10-23-2008, 11:09 AM
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rocket dinosaur
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Join Date: Mar 2005
Location: My Old Kentucky Home
Posts: 1,184
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Quote:
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Originally Posted by Doug Sams
Terry,
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).
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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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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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