HDTenEightyP/NetNews huggingface dataset:
From: jsivier@ux1.cso.uiuc.edu (Jonathon Sivier )
Subject: Re: 2 questions
Organization: University of Illinois at Urbana
Date: Thu, 5 Nov 1992 21:49:21 GMT

cdt@sw.stratus.com (C. D. Tavares) writes:

>Everybody.  Estes is STINGY with their shock cords.  Throw them out, and
>replace them with something at least 150% the length of the model (up to
>three feet).  Sewing elestic works nice.

Here's the rule of thumb that I use.  Use a shock cord with a length of 3 feet
for rockets up to 8 oz.  Add a foot for each weight increase of 8 oz. (i.e. 4
feet at 1 lb., 5 feet at 1.5 lbs., etc.)  I do this for rockets up to 4 lbs.
(10 feet of cord), then increase 1 foot/pound.  Also I determine the size of
shock cord from the weight of the rocket as follows.  Take the cross-sectional
area of the cord and multiply by 1000 and that is the maximum weight in ounces
of a rocket that cord should be used on.  I haven't done any tests of this, but
I intend to.  At least it gives me a place to start when trying to decide what
size and length of shock cord to use in a given rocket.

Jonathan

---------------------------------------------------------------------------
|  Jonathan Sivier               |  Secretary, Central Illinois Aerospace |
|  jsivier@ux1.cso.uiuc.edu      |  NAR #56437                            |
|  Flight Simulation Lab         |  Tripoli #1906
|  Beckman Institute             |  Home Address:                         |
|  405 N. Mathews                |    5 The Summit                        |
|  Urbana, IL  61801             |    Champaign, IL 61820                 |
|  217/244-1923                  |    217/359-8225                        |
---------------------------------------------------------------------------
Newsgroups: rec.models.rockets
From: billn@hpcvaac.cv.hp.com (bill nelson)
Subject: Re: 2 questions
Organization: Hewlett-Packard Company, Corvallis, Oregon USA
Date: Fri, 6 Nov 1992 01:25:46 GMT

jsivier@ux1.cso.uiuc.edu (Jonathon Sivier) writes:
: cdt@sw.stratus.com (C. D. Tavares) writes:
: 
: Here's the rule of thumb that I use.  Use a shock cord with a length of 3 feet
: for rockets up to 8 oz.  Add a foot for each weight increase of 8 oz. (i.e. 4
: feet at 1 lb., 5 feet at 1.5 lbs., etc.)  I do this for rockets up to 4 lbs.
: (10 feet of cord), then increase 1 foot/pound.  Also I determine the size of
: shock cord from the weight of the rocket as follows.  Take the cross-sectional
: area of the cord and multiply by 1000 and that is the maximum weight in ounces
: of a rocket that cord should be used on.  I haven't done any tests of this, but

The cross-sectional area in which units? Feet? millimeters? Microns? It makes
a sizeable difference in the allowed mass.

: I intend to.  At least it gives me a place to start when trying to decide what
: size and length of shock cord to use in a given rocket.

If you assume that the force on the cord doubles when the rocket weight is
doubled, and that you need twice as much shock cord to absorb this force
without snapping - then a 16 oz rocket would need 6 feet of shock cord (if
the 8 oz required 3 feet). A 2 pound rocket would then require 12 feet of
cord.  For larger rockets, you would want to consider using larger shock
cord - unless the rocket is quite long. I always make it a rule, with HP
rockets, to make the shock cord longer than the body tube length.

I have no idea which is the better starting point. I guess it partly depends
on whether you are competing - where every gram could make the difference
between winning and coming in last.

Bill
Newsgroups: rec.models.rockets
From: rprice@cbnewsg.cb.att.com (rodney.price)
Subject: rocket clubs in New Jersey
Keywords: rocket clubs in New Jersey
Organization: AT&T
Distribution: na
Date: Tue, 10 Nov 1992 21:29:30 GMT

I live in New Jersey, in Berkeley Heights, near the AT&T Bell
Labs at Murray Hill, and near Summit, Morristown, etc.  Does
anyone know of either an NAR or Tripoli sponsored club nearby?
Also, I've been unable to find any hobby shops selling engines 
bigger than D.  Where can I find one?

Rod Price
rprice@physics.att.com
Newsgroups: rec.models.rockets
From: jsivier@ux1.cso.uiuc.edu (Jonathon Sivier )
Subject: Re: Finishing Epoxy Question
Organization: University of Illinois at Urbana
Distribution: na
Date: Fri, 6 Nov 1992 22:50:03 GMT

hack@arabia.uucp (Edmund Hack) writes:

>I applied finishing epox to the fins of a few rockets I am constructing
>(a Quest Navaho and an Estes Pathfinder [which I got free from Estes in
>their buy 5 packs of engines/get a free rocket promotion]) and let them
>dry overnight.  To my surprise, the surface was quite rough to the touch
>when I checked them this AM.  Did I do something wrong?  What grit of
>sandpaper would be a good starting place to begin smoothing them?

    I think it is perfectly natural for it to be rough.  I think that just like
other filler/sealers the epoxy pulls up the balsa fibers and you end up with
a rough surface.  I usually use a light sanding with ~150 grit to get the
roughness out and then use 220 to get a smooth surface.

>I had decided to use finishing epoxy on them as an experiment and, since
>I'd like to use higher power motors in them, to strengthen the fins.
>Any other hints on using finishing epoxy?  Anyone know of a cheap source
>for brushes to use with it? I bought some "epoxy brushes" at the hobby
>shop where I got the epoxy, but they run 25 cent each.

    I use a rubber (plastic) spatula/scraper like you use for mixing and
scaping bowls in the kitchen.  It cost ~$1.00 and I've been using the same one
for almost a year now.  Finishing epoxy is so thin that it spreads very easily
and just be wiped off (before it hardens).  You can also get more than one use
out of a brush by cleaning it with dope thinner or alchohol.

Jonathan

---------------------------------------------------------------------------
|  Jonathan Sivier               |  Secretary, Central Illinois Aerospace |
|  jsivier@ux1.cso.uiuc.edu      |  NAR #56437                            |
|  Flight Simulation Lab         |  Tripoli #1906
|  Beckman Institute             |  Home Address:                         |
|  405 N. Mathews                |    5 The Summit                        |
|  Urbana, IL  61801             |    Champaign, IL 61820                 |
|  217/244-1923                  |    217/359-8225                        |
---------------------------------------------------------------------------
Newsgroups: rec.models.rockets
From: adrian@cs.hw.ac.uk (Adrian Hurt)
Newsgroups: rec.models.rockets
Subject: Re: 2 questions
Date: 9 Nov 92 13:41:25 GMT
Organization: Dept of Computing & Electrical Engineering, Heriot-Watt University, Scotland

In article <1992Nov9.133859.21866@cs.hw.ac.uk> adrian@cs.hw.ac.uk (Adrian Hurt) writes:
>
>I think something similar happens to my Hornet.  Disregarding Estes' colour
>scheme, I've painted mine overall light blue with a light grey nose cone,
>a bright yellow band around the top of the body, and similar yellow bands
>on each main fin.  When I recover it, I sometimes find the dent described
>above, and traces of yellow paint on said dent.

Correction: I find the paint _from_ the dent, _on_ the nose cone.

-- 
 "Keyboard?  How quaint!" - M. Scott

 Adrian Hurt			     |	JANET:  adrian@uk.ac.hw.cee
 UUCP: ..!uknet!cee.hw.ac.uk!adrian  |  ARPA:  adrian@cee.hw.ac.uk
Newsgroups: rec.models.rockets
From: j.cook@primerd.prime.com (C. James Cook)
Subject: Re: some questions on winter flying
Organization: Prime Computer R&D
Date: Fri, 6 Nov 1992 22:20:35 GMT

Just a few simple things:

1. Plastic becomes brittle when cold.  Bare ground becomes harder.
   If you have anything with single piece plastic fin units, don't launch
   on frozen lakes.  They land too hard (break).

2. CyanoAcrylate (CA) wants to shear off when cold.  Actually, many glues
   are affected this way to a lesser degree, but CA is a problem.  Usually
   you run into problems with kids that glue in their motor mount with 
   SuperGlue(TM) - it often breaks loose and slides up the body tube.
   Fins shearing off can also be a problem, but usually only on landing.

3. Black powder motors are more likely to cato when cold, particularly
   if they have been exposed to high temperatures.  Keep them warm in an
   inside pocket (or a "cooler" used to keep them warm) until time to use.

4. Batteries become weaker when cold.  Models take longer to get off the
   pad or don't ignite at all.  Make sure yours are fresh.

Good luck,
Jim
From: cdt@sw.stratus.com (C. D. Tavares)
Newsgroups: rec.models.rockets
Subject: Re: some questions on winter flying
Date: 6 Nov 92 19:36:32 GMT
Organization: Stratus Computer, Inc.

In article <BxAxz7.LnI@ux1.cso.uiuc.edu>, jsivier@ux1.cso.uiuc.edu (Jonathon Sivier ) writes:
> 
>    This winter will be the first one for our recently formed rocket club.  We
> intend to have launches on as close to a regular schedule as the weather will
> allow.  Aside from the weather are there any special problems with winter
> flying?  How does the cold effect the launch system, motors, etc.?  How about
> reloads?  Wasn't the freezing of the O-rings the cause of the shuttle disaster?
> If anyone has any advice I'd like to hear it.

Batteries don't last.  Engines can cato (flying them in low temperatures is
equivalent to their having been heat cycled "above" "normal" temperatures).
You drop lots of igniters (unless they gety embedded in your numb fingers, 
in which case you don't drop them).  Phone wire gets brittle, especially
if it's steel.  Parachutes "set" big-time.  Can't address reloads.

Sure you wouldn't rather hold some building sessions instead?
-- 

cdt@pdp.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: adrian@cs.hw.ac.uk (Adrian Hurt)
Newsgroups: rec.models.rockets
Subject: Re: looking for old model
Date: 5 Nov 92 14:33:03 GMT
Organization: Dept of Computing & Electrical Engineering, Heriot-Watt University, Scotland

In article <1992Oct29.211247.12193@primerd.prime.com> <J.Cook@ENS.Prime.COM> writes:
>In article <1992Oct29.170439.8733@cs.hw.ac.uk> adrian@cs.hw.ac.uk (Adrian Hurt)
>writes:
>
>>			Among the engines marked as a Series II is the
>>legendary C5-3; this note probably has something to do with that engine's
>>reputation.  But the 1/2A6-2 and B8-5 are also marked as being Series II.
>>Do they share the C5-3's poor record?
>
>Not that I know of.  While I don't have a catalog with thrust curves in front
>of me, either:
>(a) 1/2A6-2 & B8-5's thrust spike isn't as high

It is according to the catalogue, which gives both the B8-5 and the C5-3 a
peak thrust of 80 oz.  The Alpha Mini-book seems to confirm this; its
thrust curves for the two engines start off the same, but the B8-5 burns
out almost immediately after peaking, while the C5-3 drops to a lower
level and sustains it for a couple of seconds.

>(c) the casing isn't as prestressed as less is packed in there during mfg.

The casing seems to be the standard type which houses all C's, all B's and
most A's.

Perhaps the C5-3 got its reputation by catoing regularly in public, at big
meetings where no-one bothers with puny B engines. :-)

-- 
 "Keyboard?  How quaint!" - M. Scott

 Adrian Hurt			     |	JANET:  adrian@uk.ac.hw.cee
 UUCP: ..!uknet!cee.hw.ac.uk!adrian  |  ARPA:  adrian@cee.hw.ac.uk
From: msjohnso@donald.WichitaKS.NCR.COM (Mark Johnson)
Newsgroups: rec.models.rockets
Subject: Re: NARAM SUMMARY????
Date: 9 Nov 92 18:07:48 GMT
Organization: NCR Corporation Wichita, KS

cdt@sw.stratus.com (C. D. Tavares) writes:

>Note that most of the substitutions that I have caught in flight have been
>screwups.  People flying A B/G instead of B B/G because they thought they
>were supposed to (or, in earlier days, because they forgot what "Sparrow"
>and "Hawk" meant.)  Then there was Bob Sanford, who flew a 1/2A in B Egg
>Lofting because he looked at the engine fast and it said "6-2" on it.

>How did these get by the SCO?  The job is repetitive, and you're often 
>checking in two or three events simultaneously, all of which have different
>engine requirements.  The guy shows you an A3-4, you write "A3-4" on the 
>flight card, never noticing that it says "B Boost Glide" on it.  Or maybe 
>the guy has written "A Boost Glide" on it himself, when it's not pre-printed.  
>A card with that error on it will fail the nightly sort and be discovered;
>but the other could get all the way past the final results stage without
>anybody noticing what the engine line said.

>The points are:

>1) Substitution doesn't imply dishonesty; sanctions won't solve it.

Absolutely; I can't disagree with this one. I've caught honest mistakes
on a number of occasions, and flagged a few that I thought *might* be 
mistakes, such as Mike Micci's 1/4A RG, that boosted about 50% higher than
anybody else in the event (while I was RSO, anyway). I called for a return
on the model, thinking he might have accidentally gotten a 1/2A in it.
He hadn't, and we both went on our way.

The question still remains in my mind--for the rare cases where dishonesty
does exist, and I believe it does, how do we find it? What to do about it
isn't the problem, really...we already have the provisions for that.
[This is starting to sound like something that belongs on the ethics mailing
list].

>2) How likely is an SCO to keep even harder stuff straight?

Unfortunately, not very. I think, however, that we need to upgrade the
(geez, I hate this term) professionalism of the safety check officer position.
In most cases, as you point out, the SCO is the last link in pre-flight
safety. I didn't get to hear G. Harry's diatribe on kids doing safety (at
the Assn. meeting) but I believe there's a valid point in there somewhere.
The SCO's need to be more thorough than they generally have been for the 
past few years. I can't remember seeing anybody down-checked at a NARAM for
some time. Can you? However, I can remember lots of flights that should 
probably have been caught by the SCO, if the position was fulfilling its
intended function.  Too often, 'Safety Check' is really 'Paperwork check-in'.

-- 
Mark Johnson                          USnail: NCR Peripheral Products Division
E-mail:  Mark.Johnson@WichitaKS.NCR.COM       3718 N. Rock Rd.
Voice: (316) 636-8189 [V+ 654-8189]           Wichita, KS  67226
[Non-business email: 76670.1775@compuserve.com]
Newsgroups: rec.models.rockets
Newsgroups: rec.models.rockets

>jsivier@ux1.cso.uiuc.edu (Jonathon Sivier ) writes:
>
>   This winter will be the first one for our recently formed rocket club.  We
>intend to have launches on as close to a regular schedule as the weather will
>allow.  Aside from the weather are there any special problems with winter
>flying?  How does the cold effect the launch system, motors, etc.?  How about
>reloads?  Wasn't the freezing of the O-rings the cause of the shuttle disaster?
>If anyone has any advice I'd like to hear it.

In addition to the other comments you've already received:

plastic nosecones shrink in size quicker than paper body tubes when they get
cold. A snug fitting nosecone (at warmer temperatures) can become extremely
loose when launching in cold weather, resulting in nosecone separation during
coast. Check the friction fit closely and add masking tape as needed.

We just launched locally yesterday, it was ~30 degrees (F) and at least five
E thru G reloads were launched, all without incident. None that I know of 
were kept 'warm' in pockets prior to launch (probably a good idea, though).
At temperatures below 30 degrees, I'll either keep them in my pocket or just
stay home! 

{"Hey, is that a 29mm RMS in your pocket, or are you just happy to see me?"}

Bo Viger
Tripoli #1864
From: cdt@sw.stratus.com (C. D. Tavares)
Newsgroups: rec.models.rockets
Subject: RE: Competition Stratagies
Date: 10 Nov 92 17:30:12 GMT
Organization: Stratus Computer, Inc.
NNTP-Posting-Host: rocket.sw.stratus.com

In article <10NOV199210350427@vx.cis.umn.edu>, soc1070 writes:
> 
> That post on competition would maybe make a nice special section in
> the FAQ.

Actually, it probably belongs in American Spacemodeling.
-- 

cdt@pdp.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: jsivier@ux1.cso.uiuc.edu (Jonathon Sivier )
Subject: Re: 2 questions
Organization: University of Illinois at Urbana
Date: Fri, 6 Nov 1992 15:58:33 GMT

billn@hpcvaac.cv.hp.com (bill nelson) writes:

>jsivier@ux1.cso.uiuc.edu (Jonathon Sivier) writes:
>: cdt@sw.stratus.com (C. D. Tavares) writes:
>: 
>: Here's the rule of thumb that I use.  Use a shock cord with a length of 3 feet
>: for rockets up to 8 oz.  Add a foot for each weight increase of 8 oz. (i.e. 4
>: feet at 1 lb., 5 feet at 1.5 lbs., etc.)  I do this for rockets up to 4 lbs.
>: (10 feet of cord), then increase 1 foot/pound.  Also I determine the size of
>: shock cord from the weight of the rocket as follows.  Take the cross-sectional
>: area of the cord and multiply by 1000 and that is the maximum weight in ounces
>: of a rocket that cord should be used on.  I haven't done any tests of this, but

>The cross-sectional area in which units? Feet? millimeters? Microns? It makes
>a sizeable difference in the allowed mass.

Ooops!  Sorry, I use inches as the units.

>If you assume that the force on the cord doubles when the rocket weight is
>doubled, and that you need twice as much shock cord to absorb this force
>without snapping - then a 16 oz rocket would need 6 feet of shock cord (if
>the 8 oz required 3 feet). A 2 pound rocket would then require 12 feet of
>cord.  For larger rockets, you would want to consider using larger shock
>cord - unless the rocket is quite long. I always make it a rule, with HP
>rockets, to make the shock cord longer than the body tube length.

   But if you are increasing the cross-section and the length at the same time
then (hopefully) the shock cord volume is increasing at the same rate as the
rocket mass.

   For one of my winter projects this year I hope to do some experimenting in
this area.  If I get any results I'll post them.

Jonathan

---------------------------------------------------------------------------
|  Jonathan Sivier               |  Secretary, Central Illinois Aerospace |
|  jsivier@ux1.cso.uiuc.edu      |  NAR #56437                            |
|  Flight Simulation Lab         |  Tripoli #1906
|  Beckman Institute             |  Home Address:                         |
|  405 N. Mathews                |    5 The Summit                        |
|  Urbana, IL  61801             |    Champaign, IL 61820                 |
|  217/244-1923                  |    217/359-8225                        |
---------------------------------------------------------------------------
From: pfeiffer@nmsu.edu (Joe Pfeiffer)
Newsgroups: rec.models.rockets
Subject: Re: looking for old model
Date: 5 Nov 92 15:52:29 GMT
	<1992Oct23.212047.12004@cs.hw.ac.uk>
	<1992Oct24.201646.8952@fs7.ece.cmu.edu> <1992Oct29.170439.8733@cs.hw.ac.uk>
Organization: NMSU Computer Science

In article <1992Oct29.170439.8733@cs.hw.ac.uk> adrian@cs.hw.ac.uk (Adrian Hurt) writes:


   While I'm on the subject of the catalogue, it has an interesting note in
   its section on engines.  It says "Series II engines have semi-core-burning
   grain with large propellant burning area for high initial thrust with
   short thrust duration".  Among the engines marked as a Series II is the
   legendary C5-3; this note probably has something to do with that engine's
   reputation.  But the 1/2A6-2 and B8-5 are also marked as being Series II.
   Do they share the C5-3's poor record?

This brings up a question I've had for a while:  assuming the C5 has
the same total impulse as the C6 (my catalog isn't in front of me),
how can it possibly have a high initial thrust with short thrust
duration?  It has to have a longer duration, by definition.

-Joe.
Newsgroups: rec.models.rockets
From: j.cook@primerd.prime.com (C. James Cook)
Subject: Re: NARAM vs NSL
Organization: Prime Computer R&D
Date: Fri, 6 Nov 1992 21:54:21 GMT

soc1070                          writes:
> 
> The only disadvantage I can see to splitting NARAM and NSL is that
> both events will suffer from attendance drop. The thing that appealed
> to me about a single national event was the fact that you only had to
> travel once to "do it all" and you knew everyone would be there. Next
> year I hopefully will be able to travel to one event. Its too bad that
> at which ever event I make it to (NARAM or NSL) some of the people
> will have chosen to attend the other instead.
> 

I donno.  I haven't been a competitor at either of the two NARAMs I've 
attended, but I will still probably attend NARAM 35 because (a) NARAM
is closer than NSL this year and (b) they still do sport launches, and
(c) I like the mix (both event types and people types).

J
<J.Cook@ENS.Prime.COM>
From: cdt@sw.stratus.com (C. D. Tavares)
Newsgroups: rec.models.rockets
Subject: Re: NARAM SUMMARY????
Date: 11 Nov 92 19:17:29 GMT
Organization: Stratus Computer, Inc.
NNTP-Posting-Host: rocket.sw.stratus.com

In article <53628@donald.WichitaKS.NCR.COM>, msjohnso@donald.WichitaKS.NCR.COM (Mark Johnson) writes:

> Unfortunately, not very. I think, however, that we need to upgrade the
> (geez, I hate this term) professionalism of the safety check officer position.
> In most cases, as you point out, the SCO is the last link in pre-flight
> safety. I didn't get to hear G. Harry's diatribe on kids doing safety (at
> the Assn. meeting) 

..which, by the way, is a violation of the Pink Book.  SCO's are deputy
RSO's, and as such, have to be Seniors or Leaders.

> but I believe there's a valid point in there somewhere.
> The SCO's need to be more thorough than they generally have been for the 
> past few years. I can't remember seeing anybody down-checked at a NARAM for
> some time. Can you?

I've been working the NSL table for years, so I couldn't say.  We sure as
hell downcheck people there.

> However, I can remember lots of flights that should 
> probably have been caught by the SCO, if the position was fulfilling its
> intended function.  Too often, 'Safety Check' is really 'Paperwork check-in'.

Of course, the last time I downchecked somebody at a NARAM, it turned into
a minor scandal.  Some A Divisioner came up with a glider and a B6.  I told
him that a B6 would rip the wings off his glider, but if he could find a
B4, I would let him through.  Well, he couldn't find a B4 and never came
back.  That Association Meeting, everyone was treated to a tale by the kid's
mother of how kids were being turned off to the hobby by check-in officers
who took all the fun out of flying.  And nobody said a damn thing in defense
of the SCO.  This year, there was all this bitching about how safety officers
were being too EASY on people.  As always, people get the government they 
deserve.  Nobody's going to volunteer to be the scapegoat.
-- 

cdt@pdp.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: cdt@sw.stratus.com (C. D. Tavares)
Newsgroups: rec.models.rockets
Subject: Re: 2 questions
Date: 6 Nov 92 19:10:06 GMT
Organization: Stratus Computer, Inc.

In article <19921106073243.Roger.Wilfong@umich.edu>, Roger.Wilfong@umich.edu (Roger Wilfong) writes:
> And not to be forgotten are Mac Donald's Happy Meals (Apogee's former editor, 
> Bob Hegwood, coined the name "Kaplow's Disease' to describe the 
> uncontrollable urge to fly plastic food containers).  Bob claimes that he 
> got the idea at a NARAM that included PMC as an event.  There were so few 
> entries that he figured he could place in the event by just entering.  
> MacDonald's Happy Meal came in a plastic flying saucer at the time, and the 
> rest is history.

Yeah, but it's at least three administrations' worth of history.  It took
him that long to place in PMC using this strategy.
-- 

cdt@pdp.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