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  #31  
Old 07-23-2010, 10:01 AM
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Doug Sams Doug Sams is offline
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Quote:
Originally Posted by ghrocketman
I think the right most B14's in those pics are the "precursors" to the B8 motors that replaced them.
Functionally, those last produced "B14s" I theorize were actually B8's; I have some late B14-7's and I cannot tell ANY dimensional difference in them from the B8-7's from a year later even under magnified examination.
That's kinda how I'm thinking, too.

But note one key diff: The narrow bore B14, which looks much like the B8, is still deeper, 0.75" versus 0.6". It has the same depth as the bigger bore B14's.

OTOH, it could simply be the later B14 (in the pic) was formed on a pintle that had been worn down (eroded) by too many pressings, and then drilled. Or maybe the drill bit itself, assuming a two slope drill bit, had been worn down by too many drillings. (A bit with a long, narrow tip that also includes a wider cutter up the shank, sort of a like a bit in a countersinking mount, could be used to simultaneously drill the deep, narrow core while also widening and reshaping the nozzle. Such as bit could wear faster on the abrasive clay end thus resulting in the smaller nozzle openings while still maintaining the deep bore.)

But I like the precursor idea better

Doug

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  #32  
Old 07-23-2010, 11:05 AM
shockwaveriderz shockwaveriderz is offline
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http://www.forums.rocketshoppe.com/...achmentid=10757

3 b3- rocket engine cores from 1967 by SEL



also found this:

http://www.forums.rocketshoppe.com/...54&postcount=62


the B.8 (old designation) was of course a B4 (new designation) Although MMI sold at as a B6......


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  #33  
Old 07-23-2010, 11:14 AM
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I find that picture to be very Hypnotoad-esque.




Quote:
Originally Posted by shockwaveriderz
http://www.forums.rocketshoppe.com/...achmentid=10757

3 b3- rocket engine cores from 1967 by SEL



also found this:

http://www.forums.rocketshoppe.com/...54&postcount=62


the B.8 (old designation) was of course a B4 (new designation) Although MMI sold at as a B6......


Terry Dean
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  #34  
Old 07-23-2010, 01:13 PM
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My early B14 engines from '68 or '69 look almost exactly like those B3 nozzles that OBVIOUSLY have drilled cores.
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  #35  
Old 07-23-2010, 01:25 PM
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Quote:
Originally Posted by ghrocketman
My early B14 engines from '68 or '69 look almost exactly like those B3 nozzles that OBVIOUSLY have drilled cores.
They should. As I understand it, the only difference between the B14 and the B3 was the metric versus imperial units designation. 3*4.45~=14. At some point, the thin walled casings took over. Not sure how that may have affected things. But if the ID of the case is greater, then less depth of BP is needed to achieve the same volume of BP (~equating volume with impulse). So I wonder if the core had to be revamped somewhat to deal with that, to keep from breaking/burning thru too soon.

Doug

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  #36  
Old 07-23-2010, 03:35 PM
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Quote:
Originally Posted by Doug Sams
They should. As I understand it, the only difference between the B14 and the B3 was the metric versus imperial units designation. 3*4.45~=14. At some point, the thin walled casings took over. Not sure how that may have affected things. But if the ID of the case is greater, then less depth of BP is needed to achieve the same volume of BP (~equating volume with impulse). So I wonder if the core had to be revamped somewhat to deal with that, to keep from breaking/burning thru too soon.

Doug

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I had B3 motors with the thick walled casing (same as used in the classic 1/4A3, 1/2A6, A5 and B4 18mm motors). I flew them. They worked.
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  #37  
Old 07-23-2010, 08:47 PM
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Guys,

Can you give me an example of what you might have flown on a B14-7. I always think of the B14 as a heavy lift motor and I'm having trouble reconciling that with a 7 second delay.
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  #38  
Old 07-23-2010, 09:14 PM
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Quote:
Originally Posted by Gus
Guys,

Can you give me an example of what you might have flown on a B14-7. I always think of the B14 as a heavy lift motor and I'm having trouble reconciling that with a 7 second delay.


Estes recommended it as an upper-stage engine for the Apogee II, and the Delta when lifting the Camroc. For the Farside and Farside-X, they recommended the -6. Yes, they made a -5, -6, and -7!

Centuri was a bit more liberal in recommending the B14-7 for its kits, listing it for their small, ST-7 (like Javelin) or ST-8 (like MX774) kits, but *not* for their multistagers!
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  #39  
Old 07-23-2010, 09:24 PM
shockwaveriderz shockwaveriderz is offline
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Quote:
Originally Posted by Gus
Guys,

Can you give me an example of what you might have flown on a B14-7. I always think of the B14 as a heavy lift motor and I'm having trouble reconciling that with a 7 second delay.



This is an interesting question, Gus. I can remember in my first go-round with modle rocketry circa 1967-1972, that I had B14 motors........ But I really don't have any memories of actually using any. I was not (and still am not) a very good modeler, and once I figured that out (which was within the first 2-3 kits), I basically just read the Model Rocketry magazine and collected kits and engines at NARAM-12 and NARAm-13. I know for sure that I spent at least $500 each visit and brought a lot of stuff back but never built it and it sat in a strage shed until the late 70's or early 80's when my mom moved and threw it all away. She did keep the MR magazined and gave them to me years later.

In the 7th grade we had a rocketry "club: that consisted of a few people in the overall science club, and my neighborhood friends only came around to watch me launch and chase my rockets. They pushed the button sometimes but that was about it. There was no local hobby stores as I lived in a small rural town (pop. maybe 3,000) so I was basicially a lone rocketeer as a kid from 12-16.

Sorry to get carried away. I know from my memory that I had 2 rnage boxes stocked full of modle rocket engines of all types purcahsed between 67-72... I would estaimate at least several hundred easily.

Terry Dean
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  #40  
Old 07-23-2010, 09:46 PM
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Quote:
Originally Posted by Royatl
Estes recommended it as an upper-stage engine for the Apogee II, and the Delta when lifting the Camroc. For the Farside and Farside-X, they recommended the -6. Yes, they made a -5, -6, and -7!

Centuri was a bit more liberal in recommending the B14-7 for its kits, listing it for their small, ST-7 (like Javelin) or ST-8 (like MX774) kits, but *not* for their multistagers!



I flew the old B3-7 in my Centuri Javelin - what a neck snapper! Maybe that is the cause of the arthritis in my neck today
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