#61
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When I look at the outer (more aft) openings on these, they seem almost too perfect to be pressed. BTW, great pic! Also, this clearly shows what Roy was talking about regarding how narrow the deep section was. Doug .
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#62
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Doug,
I've been told( If I told you who told me then I'd have to kill myself..sorry) ....it's my understanding..... that the B16/B3/B14 were originally B.8 motors( with extra increments of pressed BP) that had their original nozzle pressed/formed. Then in a single step process the clay nozzle core and upper smaller core were drilled out using whats called a half round drill bit The B.8 motor was a direct decendent of the A.8 motor which was a direct descendent of the Carlisale A4 motor. If anybody remembers, the orignal C.8 motors were not anywhere near later C6 motors.... they were in the neighborhood of maybe 6-7 Ns. I suppose its possible that the "extra increment BP" B.8 and C,8 were one and the same or very close. terry dean
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#63
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absolutely beautiful pics Sean.... now, can you place those 3 against later B14 or B8/C5? What I really would like to see is a .406" iD B3/B14 against a .5" ID B14. Are the clay clores the same size? I just wanted to add that if you look at the diagras in the old estes catalogs of the internals of the B3/B14 they are completely misleading(probably by design) as the cores are no where near as deep as they should. They are indeed on the order of .4" as Roy pointed out..... Since the B.8 had a throat diamter of .107" and the core was maybe 1/16" to 1/8" in depth, the actual core being drilled out was maybe on the order of .375" total. The larger .1875 nominal clay core opening didn't go much beyond the clay nozzle length itself..... A design "feature" of the older Estes engines, as you can see in the 1959 Estes patent shows this concave top to the nozzle/propellant slug interface. You can also see this starting around the 68-69 Estes catalogs. This was done in conjunction with the small core in end burners to get that characteristic initial thrust spike.... If I had an older Carlsile original motor or Brown manufactured motor that I could take apart (blasphemy!) I'm pretty sure you would see a completely flat nozzle facinf the propellant; this is why the thrust spike was so much "shorter" in its thrust time curve. Plus the fact it had a 1:1 expansion ratio nozzle; ie a cylinder instead of an actual shaped nozzle like the later Estes motors, which was also a new design feature of the original Estes motors. terry dean
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"Old Rocketeer's don't die; they just go OOP".....unless you 3D print them. |
#64
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That jibes with this: The original Estes C motor, circa 1964, was available only in booster form, and was replaced in 1968 by a C6. The early C motor would have been a thick walled case, and that would explain why it was booster only - not enough room for delay, etc. Also, the "extra increment [of] BP" is consistent with what I've heard. My take is that would have still been necessary on the later, thin-walled versions (B14, et al). ... Contrary to my earlier statement, I think the extra BP is more to prevent premature burn-thru than to compensate for the BP lost in drilling. It's obvious from looking at SEL's pic that Roy was right about there not being much powder removed during drilling. Doug .
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#65
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doug: You are correct that Estes has always added an extra increment or two of Bp on its booster motors such that it acts as a burst diaphragm, which is what the delay train does in motors with delays. I'm attaching TR14,TR-15 and TR-18 which are the original NAR S&T reports on the original Estes Series I, Series 2 and C.8 engines. You will notice the total impulse of the C.8-0 is 1.5 lbs or 6.67Ns barely a C. Also shown are internal represnetations of the motors and the long core of the B3 is again exaggerated, probably on purpose. These reports where done and written in 1962-63 by none other than G. Hary Stine himself who was NAR S&T Chiarman during that time as well a being NAR President,etc. he wore a multitude of hats. something lese I am unclear in is whether or not Centuri actually ever made their own B14 or were all the Centuri B14 just relabeled Estes B14. Anybody know? terry dean
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"Old Rocketeer's don't die; they just go OOP".....unless you 3D print them. |
#66
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Point taken but from what I've seen on "How it's Made" there are a lot of surprising things that are run through metal detectors before they go out the door, so the technology is probably there... Definitely not cheap, but available... kick each motor through a metal detector as soon as it's done. There would be other methods available to ensure the integrity of the components as well, such as breakwires, etc. But as you said, profitability is a whole other issue... OL JR
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The X-87B Cruise Basselope-- THE Ultimate Weapon in the arsenal of Homeland Security and only $52 million per round! |
#67
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I volunteer. I will put together a team of guys to do it. We want to also make 24mm D40's. Jerry |
#68
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I wanted to clarify something I said in my B14 comments about the Clay core and upper inner core both being drilled in a one step process. This ONLY applied to the original B16/B3/b14 motors that had the .406 ID casing; when Estes changed the casing from .406 to .500" ID, they also changed the nozzle shape; the B14 that were created at this point and later used a formed clay nozzle core with only the upper inner core actually being drilled.
terry dean
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"Old Rocketeer's don't die; they just go OOP".....unless you 3D print them. |
#69
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Now i can finally build my Micro-Saturn-V without knowing it's a one-shot with B6-0-B6-0-MMX. the thread is here. If the reintroduced the 1/4A3-0 and the 1/2A3-0 I'd have a "backyard flier" (Actually, I live in the city. To us, a backyard flier is a Big Bertha with a MMX ).
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#70
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E dual egglofter
I hear an E15-7 is what to use but, afraid of such a long delay. Any comments? How about an E30-4? My rocket is 20.5 " long, and about 153 grams loaded. Second attempt @ dual eggloft duration. First rocket too underpowered and took a core sample. Thanks!
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