#31
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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 |
#32
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I received a direct email from Garth about Shand after the CAR president forwarded him my email. I didn't ask if I could repost it, so hopefully he will add what he told me to this thread.
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I love sanding. |
#33
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Shand Inustries
I also see that Taras Tataryn, and Savario Prato have posted a lot about Shand Industries on YORF yesterday.
Any link to Canaroc industries, could be confirmed by contacting Roger or Dennis Lufkin via the Edmonton Rocketry Club. The reason I posted a comment on Facebook re Shand and Canaroc, was a discussion I had with Roger about thirty years ago when he showed me a bunch of Shand motors he had at the time. I did have an opportunity to fly some Shand B2's back in 1973 but unfortunately unlike Savario, I do not have any in stock. Shand was in business for only a couple years 1972-1973 then vanished, Canaroc was started in 1973, and their first motors, black powder, were made by AVI Astroport and were sold until about 1975/76 when Canaroc developed their own composite motors. Michael Ady from Calgary was Canaroc's motor guru, and the propellant formula was, to be expected, held as proprietary company info. The original Canaroc Composites were almost identical , in case material, nozzle material and thrust profile to the Shand motors. Hope that helps. Taras of course would have much more info on Canaroc/SMI history during the 1980's, again some of which he posted earlier in this thread. Also the information that Taras and Savario posted earlier re Shand is significantly more than what I have. I do have some additional printed material regarding Shand and will post once I go through my archives. Hope that helps. Garth Illerbrun CAR S04 L3 NAR 26894 L2 |
#34
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I had some B2 motors. They seemed to be the same chemical/ propellant as Jetex pellets.
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-Fred Shecter NAR 20117 (L2) Southern California Rocket Association, NAR Section 430 |
#35
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Ok, that is interesting. So, I am assuming they are not a typical AP-based composite propellant then? I was really wondering how they could get such long burn times from a ‘composite’ motor which, looking at the posted PDFs, has a fairly deep ported core design. Earl
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Earl L. Cagle, Jr. NAR# 29523 TRA# 962 SAM# 73 Owner/Producer Point 39 Productions Rocket-Brained Since 1970 |
#36
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Jetex pellets were allegedly Guanidine nitrate.
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-Fred Shecter NAR 20117 (L2) Southern California Rocket Association, NAR Section 430 |
#37
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Not allegedly, they WERE Guanidine Nitrate.
Someone in Britain was recently making them again, but I have no idea who would want that guff.
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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 ! |
#38
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There is nothing wrong with guanidine nitrate as a model rocket motor propellant; it is no less versatile than black powder. End-burning GN motors would produce lower acceleration (with longer burn times) for light- to medium-weight models, and would be outstanding for altitude contest models. Core-burning GN motors would give high thrust for shorter durations, for getting heavy and/or high-drag models up and moving, and: The only problem with guanidine nitrate (which modern packaging technology would easily make irrelevant) is that it is hygroscopic; that is, it absorbs moisture from the air. This makes old Jetex fuel pellets--unless they were stored in a very dry environment--hard to ignite, and it also sometimes results in uneven "combustion." (GN does not burn as a fuel/oxidizer mixture does, but instead decomposes exothermically, breaking down to yield an exhaust of mostly gaseous nitrogen and ammonia.) The packaging of the Jetex fuel pellets--metal cans with slide-off lids, and clear plastic blisters stapled to a backing card in a couple of places--didn't do much to maintain a dry-air environment, but: New-production Jetex fuel pellets--and guanidine nitrate propellant model rocket motors--could be packaged in a dry-air (or even dry-nitrogen) environment at the factory, in individual, tear-open foil or plastic pouches (or perhaps nozzle-sealing discs instead of pouches, for single-use GN model rocket motors; reloadable GN motors' fuel grains could be packaged in sealed pouches). The individual motors' (or fuel pellets' or propellant grains') pouches or sealing discs would be opened (or removed) only soon before use. If the weather suddenly changed at the flying field, opened ones kept in pressed-flat, sealed Zip-Loc bags would "keep" for quite a while if stored out of sunlight in a cool, dry place (and putting silica gel dessicant packs in the bags would extend this to months or even years), so that the guanidine nitrate fuel's hygroscopic characteristic would be rendered a non-issue.
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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 |
#39
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The guanidine nitrate (Jetex fuel) model rocket motors would be most interesting if one or more of you all (and/or the other principals you mentioned) produced them, particularly in average thrust/delay combinations not available from U.S. manufacturers. Another interesting propellant--which would provide the unique "after-burning exhaust plume" of double-base propellant (which would be ideal for many scale models)--is PSAN (Phase-Stabilized Ammonium Nitrate). Dr. Adolf Oberth (a son of astronautics pioneer Dr. Hermann Oberth) developed PSAN fairly recently, and a flight test of a PSAN-powered rocket at Wallops (see: http://wickmanspacecraft.com/psan-i/ ) shows its distinctive "after-burning" exhaust plume.
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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 |
#40
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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 |
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