I am back (well, sort of)

I am back (well, sort of)

Post by tai f » Fri, 02 Mar 2001 11:03:34



I did not come to rmr to discuss politics, or any connections whatsoever. I
come here to discuss rocketry, and seek expert's advise, especially on high
power  rocketry. I did not come here for flames, grammar lectures (I am not
writing a formal essay, if I am writing a formal essay or a reseme then I
will check spelling). there are newsgroup like alt.flame for people on
newsgroups to vent. I am about to undertake a level one certification, and I
am doing it on a H128 with a LOC EZI-65. There are still some construction
tips I need that I cant really get on AARG E-groups because not as many
people go there as people on rmr. Yes I enjoy the rocketmole contest (Thanks
Andrew!) and I can finally take my time off of computers, and move on to a
more useful hobby. At least I see the need for calculus, because I am taking
it now.

    As for bob kaplow, I am sorry if I have said something that may have
offended you, I usually talk informally on newsgroups, just like the way I
talk to a friend. I will try not to talk about fireworks or pyrotechnics on
rmr, I will leave that for rec.pyrotechnics, but I ask you please not to get
on my case in rec.pyrotechnics, since fireworks is my other hobby, and I am
sure you guys have other hobbies right? I wont tell people to do something
dangerous or stupid and I will try and keep my flames if any at alt.flame,
is that okay with you guys?

Now as for advise I need, please tell me what is the best way to attach
shock cords to the rocket, the part with the motor mount in a high power
rocket? I dont really like attaching at the motor mount because the heat
might degrade the kevlar over time, but at the same time I want the mount to
be as  strong as possible. Not that I can't afford nomex sleeves, its just
that I don't want to put too much money in a rocket only to lose it to a
rocket eating tree. I keep hearing about quick links and it might just be a
great idea. can anyone share there level one story with me?

--

---
Tai Fu
NAR# 76089

 
 
 

I am back (well, sort of)

Post by Neil Tarasof » Fri, 02 Mar 2001 09:49:51


Dear Tai FOOL,

Where is my apology? You will get NO peace from Dancing Baby until
you get on your hands & knees & beg my forgiveness!

Neil Tarasoff

Quote:

> I did not come to rmr to discuss politics, or any connections whatsoever. I
> come here to discuss rocketry, and seek expert's advise, especially on high
> power  rocketry. I did not come here for flames, grammar lectures (I am not
> writing a formal essay, if I am writing a formal essay or a reseme then I
> will check spelling). there are newsgroup like alt.flame for people on
> newsgroups to vent. I am about to undertake a level one certification, and I
> am doing it on a H128 with a LOC EZI-65. There are still some construction
> tips I need that I cant really get on AARG E-groups because not as many
> people go there as people on rmr. Yes I enjoy the rocketmole contest (Thanks
> Andrew!) and I can finally take my time off of computers, and move on to a
> more useful hobby. At least I see the need for calculus, because I am taking
> it now.

>     As for bob kaplow, I am sorry if I have said something that may have
> offended you, I usually talk informally on newsgroups, just like the way I
> talk to a friend. I will try not to talk about fireworks or pyrotechnics on
> rmr, I will leave that for rec.pyrotechnics, but I ask you please not to get
> on my case in rec.pyrotechnics, since fireworks is my other hobby, and I am
> sure you guys have other hobbies right? I wont tell people to do something
> dangerous or stupid and I will try and keep my flames if any at alt.flame,
> is that okay with you guys?

> Now as for advise I need, please tell me what is the best way to attach
> shock cords to the rocket, the part with the motor mount in a high power
> rocket? I dont really like attaching at the motor mount because the heat
> might degrade the kevlar over time, but at the same time I want the mount to
> be as  strong as possible. Not that I can't afford nomex sleeves, its just
> that I don't want to put too much money in a rocket only to lose it to a
> rocket eating tree. I keep hearing about quick links and it might just be a
> great idea. can anyone share there level one story with me?

> --

> ---
> Tai Fu
> NAR# 76089


 
 
 

I am back (well, sort of)

Post by Mad Scientis » Fri, 02 Mar 2001 11:33:50


Tai,

I ran into the same situation.  My solution was to buy a piece of cable from
Pratt hobbies.  It's  a 6ft 160 lb test steel cable attached via quicklink
to the motor mount.  I also added a nomex heat shield.  Total upgrade, $17 I
think.  Good luck on your attempt.

--
Happy Smoke Trails to You!

Mad_Scientist

Take out the garbage to reply by email.

Quote:
> Now as for advise I need, please tell me what is the best way to attach
> shock cords to the rocket, the part with the motor mount in a high power
> rocket? I dont really like attaching at the motor mount because the heat
> might degrade the kevlar over time, but at the same time I want the mount
to
> be as  strong as possible. Not that I can't afford nomex sleeves, its just
> that I don't want to put too much money in a rocket only to lose it to a
> rocket eating tree. I keep hearing about quick links and it might just be
a
> great idea. can anyone share there level one story with me?

> --

> ---
> Tai Fu
> NAR# 76089

 
 
 

I am back (well, sort of)

Post by LeRoyc » Fri, 02 Mar 2001 11:43:24


Hi Tai, glad you found some time to get back to rockets, I use a 1/16 inch
steal cable attached to the eye bolt on the motor mount, the cable has a loop
at the top and I run this to about two inches from the top of the body tube so
there is room for a quick link, the top of the link is about an inch below the
top of the body tube and attach a one inch flat or tubular nylon strap to the
link to prevent a zipper, some times I use the nylon strap in a long lenth or
sometimes I attach bungee cord, depends on how much room there is in the tube,
this I learned from my first Aero tech kit when the shock cord broke on its
second flight, hope this helps, maybe some others have have some good idea's
too, good luck on your cert flight, Le
 
 
 

I am back (well, sort of)

Post by Ned Nassi » Fri, 02 Mar 2001 11:43:46



Quote:

> Now as for advise I need, please tell me what is the best way to attach
> shock cords to the rocket, the part with the motor mount in a high power
> rocket? I dont really like attaching at the motor mount because the heat
> might degrade the kevlar over time, but at the same time I want the mount
to
> be as  strong as possible.

Tai,

One option would to purchase a U-bolt and a couple quicklinks from the local
hardware store.  Mount the U-bolt to the top centering ring prior to gluing
to the motor tube.  Epoxy the nuts that***to the U-bolt.   You can then
use the quicklink to attach your shock cord to the U-bolt and replace if
necessary.  Shouldn't set you back more than $4-5.
Hope this helps.

Quote:
> Not that I can't afford nomex sleeves, its just

Well, I'm sure the underwear and vest set you back enough. :)

Welcome back.  Good question.

Ned Nassif
--
"There is a principle which is a bar against all information, which is proof
against all arguments and which cannot fail to keep a man in everlasting
ignorance - that principle is contempt prior to investigation." -  Herbert
Spencer

remove garbage in sig to reply

 
 
 

I am back (well, sort of)

Post by AkaZil » Fri, 02 Mar 2001 11:44:57


Aloha Tai,
Best of luck to you on your L 1 cert shot.
I would not worry about the Kevlar degrading due to being on the motor mount.
Fasten it to there, and be done with it.
Keep us posted on your progress,
Larry
 
 
 

I am back (well, sort of)

Post by Woody Mille » Fri, 02 Mar 2001 12:31:34


Quote:

> Now as for advise I need, please tell me what is the best way to attach
> shock cords to the rocket, the part with the motor mount in a high power
> rocket? I dont really like attaching at the motor mount because the heat
> might degrade the kevlar over time, but at the same time I want the mount to
> be as  strong as possible.

Depending on the bird, braided kevlar might be fine.  If you're like most people
I know, the L1 cert bird only get flown a few times (mine, once for the cert -
unpainted, and a second time with a paint job), atleast without redesigns,
etc...

The reason being, is that if you cert on a 29MM, then see some cool flights on
38mm reloads, you'll soon build something for 38mm, then a 54mm and so on...

The ubolt/eyebolt ideas in this thread make sense, but only if you can get to
them when the MT is in the airframe.. If not, just use bigger Kevlar!

PML and some RM used 1" TN from the MMT (PML may be using 1/2" in some), and in
one case, on a bird that had flown 20 times, and then lawndarted, and the entire
length of SC could be examined, there was no significant effect on the TN,
although motor eject was used for a number of the flights.......
--
Woody Miller
NAR 74701 L2
TRA  8539 L2
SSS
EARS
----------------------------------------------------------------
Alpha 40 Project website: http://www.users.qwest.net/~woody8
Superstition Spacemodeling Society: http://www.sssrocketry.org/
----------------------------------------------------------------

 
 
 

I am back (well, sort of)

Post by Tom Binfor » Fri, 02 Mar 2001 12:58:42



Quote:
> Tai,

> I ran into the same situation.  My solution was to buy a piece of cable
from
> Pratt hobbies.  It's  a 6ft 160 lb test steel cable attached via quicklink
> to the motor mount.  I also added a nomex heat shield.  Total upgrade, $17
I
> think.  Good luck on your attempt.

Overkill. Build it exactly stock, per the instructions. Mine lasted 46
flights before pranging when the ejection on the G500 never fired...

Tom

Quote:

> --
> Happy Smoke Trails to You!

> Mad_Scientist

> Take out the garbage to reply by email.

> > Now as for advise I need, please tell me what is the best way to attach
> > shock cords to the rocket, the part with the motor mount in a high power
> > rocket? I dont really like attaching at the motor mount because the heat
> > might degrade the kevlar over time, but at the same time I want the
mount
> to
> > be as  strong as possible. Not that I can't afford nomex sleeves, its
just
> > that I don't want to put too much money in a rocket only to lose it to a
> > rocket eating tree. I keep hearing about quick links and it might just
be
> a
> > great idea. can anyone share there level one story with me?

> > --

> > ---
> > Tai Fu
> > NAR# 76089

 
 
 

I am back (well, sort of)

Post by tai f » Fri, 02 Mar 2001 14:24:00


Do you know anything about hemp? some say its a good material or something
like that... maybe I could use it in a smaller rocket, and if I dont like it
I could smoke it.... :)

--

---
Tai Fu
NAR# 76089

 
 
 

I am back (well, sort of)

Post by Kevin Trojanowsk » Fri, 02 Mar 2001 13:14:24


Hemp burns too easily.  Ever been around hemp rope that's been near a
flame?

-Kevin

Quote:

> Do you know anything about hemp? some say its a good material or something
> like that... maybe I could use it in a smaller rocket, and if I dont like it
> I could smoke it.... :)

> --

> ---
> Tai Fu
> NAR# 76089

 
 
 

I am back (well, sort of)

Post by Cochran T » Fri, 02 Mar 2001 13:05:29



Quote:

>Hi Tai, glad you found some time to get back to rockets, I use a 1/16 inch
>steel cable attached to the eye bolt on the motor mount, the cable has a loop
>at the top and I run this to about two inches from the top of the body tube so
>there is room for a quick link, the top of the link is about an inch below the
>top of the body tube and attach a one inch flat or tubular nylon strap to the
>link to prevent a zipper...

I do much the same, but I dispense with the eyebolt-- an eyebolt isn't as
strong as steel cable unless it is really huge.  

Most hardware stores carry steel cable; if you look around you can usually
get stainless steel cable. Or order it from McMaster Carr--look at
http://www.mcmaster.com/ under wire rope, they have all kinds of it, and
lots of useful info.

1/8" cable is plenty big for an EZI (its breaking strength is 2100 pounds,
which is probably the strongest element of your rocket, but you don't want
to use anything smaller or it could slice through your rocket.  LeRoy's
1/16" cable is good for 500 lbs, which would be marginal for an 8 pound
rocket under severe deployment conditions).  1/8" SS cable costs something
like 28 cents a foot. Get a couple of crimp fittings (ferrules) for making
loops; these are sized for the cable you're using so get the 1/8" size.

Drill a 1/8" hole in the top CR, and reinforce with CA. Make a 2" loop at
one end of the cable with a ferrule or two.  Pass the free end of the
cable through it.  Cinch it tight around the MMT below the top CR.  Pass
the free end of the cable through the hole in the MMT. Make another loop
in the cable so that it falls short of the top of the BT.  Quicklink your
tubular nylon shock cord to that. Size the quicklink and the

BTW, keep the EZI-65 light--an H128 might be marginal in breezy
conditions.  Have you considered using an H180?

--tc

My opinions only.

 
 
 

I am back (well, sort of)

Post by Greg Cisk » Fri, 02 Mar 2001 14:11:45



Quote:
> rocket? I dont really like attaching at the motor mount because the heat
> might degrade the kevlar over time, but at the same time I want the mount
to
> be as  strong as possible. Not that I can't afford nomex sleeves, its just
> that I don't want to put too much money in a rocket only to lose it to a
> rocket eating tree. I keep hearing about quick links and it might just be

a

If you are going to loose the rocket after a few launches anyway, what does
it matter it the Kevlar *MIGHT* degrade over time? Chances are you won't
have enough launches for it to be an issue :-)

--


 
 
 

I am back (well, sort of)

Post by David Weinshenke » Fri, 02 Mar 2001 14:11:19


Quote:

> Depending on the bird, braided kevlar might be fine.
> If you're like most people I know, the L1 cert bird
> only get flown a few times
...
> The reason being, is that if you cert on a 29MM,

then see some cool flights on 38mm reloads, you'll
soon build something for 38mm, then a 54mm and so on...

Actually the PML X-Calibur that I used for L1 (on an
H128) is turning into a bit of a "workhorse"... it's
seen a couple of H180's and an H238 since then.

I've got an H220 and an H242 with its name on them.
So far it seems that the more power I give it, the
better it likes it.

-dave w

 
 
 

I am back (well, sort of)

Post by tai f » Fri, 02 Mar 2001 16:10:05


hehe, no wonder why someone could smoke it... but I bet it makes great
release string, used in helicopter rockets...

--

---
Tai Fu
NAR# 76089

 
 
 

I am back (well, sort of)

Post by tai f » Fri, 02 Mar 2001 16:12:46


Quote:
> Overkill. Build it exactly stock, per the instructions. Mine lasted 46
> flights before pranging when the ejection on the G500 never fired...

G500? do they make it? I think G500 would shread a EZI-65... after all one
of the rocketry joke is "you fly a EZI-65 on J350 and watch cardboard
confetti..."