LOC IV Nose Cone Attachment Q

LOC IV Nose Cone Attachment Q

Post by DLoga » Tue, 05 Mar 2002 08:14:06



I'm building this for my Level 1 attempt, and I'm using tubular nylon and
quick links for the shock cord.  I'd like to install an eye bolt for
attachment to the nose.  How do most of you do this?  I've thought of using
a hollow wall anchor (not a toggle bolt), but will the plastic hold up to
one of these?  It's the kind that spreads 4 metal "blades" out as you
tighten it, and is permanent once installed.  Any help would be greatly
appreciated.  I could probably use the stock attachment point, but I want to
make sure this thing is stout.  My motor of choice is going to be the H165
Redline.
Thanks, David
            NAR # 79313
 
 
 

LOC IV Nose Cone Attachment Q

Post by Joel Roger » Tue, 05 Mar 2002 08:54:33


You can cut the very bottom out of the nosecone and epoxy a bulkplate in
with the eyebolt already installed.

JR
77267
L1


Quote:
> I'm building this for my Level 1 attempt, and I'm using tubular nylon and
> quick links for the shock cord.  I'd like to install an eye bolt for
> attachment to the nose.  How do most of you do this?  I've thought of
using
> a hollow wall anchor (not a toggle bolt), but will the plastic hold up to
> one of these?  It's the kind that spreads 4 metal "blades" out as you
> tighten it, and is permanent once installed.  Any help would be greatly
> appreciated.  I could probably use the stock attachment point, but I want
to
> make sure this thing is stout.  My motor of choice is going to be the H165
> Redline.
> Thanks, David
>             NAR # 79313


 
 
 

LOC IV Nose Cone Attachment Q

Post by Davi » Tue, 05 Mar 2002 10:56:42


The stock attachment point is plenty strong enough.  Remember, the
attachment only has to handle the weight of the nose cone, not the entire
rocket.  A plastic nose cone doesn't weigh much and won't have much momentum
from the ejection charge once the shock cord has fully extended.

-- David

Quote:
> I'm building this for my Level 1 attempt, and I'm using tubular nylon and
> quick links for the shock cord.  I'd like to install an eye bolt for
> attachment to the nose.  How do most of you do this?  I've thought of
using
> a hollow wall anchor (not a toggle bolt), but will the plastic hold up to
> one of these?  It's the kind that spreads 4 metal "blades" out as you
> tighten it, and is permanent once installed.  Any help would be greatly
> appreciated.  I could probably use the stock attachment point, but I want
to
> make sure this thing is stout.  My motor of choice is going to be the H165
> Redline.
> Thanks, David
>             NAR # 79313

 
 
 

LOC IV Nose Cone Attachment Q

Post by Jackbear » Tue, 05 Mar 2002 14:08:48


Quote:
>The stock attachment point is plenty strong enough.

I beg to differ. I used a standard 4" LOC nosecone on a scratchbuilt project on
an I211, and with a bit late delay the little plastic loop for attaching the
nose cone did fail. The chute, shock cord, and main airframe stayed connected,
but the nose free fell. And I was using not TN but elastic which puts less
strain on things anchored to it.

To attach to plastic nosecones, I cut two slots one on each side of the center
of the base of the nose, about half way out from center to perimeter. I run the
shock cord through these two slots.
Jack W. Kale, Jr. NAR #70384 Insured, Tripoli #5798 Level 2

Triple the shock cord! Use more epoxy! Always fly straight up- you need the
exercise anyway.

 
 
 

LOC IV Nose Cone Attachment Q

Post by Jim Rutkowsk » Tue, 05 Mar 2002 22:00:46


David,

There is nothing wrong with the LOC method, saves the weight of the
anchor too.

However, if you have your heart set on a hardware anchor, use a U-bolt
in your top CR. It's what the big boys use.

Jim Rutkowski
NAR 78314 L2
Superstition SpaceModeling Society

Quote:
>I'm building this for my Level 1 attempt, and I'm using tubular nylon and
>quick links for the shock cord.  I'd like to install an eye bolt for
>attachment to the nose.  How do most of you do this?  I've thought of using
>a hollow wall anchor (not a toggle bolt), but will the plastic hold up to
>one of these?  It's the kind that spreads 4 metal "blades" out as you
>tighten it, and is permanent once installed.  Any help would be greatly
>appreciated.  I could probably use the stock attachment point, but I want to
>make sure this thing is stout.  My motor of choice is going to be the H165
>Redline.
>Thanks, David
>            NAR # 79313

 
 
 

LOC IV Nose Cone Attachment Q

Post by Jim Rutkowsk » Tue, 05 Mar 2002 22:15:18


David,

OOPS, I miss-read your post, to attach a NC I'd cut-off the end,
scuff-up the inside of the tip with 80grit, wash it with acetone and
epoxy in either a nice stout piece of Kevlar or an eye bolt with some
washers. Or, you could think ahead and epoxy in a length of threaded
rod for a future altimeter mount.

Jim Rutkowski
NAR 78314 L2
Superstition SpaceModeling Society

Quote:
>I'm building this for my Level 1 attempt, and I'm using tubular nylon and
>quick links for the shock cord.  I'd like to install an eye bolt for
>attachment to the nose.  How do most of you do this?  I've thought of using
>a hollow wall anchor (not a toggle bolt), but will the plastic hold up to
>one of these?  It's the kind that spreads 4 metal "blades" out as you
>tighten it, and is permanent once installed.  Any help would be greatly
>appreciated.  I could probably use the stock attachment point, but I want to
>make sure this thing is stout.  My motor of choice is going to be the H165
>Redline.
>Thanks, David
>            NAR # 79313

 
 
 

LOC IV Nose Cone Attachment Q

Post by Davi » Tue, 05 Mar 2002 21:16:09


I would have to guess that for every possible failure, there is one reader
of RMR who has had it happen.  SO, to prevent that, I recommend that you
replace every component in your rocket kit with an exact duplicate made of
carbon fiber re-inforced with kevlar and two wraps of fiberglass.

You've got to pick your battles, guys.  With an unweighted plastic nosecone,
the stock mount should be strong enough. If it breaks, you are probably
using too short a shock cord.  I must admit, though, that cutting two slots
and passing the shock cord through is a simple solution that might be worth
the extra insurance.

You could try a ground test.  lay the NC on the grass, attached to the shock
cord.  Yank the other end of the cord as hard as you can.  If it survives
that, it will survive the launch (unless you are using too short a shock
cord).

-- David

PS - this is my 2 cents.  Everyone is free to choose the degree to which
they want to overbuild their rocket.


Quote:
> >The stock attachment point is plenty strong enough.

> I beg to differ. I used a standard 4" LOC nosecone on a scratchbuilt
project on
> an I211, and with a bit late delay the little plastic loop for attaching
the
> nose cone did fail. The chute, shock cord, and main airframe stayed
connected,
> but the nose free fell. And I was using not TN but elastic which puts less
> strain on things anchored to it.

> To attach to plastic nosecones, I cut two slots one on each side of the
center
> of the base of the nose, about half way out from center to perimeter. I
run the
> shock cord through these two slots.
> Jack W. Kale, Jr. NAR #70384 Insured, Tripoli #5798 Level 2

> Triple the shock cord! Use more epoxy! Always fly straight up- you need
the
> exercise anyway.

 
 
 

LOC IV Nose Cone Attachment Q

Post by Kurt Kesle » Tue, 05 Mar 2002 23:03:30




Quote:
> I would have to guess that for every possible failure, there is one reader
> of RMR who has had it happen.  SO, to prevent that, I recommend that you
> replace every component in your rocket kit with an exact duplicate made of
> carbon fiber re-inforced with kevlar and two wraps of fiberglass.

> You've got to pick your battles, guys.  With an unweighted plastic nosecone,
> the stock mount should be strong enough. If it breaks, you are probably
> using too short a shock cord.  I must admit, though, that cutting two slots
> and passing the shock cord through is a simple solution that might be worth
> the extra insurance.

I am going to agree with Jack.  Those loops do break occasionally and it
is trivial to cut some slots or add an eye bolt to prevent that
particular failure.

--
Kurt Kesler

 
 
 

LOC IV Nose Cone Attachment Q

Post by Barry Lync » Wed, 06 Mar 2002 00:25:16


If you are going to add weight to any of our rockets (i.e. fiberglass,
electronics, reinforcements and nose weights) please do not use the eyelet
attachment, this is only designed to withstand pressures just beyond the
fail point of the elastic provided.   Although you may be successful on many
flights with this connection, it is best to modify your nosecone to
accommodate the extra stress (F=MA) that it will see as a result of this
mass increase.

My preferred method is cutting 2 slots approximately half way from the
center of the cone to the shoulder and running a strap of the material you
are using for the "shock cord" (harness) through these 2 holes and tying
them together.  This spreads the force over the strongest part of the cone
and has worked for me for years.  In addition, the weight added is far less
than incorporating eyebolts, plates and other hardware.

Please fly safely and promote our hobby EVERYWHERE!   We need to triple the
number of flyers this year to help drive the costs down for everyone!

Barry ***
LOC Precision
Fly Safe, Fly Hard, Fly LOC!


Quote:
> I'm building this for my Level 1 attempt, and I'm using tubular nylon and
> quick links for the shock cord.  I'd like to install an eye bolt for
> attachment to the nose.  How do most of you do this?  I've thought of
using
> a hollow wall anchor (not a toggle bolt), but will the plastic hold up to
> one of these?  It's the kind that spreads 4 metal "blades" out as you
> tighten it, and is permanent once installed.  Any help would be greatly
> appreciated.  I could probably use the stock attachment point, but I want
to
> make sure this thing is stout.  My motor of choice is going to be the H165
> Redline.
> Thanks, David
>             NAR # 79313

 
 
 

LOC IV Nose Cone Attachment Q

Post by Jerry Irvin » Wed, 06 Mar 2002 00:52:58




Quote:
> Please fly safely and promote our hobby EVERYWHERE!   We need to triple the
> number of flyers this year to help drive the costs down for everyone!

I can't remember the last time someone on rmr suggested this.  Almost no
effort is being done in this regard by national or local clubs.  
Existing rocketeers are being serviced but not much outreach is
happening.

Jerry

Quote:
> Barry ***
> LOC Precision
> Fly Safe, Fly Hard, Fly LOC!

--
Jerry Irvine, Box 1242, Claremont, California 91711 USA

Please bring common sense back to rocketry administration.
 
 
 

LOC IV Nose Cone Attachment Q

Post by Mark Simpso » Wed, 06 Mar 2002 08:29:24


David,
There are lots of ways of improving the stock mount.  The wall anchor
that you mentioned would work as would the type with spring-loaded wings
that pop out after you insert them.  My preferrance is to use an eyebolt
with a large washer and wingnut.  I cut a smile out of the shoulder so
that I can get a finger inside to attach the washer and wingnut.  It
also serves as a means of increasing the noseweight through the use of a
stack of fender washers.

Mark Simpson
NARR 71503 Level II

Quote:

> I'm building this for my Level 1 attempt, and I'm using tubular nylon and
> quick links for the shock cord.  I'd like to install an eye bolt for
> attachment to the nose.  How do most of you do this?  I've thought of using
> a hollow wall anchor (not a toggle bolt), but will the plastic hold up to
> one of these?  It's the kind that spreads 4 metal "blades" out as you
> tighten it, and is permanent once installed.  Any help would be greatly
> appreciated.  I could probably use the stock attachment point, but I want to
> make sure this thing is stout.  My motor of choice is going to be the H165
> Redline.
> Thanks, David
>             NAR # 79313

 
 
 

LOC IV Nose Cone Attachment Q

Post by Mark Simpso » Wed, 06 Mar 2002 08:32:06


Barry doesn't count; he's a vendor. ;-)

Mark Simpson
NAR 71503 Level II

Quote:



>> We need to triple the number of flyers this year to help drive the costs down for everyone!
> I can't remember the last time someone on rmr suggested this.  Almost no
> effort is being done in this regard by national or local clubs.
> Existing rocketeers are being serviced but not much outreach is
> happening.

 
 
 

LOC IV Nose Cone Attachment Q

Post by Davi » Wed, 06 Mar 2002 09:31:09


Just curious, is it stronger to cut the slots in the part of the NC with the
seam, or the part without?

-- David

Quote:
> If you are going to add weight to any of our rockets (i.e. fiberglass,
> electronics, reinforcements and nose weights) please do not use the eyelet
> attachment, this is only designed to withstand pressures just beyond the
> fail point of the elastic provided.   Although you may be successful on
many
> flights with this connection, it is best to modify your nosecone to
> accommodate the extra stress (F=MA) that it will see as a result of this
> mass increase.

> My preferred method is cutting 2 slots approximately half way from the
> center of the cone to the shoulder and running a strap of the material you
> are using for the "shock cord" (harness) through these 2 holes and tying
> them together.  This spreads the force over the strongest part of the cone
> and has worked for me for years.  In addition, the weight added is far
less
> than incorporating eyebolts, plates and other hardware.

> Please fly safely and promote our hobby EVERYWHERE!   We need to triple
the
> number of flyers this year to help drive the costs down for everyone!

> Barry ***
> LOC Precision
> Fly Safe, Fly Hard, Fly LOC!



> > I'm building this for my Level 1 attempt, and I'm using tubular nylon
and
> > quick links for the shock cord.  I'd like to install an eye bolt for
> > attachment to the nose.  How do most of you do this?  I've thought of
> using
> > a hollow wall anchor (not a toggle bolt), but will the plastic hold up
to
> > one of these?  It's the kind that spreads 4 metal "blades" out as you
> > tighten it, and is permanent once installed.  Any help would be greatly
> > appreciated.  I could probably use the stock attachment point, but I
want
> to
> > make sure this thing is stout.  My motor of choice is going to be the
H165
> > Redline.
> > Thanks, David
> >             NAR # 79313

 
 
 

LOC IV Nose Cone Attachment Q

Post by Jackbear » Wed, 06 Mar 2002 10:44:56


Quote:
>> You've got to pick your battles, guys.  With an unweighted plastic
>nosecone,
>> the stock mount should be strong enough. If it breaks, you are probably
>> using too short a shock cord.

When I had my failure I was using twenty feet of elastic. In a five pound
rocket loaded weight.
Jack W. Kale, Jr. NAR #70384 Insured, Tripoli #5798 Level 2

Triple the shock cord! Use more epoxy! Always fly straight up- you need the
exercise anyway.