Shock cord attachment technique

Hello All
I am in the process of adding a payload section to a couple of my 3.9" dia. rockets.
I decided to go with a 3" dia. payload bay just to give the rockets a little different look.
The problem I have is with the shock cord attachment point on the 3.9" to 3.0" reducer I have.
It is small dia. plastic under 1/8" and I do not trust it.
It does not make much sense to attach a 5/8" nylon shock cord with a 3/16" quick link to a 1/8" dia. piece of plastic.
I would like to attach the shock cord to an eye bolt as I do on nose cones.
The problem here is the plastic on the bottom of the reducer is to thin to drill and tap for an eye bolt.
Suggestions anyone.
Thanks much
L.T.

Can you cut a hole in the side of the transition (the part that couples into the tube) thus gaining access for a nut/washer combination on the inside? Then you could use a regular threaded eyebolt, securing it with a nut/washer. You'd have to drill a large enough hole to accommodate your favorite flavor of eyebolt.

Another option would be to remove the end entirely (leaving the coupler portion, and glue a bulkhead of light-ply into the interior, with eyebolt secured to it. Again, use a nut/washer combination on the back to hold the eyebolt.

That help?

N

The hole in the side approach is what I was plannnig on using.
Thanks much.

How about going all the way through the transition? I've found 6" I bolts at HomeDepot. You could just add (glue) a piece of light ply to the bottom over the plastic to spread any load and do the same for the top. Quick and easy....
v/r
Jerry

Does this transition need to be hollow or can it be "solid"? If it can be solid then use 2 part expanding foam as well to add some Grab and structure to the part.

Cut a circle in the bottom end of the Transition along the outermost mark, about 1/8" inside the edge. Now, you have a 3.9" shoulder with (let's say) a 3.8" lip.

Then, take a 1/8" wood bulkplate with a U-bolt properly mounted and trim it with a Dremel tool till it is the same size as the inner diameter of the transition, but bigger than the hole you just cut (3.85" for example).

Now, flatten the bulkplate on two sides, so that you can turn it on its side and slide it inside the edge of the lip, but the rounded edges still catch on the lip when you pull it down.

Pull it down into place and epoxy it there. You have to roughen the inside surface of the plastic to get the epoxy to adhere to it. This could be a slight problem, but play with it...

There's always the BFI (brute force and ingnorance) method. Install a bulkhead above the transistion and put a long eyebolt through the bulkhead and transition. Then there won't be many of those worrisome engineering issues.

John