how to attach shock cord to nose cone?

[bjphoenix]

I'm re-using a old BT60 nose cone that has most of the base cut off including the molded in loop for the shock cord, it's just part of the shoulder left and a hollow base. I'm wondering how to connect a shock cord. The only thing I've come up with is to make a disk to glue in as a bulkhead right in front of the shoulder and connect a loop of wire or kevlar to that. I did this for my Big Daddy to eliminate the suspicious angle at one side of the original nose cone shoulder.

 

[mh9162013]

I think your suggestion is as good as any. But while you're at it, you could consider having a nose-cone payload bay using a bottle cap or screw-on engine retainer.

 

[MarsLander]

The only thing I've come up with is to make a disk to glue in as a bulkhead right in front of the shoulder and connect a loop of wire or kevlar to that.

Yep.

 

[David Schwantz]

I've done that quite often. You can drill 2 holes and loop a kevlar piece through it. I have also pushed a u shaped piece of music wire through the 2 holes and then bent little feet on the backside to prevent pull through.

 

[bjphoenix]

I've done that quite often. You can drill 2 holes and loop a kevlar piece through it. I have also pushed a u shaped piece of music wire through the 2 holes and then bent little feet on the backside to prevent pull through.

I just have shoulder, none of the bulkhead behind that. I was originally thinking this wouldn't work but I need to check clearance between the shoulder and the ID of the body tube, there might be room for a couple of pieces of thin wire.

 

[David Schwantz]

Shoulder is all you need. Make a bulkhead of the correct size, round, one that just barely fits into NC. Squeeze the NC so you can install bulkhead past shoulder, flip it around, flat, and glue in place. Don't forget to rough up plastic for gluing.

 

[Titan II]

Just epoxy a length of Kevlar to the inside of the cone. You then attach the shock cord to that. Same concept as attaching a shock cord to a motor mount. Simple, strong, light, and takes up negligible space. Rough up plastic as David mentioned above.

 

[SolarYellow]

If you're going to use ballast, put an eye screw through a little disc of wood to act as a "float." Make a short, heavy-duty Kevlar leader with a loop through the eye screw and another loop on a long enough length of line to extend past the bottom of the shoulder, so you can tie stuff to it. Use whatever ballast media you want, epoxied in the tip of the nose cone, with some rods put through holes across the tip to lock it all in. Once the epoxy and ballast are in there, set the eye screw and float with kevlar leader attached on the epoxy, so the threads of the screw stick down into the media. Might be good to smear the threads and bottom of the float with epoxy. Keep the kevlar out of the epoxy. It will be a solid anchor for any LPR when it cures. And it leaves almost the full volume of the NC available for laundry.

 

[Back_at_it]

Do a bulkhead that sits above the shoulder inside the nosecone then connect a screw eye to that for the shock cord.

 

[bjphoenix]

Do a bulkhead that sits above the shoulder inside the nosecone then connect a screw eye to that for the shock cord.

This was mentioned several times and I might do this, I did the same thing for my Big Daddy some years ago. I'm trying to do the lightest solution possible, the idea for this design is something a bit shorter than an ESAM but will fly decently on a B6.

 

[David Schwantz]

If you want light weight, do not use an eye bolt. Just loop kevlar through 2 holes in bulkhead.

 

[SolarYellow]

For lightest possible weight, just epoxy a Kevlar loop to the inside of the cone. I've had good luck with JB Weld Plastic Bonder epoxy. It seems to have some additional solvent in it that helps it bite into the polymer, kind of like a solvent adhesive system.