Attaching nosecone to payload section

Attaching nosecone to payload section

Post by Jim » Thu, 23 Apr 1998 04:00:00




Quote:

> 3) Bolts.  Figure out some way to get a nut behind the hole in the
> nosecone, and use bolts.  How would I get the nut in?

Duct tape on the end of a stick has worked for me for some applications
(I assume the problem is getting the nut through a little hole and holding
it in place while you tighten the bolt).

But why not just a sheet metal screw? It will just be loaded in shear so you don't
really need a nut on the inside.

Or, drill and tap the body tube (Phenolic, right?) to take a screw.

How thick is the body tube/nose? Drill and tap for a set***- that will make
everything flush - use a little loc-tite (sp?) to keep it from coming loose.

--
Jim K.        ! Opinions: You want? I got!

 
 
 

Attaching nosecone to payload section

Post by Alan W. Holm » Fri, 24 Apr 1998 04:00:00


I've just about completed building a payload section for my PML
Tethys.  Just about the only thing left is to decide how the nose cone
will attach to it.  I've thought of 3 ways to do this, but don't know
what method others have found best.

1) Friction fit by putting tape on the nosecone shoulder.  Problem:
I'm not much of a fan of (or very good at) friction fitting.  This
method sounds most likely to lose the nosecone and payload.

2) PML pop-rivets.  I've never actually used these for anything, but
I've seen others use them in the orginal CPR model.  I think (but am
not certain) that they'd be long enough to go through the body tube,
the small space, and the nosecone shoulder.  I'm leaning toward using
this approach.

3) Bolts.  Figure out some way to get a nut behind the hole in the
nosecone, and use bolts.  How would I get the nut in?

Comments and suggestions welcomed!

Alan Holmes


 
 
 

Attaching nosecone to payload section

Post by Jim Yan » Fri, 24 Apr 1998 04:00:00



Quote:

>I've just about completed building a payload section for my PML
>Tethys.  Just about the only thing left is to decide how the nose cone
>will attach to it.  I've thought of 3 ways to do this, but don't know
>what method others have found best.

>1) Friction fit by putting tape on the nosecone shoulder.  Problem:
>I'm not much of a fan of (or very good at) friction fitting.  This
>method sounds most likely to lose the nosecone and payload.

>2) PML pop-rivets.  I've never actually used these for anything, but
>I've seen others use them in the orginal CPR model.  I think (but am
>not certain) that they'd be long enough to go through the body tube,
>the small space, and the nosecone shoulder.  I'm leaning toward using
>this approach.

>3) Bolts.  Figure out some way to get a nut behind the hole in the
>nosecone, and use bolts.  How would I get the nut in?

>Comments and suggestions welcomed!

>Alan Holmes


If you are looking for a permanent attachment,you could try the new
polyurethane glues like PROBOND(Elmer's,I think). I have glued plastics with
this stuff,and the bond is very good.It works very well on metals,too. It does
'foam up' to fill any gaps,and would have to be sanded or trimmed.
As far as nuts,you could use 'pressnuts',which are intended for pressing into a
metal panel,and filletting glue around them for retension.

Jim Yanik,NRA member.

 
 
 

Attaching nosecone to payload section

Post by dave_theden » Fri, 24 Apr 1998 04:00:00


Quote:

> I've just about completed building a payload section for my PML
> Tethys.  Just about the only thing left is to decide how the nose cone
> will attach to it.  I've thought of 3 ways to do this, but don't know
> what method others have found best.

Sounds like the payload section is already built, but I would put an eye
bolt in the bulkhead so that I could run a small length thin tubular
nylon from the eye bult to the nose cone.  You can never lose it that
way.  But keeping it on at ejection is just a mater of enough tape.  But
I like the idea of the PML snap rivets or a couple of smal screws.  I
usualy use the payload section for main chute deployment so friction fit
is all I use.

Quote:
> Comments and suggestions welcomed!

> Alan Holmes


dave
--
TRA #5145      NAR  #69923      LEUP
Level 2        Level 0
 
 
 

Attaching nosecone to payload section

Post by Bob Kapl » Fri, 24 Apr 1998 04:00:00



Quote:
> I've just about completed building a payload section for my PML
> Tethys.  Just about the only thing left is to decide how the nose cone
> will attach to it.  I've thought of 3 ways to do this, but don't know
> what method others have found best.

I've used #2 sheet metal screws. I got a hundred of them for a buck from
American Science and Surplus a few years back, but they are also available
from Micro Fasteners. The only time they ever failed is when my camera
carrier tore up when the I161 ejected a second after burnout, and trashed
most of the rocket. Figure one***for inch of body diameter as a place to
start. I space them evenly around the tube, along the center line of the
shoulder.

        Bob Kaplow      NAR # 18L       TRA # "Abort, Retry, Fail?"

Kaplow Klips:   http://www.FoundCollection.com/
NIRA:           http://www.FoundCollection.com/

 
 
 

Attaching nosecone to payload section

Post by Dale Eme » Fri, 24 Apr 1998 04:00:00


Quote:

>2) PML pop-rivets.  I've never actually used these for anything, but
>I've seen others use them in the orginal CPR model.  I think (but am
>not certain) that they'd be long enough to go through the body tube,
>the small space, and the nosecone shoulder.  I'm leaning toward using
>this approach.

I use the PML pop-rivets to hold the nose cone on my Shadow and my LOC
HiTech and Viper III.  They work great, and they are quicker than sheet
metal screws I have used before.  And you don't have to take a screwdriver
with you. I put three of the around, line them up with the fins.

Dale Emery
NAR #70702, TRA #5786 (L1)

 
 
 

Attaching nosecone to payload section

Post by Jim Clear » Sat, 25 Apr 1998 04:00:00


Quote:

> I've just about completed building a payload section for my PML
> Tethys.  Just about the only thing left is to decide how the nose cone
> will attach to it.  I've thought of 3 ways to do this, but don't know
> what method others have found best.

> 1) Friction fit by putting tape on the nosecone shoulder.  Problem:
> I'm not much of a fan of (or very good at) friction fitting.  This
> method sounds most likely to lose the nosecone and payload.
><SNIP>
> Comments and suggestions welcomed!

> Alan Holmes


What about using another "I" bolt in the bottom of the payload section
with a shock cord running to the nose cone? Then friction fit the cone
in place, if the cone comes loose on deployment or landing at least you
wont lose it.
--
Fly Contented if not Happy.
                        Jim C.
                        TRA #3996 Level 2
                        METRA
"Any idiot can face a crisis, it's this day to day living that wears you
out." - Anton Chekhov
"Times fun when your having flies!" - Kermit the Frog
 
 
 

Attaching nosecone to payload section

Post by Ben Brockwel » Thu, 30 Apr 1998 04:00:00


In my mind, there are two approaches to this situation:
1. For a permanent hold, use West System Epoxy. You can pick it up at a
hobby shop or marine store. It WILL HOLD ANYTHING together. I mean
ANYTHING.
or
2. Use the PML plastic rivets. This way, you can get a strong hold ( I use
them on the 9 ft, 6 in diameter Ult. Endeavour and they work great) and at
the same time you can just pop them off to change or add/remove payloads
from the rocket.

Hope this helps,
-Ben
TRA 5870 Cert Lvl. 2