LP Shock Cord Attachment

Does anyone remember seeing an attachment method with the flat elastic ribbon going up and down through slits in a paper and the whole thing then glued in? (In the figure, the mustard color is the tube wall, the red is the paper, and the black is the elastic.) Was it maybe Centuri's answer to the trifold?

I'm planning something similar for an E to H bird (I'll post more on that when I have pictures) and it seems really familiar.

(Not to scale. Duh!)

Could it be the Enerjet (Centuri) shock cord attachment?
https://www.forums.rocketshoppe.com/showthread.php?t=18261&page=1&pp=10
Looks like an upscale of the Stine shock cord mount.

I do this on some models. I use about 3 inches of stiff paper, like cardstock. Make 4 slits in it starting them about 1/2 an inch from one end and 1/2 an inch apart. Tie a knot in one end of the shock cord and thread the other end through the slits so that the knotted end is underneath the paper when done. Apply glue and slap it in.

I found an archived post on Chris' blog showing both the Centuri and Stine shock cord mounts:
https://modelrocketbuilding.blogspot.com/2010/09/mpc-martian-patrol-build-part-8-shock.html
Sure beats cutting two slits in the tube and threading the shock cord in and tying a knot.
Cave man days.

These all look like variations on the Teabag theme to me. Different ? Certainly. Better ? IDK

Looks like it was the Centuri that was making this ring a bell. No surprise, since I spent time looking at Centuri catalogs back when. (Never build any, or my memory would probably be clearer.)

kuririn said:

I found an archived post on Chris' blog showing both the Centuri and Stine shock cord mounts:
https://modelrocketbuilding.blogspot.com/2010/09/mpc-martian-patrol-build-part-8-shock.html

Click to expand...

You beat me to it BarGeezer!
Here's a good picture of the MPC Stine "Shock Lock" mount - Note the shock cord on some smaller MPC kits was a heavy string.
This style mount was a littler flatter than the Estes Tri-Fold mount. On the low 2/3 of the mount, you could place the string overlap side by side, not "stacked".

Oh, heck, why wait. Here's the plan.

When I caught building go fever for my LOC Park Flyer Magnum, I forgot to attach the elastic ribbon to the forward centering ring as directed. (Yes, I'd read the directions when I first opened the package, and then didn't re-read them when I started building.) At first my recovery plan was to make a duplicate forward ring, cut the tube, install the new ring and elastic, then put it back together with a coupler. Not a desirable process.

So I decided to use something like the above, configured like this:

This time the red is cotton cloth. The grey that the ribbon goes around is a stiff wire, cut from a middle weight paper clip, and curved to match the tube's ID. Notice how the "outgoing" end of the ribbon is captive between the cloth and the "incoming" part. Once it's assembled and the slack pulled out (or perhaps during assembly) it all gets saturated with BSI 30 minute epoxy, inserted into the tube which is also wetted with epoxy, and balloon clamped. (I'll have to round and smooth the cut ends of the wire so they don't pop the balloon.)

That sounds like fun. Please take pics as you go!

I had a whole quiet weekend to myself, and hardly did anything, rocket related or otherwise. But I did make the wire for this shock cord mount. Hammered a piece of paper clip, first straight then on a piece of pipe to make a circular arc. It has to be a smaller pipe than the intended final size because of the way the wire springs back. Checking it against the nose cone shoulder along the way, because that's easier than checking against the inside of the tube. It introduces a small error that I think will not wind up important. Then I sawed off the length I want to use, and filed the ends smooth and round so they won't pop the balloon.

Joe, here's an alternate shock cord attachment method from LOC you may want to consider. Should be fine for a Park Flyer. Very simple, just a length of braided nylon cord, masking tape and epoxy. See step 4.
https://locprecision.com/wp-content/uploads/PK12-Onyx-Instructions.pdf

That does look fine. I'm keen to try the method I dreamed up, which I'm confident will also do fine.

I got it installed yesterday. It went together fine, but going into the tube wasn't so clean. I should have known better; there's jut not much space to work inside a thick wall BT-60. So it got crumpled up while being pushed down with a dowel. And I should have bought the long skinny balloons; I couldn't get on in place. So it's not pretty, but I feel OK about it all the same.