HDTenEightyP/NetNews huggingface dataset:
From: buzz@rsd.dl.nec.com (Buzz McDermott)
Subject: Re: Other reloadables besides Aerotech? (Re: Info. about solid rocket-
Organization: NEC America, Radio Software Dept
Date: Thu, 17 Dec 1992 19:16:17 GMT

In article <1992Dec16.202018.26648@aio.jsc.nasa.gov>, jackson@sn.jsc.nasa.gov writes:

|> As I remember ISP sells their reloads for commercial purposes
|> , to the military and industry, will they still be doing that?

Someone else posted earlier that the divestiture of Aerotech and ISP was in
part due to ISP's desire to concentrate on government & commercial customers.

|> Rumor has it that Aerotech is intensively making single use motors
|> again, G's,and B-class. Like old days, is this true?

Aerotech is apparently making a bunch of G's.  All of a sudden EVERYBODY has
tons of them in stock.  Does anyone know if the Rocketman 'G-whiz' sale is
still on?  $5.70/ea for G40/80's is CHEAP.

|> 'Course that means the old price problem again, but one could
|> still fly with out clustering. And maybe if the figures given
|> at LDRS that High Power Rocketry is in exponential growth
|> right now, well maybe there will be more single use competition
|> pricing.

Personally, I kinda like clustering.  Since Estes and NCR are both supposed
to start producing E/F/G motors (or is it just E & F's??) I would think we
should see some decent price competition by next year.  As for HPR, I 
understand that Vulcan has pulled out of consumer rocketry (was that rumor
on r.m.r, earlier?) to concentrate on its commercial business.  That doesn't
leave very many players to compete.

================================================================================
= Buzz McDermott                Disclaimer: I speak for no one but myself, and =
= buzz@rsd.dl.nec.com                       anyone who listens to anything I   =
= NAR   13559                               have to say deserves whatever they =
= TRA    1785                               get!!                              =
================================================================================
From: billn@hpcvaac.cv.hp.com (bill nelson)
Newsgroups: rec.models.rockets
Subject: Re: Tripoli Legal fund
Date: 18 Dec 92 18:42:03 GMT
Article-I.D.: hpcvaac.1992Dec18.184203.23218
Organization: Hewlett-Packard Company, Corvallis, Oregon USA

barrett@add.itg.ti.com writes:
: 
:   However, this being America, we need to spend money in order for our
: Government to listen to us.  We are in desperate need of contibutions to
: our legal fund.  Please send any amount that you can afford to our legal
: fund.  I have made a contribution of $100 which I think is easily
: rationalized by amortizing it over a couple of years of enjoying my
: model rocket hobby.
: 
: Please send your contibutions to:
: 
:   Tripoli Legal Fund
:   Tripoli Rocketry Assoc. Inc
:   PO Box 339
:   Kenner, LA. 70063-0339
: 
: 
: We need to make a contribution to our counsel THIS MONTH, so try and get
: your check in the mail ASAP.

Thanks Stu, I just received my mailing the other day.

Your comments apply to ALL rocketeers - whether Tripoli, NAR or independent.
The rules we are fighting for will affect ALL rocket hobbyists. Please send
what you can, even if you do not belong to Tripoli. Your help in getting
some of the current restrictions lifted will be greatly appreciated by all
other rocketeers.

Bill
Newsgroups: rec.models.rockets
From: jackson@sn.jsc.nasa.gov
Subject: Re: Other reloadables besides Aerotech? (Re: Info. about solid rocket-
Reply-To: jackson@sn.jsc.nasa.gov
Organization: Organization, City, State, etc.
Date: Mon, 14 Dec 1992 21:03:29 GMT


>
>Because, from the experiences of the people who have used both, the
>Aerotech version is not as good a design. Apparently, it has problems.
>I have never used one, so cannot say myself. However, there a couple
>of people who have had a lot of reloadable experience have told me
>to avoid the Aerotech reloadable.
>
>Anyone else out there who has used both? Any comments?
.......................
 I have used both Aerotech and ISP (tho they are both one in the
same, so to speak, companies) for about a year now.
I must say I do like the ISP design a little better, but I
cannot just say why.
As might be expected, the ISP reloads are just bigger versions of
the RMS Aerotech reloads. Some details are different. 
I actually have not flown my RMS motors that much.
...
I must say I have had very good success with all the ISP 
B - reloads. I have flown H - K1100. And they fly great.
My only beef, because, I would like to fly altitude is the
short burn times on all the ISP motors. This is a lousy
thrust program if you are going for height, the v**2
drag kills you at low altitudes. 
It makes for a fun 'hard rocket flight'. If we had drag
racing against the clock (with accelerometers?) in high power
model rocketry, it would be great to see what people could do.
What mach numbers they could get. The high acceleration of the
ISP motors would be great for this.
(I have seen 'drag' racing with these motors, but people just
kind of eyeball the results. This is a case were not having accuracy
sort of kills the fun, for me at least.)
...
From: det@phlan.sw.stratus.com (David Toland)
Newsgroups: rec.models.rockets
Subject: Re: Exhaust Deflector Material Question
Date: 14 Dec 92 18:08:41 GMT
Organization: Stratus Computer, Software Engineering
NNTP-Posting-Host: phlan.sw.stratus.com

In article <1992Dec14.081911.1@travis.llnl.gov> massey@travis.llnl.gov writes:
>Greetings,
>	I'm looking for someone who has had first-hand experience, either good
>	or bad, with using 1/8-inch aluminum plate (6061) as a launch-stand 
>	exhaust deflector. For the launchers that I'm building, the planned 
>	deflectors are about 10 inches square and perpendicular to the launch
>	rod. Will there be a problem with burn-through or melting? At what 
>	engine size does this begin to be a problem?
>
>	Remember, I'm looking for first-hand experiences, not opinions.

I tried using 1/8" Al plate for deflector plates (both angled and oblique)
many years ago, with unsatisfactory results.  After a few flights with
heavier models (which take longer to scoot) I had deep craters and in one
case a burn through.  Also, the burn residues appear to be quite corrosive
to aluminum, especially when they pick up moisture from the air.  The
reaction stinks to high heaven (a good deal of H2S seems to be involved).

I have really had much better luck with steel, even thin steel cut from
a coffee can.

I don't have a record of the engines I used at the time, but they were
probably B's and C's.

-- 
--------------------------------------------------------------------------
All opinions are MINE MINE MINE, and not necessarily anyone else's.
det@phlan.sw.stratus.com   |  "Laddie, you'll be needin' something to wash
                           |  that doon with."
Newsgroups: rec.models.rockets
From: Roger.Wilfong@umich.edu  (Roger Wilfong)
Subject: Re: Exhaust Deflector Material Question
Organization: UofM Hospitals
X-Newsreader: FTPNuz (DOS) v1.0
Date: Tue, 15 Dec 1992 22:32:00 GMT

In Article <1992Dec16.130245@primerd.Prime.COM> "j.cook@primerd.prime.com (C. James Cook)" says:
> The problem with using metal blast deflectors is that the rocket flame
> impinging on the metal deflector is a strong oxidizing jet.  This is akin
> to an oxygen-acetylene cutting torch in which extra oxygen is introduced
> to literally burn away to cut it instead of merely melting it.
> 
> For a long lasting deflector look for something ceramic. You can optionally
> cover a metal deflector with large ceramic tiles.  At worst, get a hunk of
> "miracle board" - the concrete board now used in place of plaster board or
> blue board in bathroom tub and shower surround areas.
> 
 
The ceramic (bathroom) tile works well.  Andy Tomash glued one to his 
aluminum plate after the D-12 burned through it.  He has not experienced 
another burn through, and it cleans up well since the ceramic takes the 
brunt of the exhaust blast.  It's also pretty durable, I don't have 
direct experience with the blue board you refer to, but if it's like the 
fire rated dry wall, it won't stand up to a lot of wear and tear.
From: soc1070
Newsgroups: rec.models.rockets
Subject: Re: Piston Ejection
Date: 15 Dec 92 21:36:00 GMT
Organization: University of Minnesota CIS
News-Software: VAX/VMS VNEWS 1.41

In article <1gl7t1INNe3p@sixgun.East.Sun.COM>, mlm@arreaux.East.Sun.COM writes...
>Has anyone built and used rockets with piston ejection for parachutes? I'm building
>a Public Missiles Phobos and have concerns about residue forming on the inside tube
>from the ejection charge. It seems to me that residue buildup could cause too much
>friction on the piston unless you clean well after each use. Has anyone run into
>problems with this?
> 
>Thanks,
>Mike

You might try Ed LaCroix at Apogee Components (71441.1111@compuserve.com).
I know he has done quite a bit of work with piston ejection. He researched
it mostly as a method of avoiding the dreaded "zipper effect" or other
tube damage as a result of ejection. I wish I would have used this method
on my scale Iris, which i destroyed by over coasting it and zippering
the whole tube.

Basically, Ed's method used a piece of kevlar and a stage coupler. Take
a piece of heavy cardboard or wood and glue it over one end of the stage
coupler. Drill a small hole in the center of the wood large enough for
the kevlar to pass. Sand the wood/couple smooth so it has a good slide
through the tube. Drill four or five 1/8 - 1/4" holes in the side of
the coupler just under the piece of wood. Attach one end of the kevlar
line to the motor mount, and run the other end through the hole in the
coupler. Aligh the coupler so the holes extend just beyond the end of 
the tube and tie a knot in the kevlar. The idea is to let the coupler
slide along the kevlar until the holes are exposed to the outside, then
the knot stops the slide. Because the kevlar dosen't contact the tube 
wall, it won't slice it.

------
Tim Harincar				Millions long for immortality			
Central Minnesota 			who don't know what to do with
Association of Rocketry			themselves on a rainy Sunday 
soc1070@vx.cis.umn.edu			afternoon. -Susan Ertz
Organization: Doctoral student, Urban and Public Affairs, Carnegie Mellon, Pittsburgh, PA
Newsgroups: rec.models.rockets
Date: Sat, 12 Dec 1992 23:33:42 -0500 
From: Lawrence Curcio <lc2b+@andrew.cmu.edu>
Subject: Re: CPRESS Vocabulary

DISCLAIMER:
As I note in the program, I merely transcribed CPRESS from AMSPAM. I
take no responsibility for it. 

A chord is a width of the fin parallel to the rocket body (or, if you
prefer, parallel to the airstream). The ROOT CHORD is this width of the
fin at its root (i.e.; the length of the fin/body joint). The tip chord
is this length taken at the farthest distance on the fin from the body.

SPAN RIGHT ANGLE is the width of 1 fin, taken perpendicular to the body.
(Yes, I do know what a span is, but this is the width of a fin.)

FIN SWEEPBACK is the distance, parallel to the body, from the leading
edge of the fin at its root to the leading edge of the fin at its
farthest poind from the body.

LENGTH, NOSE TIP TO ROOT TIP is the distance, parallel to the body, from
the tip of the rocket's nose, to the leading edge of its fin at the root.

E____C
|     \
|       \
|         \
|D___B______\A________________________________________   F
                                                      \
                                                        \
                                                        /
______________________________________________________/

ROOT CHORD = AD
TIP  CHORD = CE
SWEEP BACK = AB
LENGTH, NOSE TIP TO ROOT TIP = FA

These terms (or similar ones) are described in STINE APPENDIX III pp
337-338 in my fifth edition. The variable names used in the program
correspond to those in the appendix and diagram. Note that the appendix
in STINE is correct (as far as I can tell) but STABCALC is not. (Neither
is RASP79E, for that matter.)

Best Regards,
-Larry C.
From: paul@taniwha.UUCP (Paul Campbell)
Newsgroups: rec.models.rockets
Subject: Re: Hello and finless tec
Date: 15 Dec 92 19:16:35 GMT
Organization: Taniwha Systems Design

In article <19921207132909.Roger.Wilfong@umich.edu> Roger.Wilfong@umich.edu (Roger Wilfong) writes:
- CDT> I've always though of doing a scale model of a WESTAR launched
-    > from a spin table.  Of course you could get mission points for the WESTAR
-    > if you didn't ignite the motor. :-)
-
-  A launcher must not impart to the model any velocity or 
-  change of momentum except that caused by the model rocket 
-  motor(s) contained in the model.

OK - here's how you do it, you use one motor, you tie it to the spin-table
like a catherine-wheel - when you ignite it it spins up the WESTAR which then
flies off the table - not having a motor to ignite it gets mission points
by failing from then on :-)

	Paul

-- 
Paul Campbell    UUCP: ..!mtxinu!taniwha!paul     AppleLink: CAMPBELL.P
Use up your Quayle jokes now while they're still good "Quayle for Pres. in '94"
     Q: Why is Marilyn Quayle like Marion Barry?
     A: They both suck a little dope.
From: cdt@sw.stratus.com (C. D. Tavares)
Newsgroups: rec.models.rockets
Subject: Re: Hello and finless tec
Date: 18 Dec 1992 23:31:02 GMT
Organization: Stratus Computer, Inc.
Distribution: world
NNTP-Posting-Host: rocket.sw.stratus.com

In article <1345@taniwha.UUCP>, paul@taniwha.UUCP (Paul Campbell) writes:

> - CDT> I've always though of doing a scale model of a WESTAR launched
> -    > from a spin table.  Of course you could get mission points for the WESTAR
> -    > if you didn't ignite the motor. :-)

Anybody who knows me knows this is a ridiculous attribution.  Me?  Scale?
-- 

cdt@rocket.sw.stratus.com   --If you believe that I speak for my company,
OR cdt@vos.stratus.com        write today for my special Investors' Packet...

Newsgroups: rec.models.rockets
From: Roger.Wilfong@umich.edu  (Roger Wilfong)
Subject: Re: Exhaust Deflector Material Question
Organization: UofM Hospitals
X-Newsreader: FTPNuz (DOS) v1.0
Date: Tue, 15 Dec 1992 17:10:00 GMT

In Article <Af=pz7S00WB2I7jGRe@andrew.cmu.edu> "Lawrence Curcio <lc2b+@andrew.cmu.edu>" says:
> 
> Aside from using coffee can lids in my youth, I haven't experimented so
> I guess I don't qualify to comment, but Hey! I got this dandy computer
> network and all... 
 
Naw.  Computer networks typically have too many holes in them to effectively 
works as a blast deflector.
 
> Try stainless steel. 
 
I think that will work alot better than a computer network.
 
On the serious side, I've seen aluminum burn through on a D-12 that was 1/2"
above it at ignition.  I have both stainless steel launch rods and aluminum.
The aluminum need to be cleaned all the time because of corrosion buildup.  
The stainless steel need cleaning too, but the buildup is not as fast.
 
As a general rule, I try and clean and oil my launch rods and blast 
deflectors after a flying session.
From: jackson@sn.jsc.nasa.gov
Newsgroups: rec.models.rockets
Subject: Re: Other reloadables besides Aerotech? (Re: Info. about solid rocket-
Date: 16 Dec 92 20:20:18 GMT
Reply-To: jackson@sn.jsc.nasa.gov
Organization: Organization, City, State, etc.

***********************************************************************
All of this is a bit of a mute point, right now.  My understanding (talking
to several different RMS distributors over the past week) is that Aerotech/ISP
is not making ANY more reloads, or RMS casings, until the DOT issues are
resolved. For a good update on the regulatory issues, read the article by
Pat Miller in the latest 'mini AmSpam' issue.  You probably won't see any
'Aerotech' high power casings for a while. (although I hope this is not
the case).
 
I and several others have found out over the past week or 10 days that casings/
motors for RMS systems are now rare.  There seems to be a good supply of
reloads but limited ways to get access to them.  If the DOT situation isn't
cleared up soon I bet reloads will become very scarce before the end of
winter.
 
Well, rocketeers, it's time to get back to work on your clustering skills!
With the current availability of G motors for $7/ea and under, a 3xG cluster
is a cost effective way to get in the equivalent of a 38/360 reload flight.
 
================================================================================
= Buzz McDermott             
***********************************************************************
.................
I guess the rumors that the reload mish-mash would be cleared up
before the end of the year are wrong.
...
Questions in my mind.
As I remember ISP sells their reloads for commercial purposes
, to the military and industry, will they still be doing that?
.....
Rumor has it that Aerotech is intensively making single use motors
again, G's,and B-class. Like old days, is this true?
..............
'Course that means the old price problem again, but one could
still fly with out clustering. And maybe if the figures given
at LDRS that High Power Rocketry is in exponential growth
right now, well maybe there will be more single use competition
pricing.
...............
From: billn@hpcvaac.cv.hp.com (bill nelson)
Newsgroups: rec.models.rockets
Subject: Re: Club Projects
Date: 11 Dec 92 19:00:41 GMT
Organization: Hewlett-Packard Company, Corvallis, Oregon USA

Roger.Wilfong@umich.edu (Roger Wilfong) writes:
:  
: I also don't know how they do it, but altimiters have worked on barometric 
: pressure in moving airplanes for decades.  I suspect that (as with wings) 
: Bernoulli effect is greatly over rated - that is while there is an 
: atmospheric vent(s), it is not sufficiently aerodynamic to produce a 
: significant vacuum.

The altimeter in an airplane is not really subject to the Bernoulli effect.
The static port is open to the cabin of the craft - except for high altitude
craft, which use some sort of static chamber. The unpressurized cabin or
unpressurized chamber is at ambient atmospheric pressure. This might not be
the case if the aircraft were making 30,000 ft/minute altitude changes.

Bill
Newsgroups: rec.models.rockets
From: billn@hpcvaac.cv.hp.com (bill nelson)
Subject: Re: Club Projects
Organization: Hewlett-Packard Company, Corvallis, Oregon USA
Date: Fri, 11 Dec 1992 23:39:58 GMT

Roger.Wilfong@umich.edu (Roger Wilfong) writes:
:  
: While airplanes do not typically perform 30,000 ft/minute altitude changes 
: (at least usually not +30,000 f/m), this speed (340 mph) is well with in the 
: range of many unpressurized aircraft.  While in thoery, I am familiar with 
: flying an airplane; in practice, I am ignorant of how many of the details 
: are implimemnted.
:  
: If Bernoulli is going to have an effect on lowering the pressure as a result 
: of velocity, the cabin pressure of an airplane traveling 340 mph in any 
: direction should be lowered by the same amount.  A rocket traveling at the 
: same speed, should be subjected to the same change in pressure due to its 
: motion as the plane.  As long as there is a sufficiently large vent in the 
: payload chamber (and that vent isn't attached to a venturi), the internal 
: pressure should be able to track the atmospheric pressure at least as well 
: as the cabin pressure in an airplane can.  

Exactly. From a posting by another person - apparently the manufacturer
feels than a 1/4 inch hole is enough. I expect that would depend on the
volume of the chamber - as well as the rate of altitude change.

: If this is the case, as long as Tim takes into account the pressure drop due 
: to Bernoulli effect, he should be able to correct for it.  Actually, I would 
: think that the investigation of Bernoulli effect on the altimeter would make 
: a good R&D topic.

I think it would make an excellent R&D project. 

Bill
From: cdt@sw.stratus.com (C. D. Tavares)
Newsgroups: rec.models.rockets
Subject: Re: Club Projects
Date: 11 Dec 92 17:46:18 GMT
Organization: Stratus Computer, Inc.
NNTP-Posting-Host: rocket.sw.stratus.com

In article <1992Dec11.082610.4385@netcom.com>, hage@netcom.com (Carl Hage) writes:
> I can't see how the altimeter would be accurate except at peak altitude.
> How can you get a shielded chamber that is open to ambient pressure?
> It seems to me that if there was an air passage to the inside of the
> rocket, the Bernoulli effect would lower the measured air pressure while
> the rocket was ascending.

Bob Parks claims that if you punch two or three holes in the payload section
instead of just one, this effect goes away.  I can neither confirm or deny 
this -- that's just what he says.
-- 

cdt@rocket.sw.stratus.com   --If you believe that I speak for my company,
OR cdt@vos.stratus.com        write today for my special Investors' Packet...
Newsgroups: rec.models.rockets
From: ntaib@silver.ucs.indiana.edu (Iskandar Taib)
Subject: Re: Piston Ejection
Organization: Indiana University
Date: Thu, 17 Dec 1992 16:57:34 GMT

In article <1992Dec16.013110.17594@aio.jsc.nasa.gov> jackson@sn.jsc.nasa.gov writes:

>Only problem I have had is with phenolic, they just dont take      
>stress normal to the airfraOnly air frame IDynacom fibreglass
>Blackwidow, but its a heavy dude. Will be trying the carbon
>fibre composites soon.

Just wondering. Some time ago there was a thread about kevlar
rockets and I mentioned vacuum bagging. Anyone try it yet?




-- 
-------------------------------------------------------------------------------
Iskandar Taib                          | The only thing worse than Peach ala
Internet: NTAIB@SILVER.UCS.INDIANA.EDU |    Frog is Frog ala Peach
Bitnet:   NTAIB@IUBACS                 !
From: cdt@sw.stratus.com (C. D. Tavares)
Newsgroups: rec.models.rockets
Subject: Re: Shelf life of engines?
Date: 11 Dec 92 17:43:57 GMT
Organization: Stratus Computer, Inc.
NNTP-Posting-Host: rocket.sw.stratus.com

In article <1992Dec9.095805.1@azcc.arizona.edu>, kgirodias@azcc.arizona.edu writes:
> A quick question! What is the shelf life of Estes rocket engines? Can they
> NOT be safely flown after a certain number of years?

Provided they have never been stored at above about 140 degrees, nor
stored in a very damp place (loosens the nozzle clay), their shelf life
is indefinite.
-- 

cdt@rocket.sw.stratus.com   --If you believe that I speak for my company,
OR cdt@vos.stratus.com        write today for my special Investors' Packet...
From: jackson@sn.jsc.nasa.gov
Newsgroups: rec.models.rockets
Subject: Re: Hello and finless tec
Date: 15 Dec 92 09:36:45 GMT
Reply-To: jackson@sn.jsc.nasa.gov
Organization: Organization, City, State, etc.


>
>Rule 5.5 - Momentum
>
>A launcher must not impart to the model any velocity or change of momemtum
>except that caused by the model rocket motor(s) contained in the model.
>
.....................
Then, .... that makes it sound like 'linear' momentum and not
angular momentum. Anyway one could not gain any advantage by
imparting angular momentum about the roll axis, except stability.
Would there be less drag on a spinning finless rocket?
...
Organization: Doctoral student, Urban and Public Affairs, Carnegie Mellon, Pittsburgh, PA
Newsgroups: rec.models.rockets
Date: Sat, 12 Dec 1992 10:12:21 -0500 
From: Lawrence Curcio <lc2b+@andrew.cmu.edu>
Subject: Re: Club Projects

I'm not an aerodynamicist, but I read the aeronautics list. There was a
recent discussion about altimeters. The concensus was that those based
on barometric pressure are accurate, at best, to about 50 feet. That's
usually reasonable, though I share concerns about response rate and
Bernoulli effect. Also, of course, you have to take into account the
elevation of the launch site.

I like the idea of the accelerometer because it gives potentially more
detailed information. Problem with that is that you have to assume a
vertical launch. Otherwise you need pitch and yaw accelerometers as
well. Still, it's something I've always wanted to do.