FSI F100 and E60 motors were pressed around a large-diameter pintle.
Not sure about the D18 and D20 though as those cores were MUCH smaller.

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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 !

I don't know for sure, but I know they had at least 7 rammings in the F7 and F100. They added some propellant and rammed it in, then repeated until they were done.

__________________
-Fred Shecter NAR 20117 (L2)
Southern California Rocket Association, NAR Section 430

I have seen some later B14's that looked more like B8's - they didn't begin to have the larger cores seen on the earlier B14's. It wasn't clear to me if this was due to worn out drills, substitution (ie, selling B8's as B14's before finally getting new cert's and name changes), or mislabelling.

(I posted a pic of the various B14 and B8 nozzles somewhere, but danged if I can find it now...) [Edit: It was on my old website, but I need to upload it to my new one.]

Doug

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YORF member #11

IIRC, that's the way some of the Chinese motors were done, creating a pulsing thrust. I havn't flown my D5's or long burn C6's yet, so I'm only going by memory of what has been posted here in the past.

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I love sanding.

I think there was a later (possibly Centuri blue or green casing era) version of B14 make with a deep tapered core rather than the core with two steps seen earlier. It was much deeper than the B8/C5 core.

__________________
-Fred Shecter NAR 20117 (L2)
Southern California Rocket Association, NAR Section 430

I have one of those blue-casing motors (a Centuri B14-7, Date Code: 110 1 73). Its nozzle is *very* wide and is almost cylindrical in cross-section, rather like the "nozz-hole" orifices in the Quest MicroMaxx motors. The tapered propellant grain void looks conical (it may be cylindrical for the upper 20% or so, but the foreshortened view makes it difficult to tell).

I also have an Estes B14-5 (Date Code: 21J5), whose nozzle looks like a B4's nozzle (going from memory, as I don't have any B4 motors on hand). The nozzle is considerably narrower than the Centuri B14-7's nozzle; it is a straight-sided cone that narrows down to a short cylindrical section. The grain void beyond is almost cylindrical, being a gently-tapered cone.

For comparison, a Centuri B8-5 I have (Date Code: 10l8? [the bottom of the third character wasn't printed]) has a nozzle only slightly wider than that of an Estes B6-4 (Date Code: 10 A 10). The grain void is conical, with perhaps the upper 10% - 15% being cylindrical.

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Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
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NAR #54895 SR

Here it is: (The dimensions are nozzle depth.)


And here's a close-up:



Doug

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YORF member #11

Thank you for posting these pix, Doug!

__________________
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

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.

__________________
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 !

here is a theory (based on nothing but a guess):

Motor manufacturers can change a design without recertification as long as there is no major change. Often a motor is redesigned because of a change in propellant (different sources of black powder) or a change in place of manufacture. Usually the new samples are submitted for recertification, sometimes with the same motor designation (like the Quest C6-5 made in USA, Germany and China). back in the 1970's they may have tweaked the B14 design and tried to keep calling them B14's, but then either decided to recertify them as B8 on their own or after the NAR told them to do so.

I still think there was a tapered bore version (deep large hole plus deeper tiny drilled cylinder) as well as a long tapered single bore version (like a B8 bore, but deeper).

Any photos or measurements of a 196's era English units B3 motor?

product be submitted for testing.

__________________
-Fred Shecter NAR 20117 (L2)
Southern California Rocket Association, NAR Section 430