tech Jerry |
#3
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Quote:
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Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see: http://www.lulu.com/content/paperba...an-form/8075185 http://www.lulu.com/product/cd/what...of-2%29/6122050 http://www.lulu.com/product/cd/what...of-2%29/6126511 All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com. NAR #54895 SR Last edited by blackshire : 05-23-2013 at 01:59 AM. Reason: This ol' hoss done had to correct a typo. |
#4
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These motors sound good to me.
Quite frankly I would like to see the NAR safety code changed to allow this sort of experimentation by ANYONE with absolutely ZERO cert level required. (Actually I would like the safety code SCRAPPED completely and never mentioned again) I would completely eliminate the 'no motor modifications that are not authorized by manufacturer' rule in a HEARTBEAT. Rocketry can be dangerous. Those that don't like it should be free to choose not to PARTICIPATE but should have to suck it up and just keep their traps shut otherwise. Don't like to play in that sandbox ? Fine, but otherwise STH up. My one-word answer to those that don't like it is the same as always- TOUGH.
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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 ! |
#5
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Quote:
Russian and Eastern European contest fliers--who frequently used *hand-pressed* black powder motors--commonly drilled holes in ejection charge caps (definitely a "NO-NO" in these parts) to make certain that they would get full-strength ejections to deploy their models' recovery systems instantly (a big matter in parachute- and streamer-duration contests, where a fraction of a second wasted in deployment can mean losing). In addition: It should be remembered that the first model rocket motors were also -amateur- rocket motors, which were hand-pressed by Orville Carlisle...who was a shoe salesman, *not* a professional rocket engineer or, indeed, an engineer of any kind!
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Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see: http://www.lulu.com/content/paperba...an-form/8075185 http://www.lulu.com/product/cd/what...of-2%29/6122050 http://www.lulu.com/product/cd/what...of-2%29/6126511 All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com. NAR #54895 SR |
#6
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You bring up some valid points, however you have a bit of horse sense and maturity behind the reasoning and logic. The problem is that you have to first remember who model rocketry's target audience was back then, and second remember that the very thing they (Model Rocketry's founding fathers) wanted was to keep the government out of it. Taking the latter first, making the hobby self regulating was considered far superior to the alternative of having GH's gubmint getting involved and setting up fees and permits and etc. There were quite a few "basement bombers" who were getting injured or causing damage. The far most dangerous part of the hobby was the motor manufacturing process (besides, this way they could be insured of a residual income). So make it look regulated to the gubmint legal boys (who appear only to be satisfied by wordy legalese type documents) and the gubmint will stay out of it. Get the gubmint's unofficial blessing, (see it's safe, the fire marshals have approved our safety code) and you can market it more easily to nervous Nellie mothers, who will allow there precious sons to go out and launch rockets. As to the first point, it is those sons (10 and up? maybe a bit younger) that these rockets were targeting for sale. It scares the beejesus out of me to think of someone out there at that age, with GH's mentality (but not his knowledge) and attitude toward safety experimenting on engine loads. There is no sure way to separate the wheat from the chaff in this matter (unless you're willing to allow more regulation into the hobby by having another certification status created, which will only open Pandora's box). Imagine, if you will, that 2% of rocketeers made their own and suffered some sort of problem (burning down the house, blowing off a thumb, etc.). I doubt our hobby would ever have hit the numbers it has if that were the case.
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Bernard J. Herman Ohio RLS Starport Sagitta Rockets email bherman@sagittarockets.com NAR # 97971 SR What's your idea on the best way to change Washington D.C.? Let us know at the Cantina Sagitta Cantina We're looking for a few good Catos, please tell us about any you may have had. Survey of Anecdotal Malfunctioning Engines or S.A.M.E. |
#7
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All of your points are valid. "Amateur rockets" in those bad old days were usually pipes or CO2 cartridges that kids stuffed full of match heads....often with permanently life-altering--and life-ending--consequences. The zinc dust/sulfur motors (which were also common in those days, and were even available as kits) were safer to operate, but very dangerous to make because of the propellant's "touchy" nature. With that said, though, I think there is a way to do experimental rocketry safely:
The Eastern European and Russian model rocketeers conducted their activities as part of government sponsored and organized clubs, so even those who pressed their own black powder motors and drilled ejection charge caps for "snappier" deployments didn't do so without the proper training and supervision. I don't advocate government sponsored and organized rocket clubs, but what John Wickman and some others (such as the "Rocket Ranch" motor-making training program) do is pointing the way to how this could be done on a larger scale. The motors are made in order to achieve a chosen thrust/time curve, and the "final exams" are instrumented static firings and flight tests. Also: Using propellants other than black powder would be much safer and would provide greater impulse in such motors. The sugar/ammonium nitrate propellants are powerful yet safe to mix and cast. The "Rocket Ranch" program teaches people how to make composite propellant motors, and John Wickman's students use his PSAN (Phase-Stabilized Ammonium Nitrate) solid propellant, which requires no vacuum de-airing of the mixed propellant and can be mixed safely using ordinary equipment before being cast into the PVC pipe motor cases. Hybrid rockets--which provide great scope for experimentation with fuel grain compositions, grain shapes, injector designs, and different oxidizers and chamber pressures--would lend themselves very well indeed to experimental rocket programs. In addition: I'm not a TRA member, but I believe they have provisions for experimental rocketry. If the NAR and CAR approached this issue in a positive manner (not "We oppose this!" but rather "How can we help--and be helped by--such programs?"), they could help to produce the next generations of rocket engineers, whom the increasing numbers of start-up private space companies (as well as the legacy aerospace firms) could employ. Now: The age issue could be addressed by the adoption of common-sense (horse sense--thank you for mentioning that above!) guidelines. For example, students below the age of, say, 15 would have to be accompanied by a parent or guardian in a rocket-making program. As well: G. Harry Stine himself wrote in his book "Halfway to Anywhere: Achieving America's Destiny in Space" (which was about the DC-X project and SSTO spaceships in general) that younger engineers, who learned from computer screens instead of hands-on work while pursuing their degrees, are less able to visualize and design systems in three dimensions; he praised the DC-X project for encouraging this old-school hands-on training that he benefitted from. Through these rocket-making educational programs, tomorrow's rocket engineers can get the same kind of theoretical plus hands-on education that Stine advocated.
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Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see: http://www.lulu.com/content/paperba...an-form/8075185 http://www.lulu.com/product/cd/what...of-2%29/6122050 http://www.lulu.com/product/cd/what...of-2%29/6126511 All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com. NAR #54895 SR Last edited by blackshire : 05-25-2013 at 11:09 AM. Reason: This ol' hoss done had to correct a typo. |
#8
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It's not that I'm against making your own engines, it's just that I am for keeping the evil "gubmint" away from at least one thing I like to do. (and if you don't think they are into that other thing that we all like to do , then you haven't been paying attention ) I agree it would be nice to see more young brains being challenged and coming up with newer and better ideas in the power department, I just don't know where the balance would come from.
Perhaps, if has you say, some sort of oversight could be given on a non- governmental level, we could attain some sort of balance. I am just wary of that type of individual akin to an old childhood friend who use to ask me, "what if we attached three D engines to a mosquito...."? With someone whom has some knowledge and not a lick of horse-sense (your welcome), we could find ourselves in another lengthy legal battle. The problem is that too much of society at this time is willing to let a government not only watch over them, but allow that government to make decisions for them. Well before I start down another tirade and draw in that P.O'd character, I better end.
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Bernard J. Herman Ohio RLS Starport Sagitta Rockets email bherman@sagittarockets.com NAR # 97971 SR What's your idea on the best way to change Washington D.C.? Let us know at the Cantina Sagitta Cantina We're looking for a few good Catos, please tell us about any you may have had. Survey of Anecdotal Malfunctioning Engines or S.A.M.E. |
#9
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I heartily agree about the necessity to *avoid* attracting official attention. If a program was developed at the college level, perhaps with sponsorship from the aerospace companies (it could be part of a work-study program for students who would be potential new employees of the companies), that might be a gray path solution (a balanced solution). *Serious* younger people might also qualify to take part in such a program if they were NAR or CAR members and were recommended by their teachers; this could be similar to programs like one I participated in, in which I took courses in college algebra, college trigonometry, and college computer science (the "101-level" courses) while I was still in High School. But before any such experimental rocketry program is instituted, a lot of preliminary discussion and research would be in order, to avoid possible pitfalls and unintended consequences.
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Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see: http://www.lulu.com/content/paperba...an-form/8075185 http://www.lulu.com/product/cd/what...of-2%29/6122050 http://www.lulu.com/product/cd/what...of-2%29/6126511 All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com. NAR #54895 SR Last edited by blackshire : 05-26-2013 at 05:27 AM. Reason: This ol' hoss done had to correct a typo. |
#10
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The next pitfall to overcome would be the big "L", liability. A lot of your clubs and especially any publically funded institutional backer would be hard pressed to ante up. Too much possibility for a "no" man to use his power and make himself think how grand and significant he is. but that, too, is another story.
About the only way I see something like this becoming viable is through the private sector. Even then you still have to overcome the penny pinchers and bean counters.
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Bernard J. Herman Ohio RLS Starport Sagitta Rockets email bherman@sagittarockets.com NAR # 97971 SR What's your idea on the best way to change Washington D.C.? Let us know at the Cantina Sagitta Cantina We're looking for a few good Catos, please tell us about any you may have had. Survey of Anecdotal Malfunctioning Engines or S.A.M.E. |
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