I have an old Streak I would like to build. I want to make it as light as possible so I am going to hollow out the nose cone and use the competition fin design as called out in the plans.

Instead of using the body wrap, would it be possible to glue the fins and nose cone directly to the clear tube using a "modern" glue?

In addition to the weight reduction aspect, I think it would be cool to leave the tube clear.

Thanks....

This is an actual Streak kit? If so, the tube is mylar. I can't recommend a glue, but you might consider cutting narrow strips of the adhesive backed paper just wide enough to glue the fins to. Go easy on the glue fillets. If it shrinks, it will lift the paper.

[Edit: These rockets can be flown on B and C motors. They are notorious for being lost on these kinds of motors. Making one into an extra high performance rocket only increases the chances of losing it. YMMV.]

Doug

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YORF member #11

If you really want to lose it use a D10
Mr. Bob
Starlight Model Rockets LLC
www.starlightrocketry.com

I suspect that the idea of trimming the gummed paper bonding surfaces down to narrow strips may not work too well. In the Streak, the adhesion of the fins is only as good as the bond of the gummed paper to the tube, since the fins are glued to the paper, not to the tube. And I think that in order for the paper to perform its role, it has to have an appreciable area of contact with the tube. Basically that means that it needs to wrap completely around the tube. The method that Estes uses to adhere the fins actually seems to me to be a quite lightweight and low-drag approach. Alternatives such as direct bonding with epoxy or polyurethane glue would require much more adhesive and larger fillets, I would think, and would have a more significant negative impact on performance.

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SAM # 0011

I don't know how hot the outside of the D10 gets, but I would think that the combination of higher impulse and a longer burn time would result in a melted tube. The Streak looks like it needs relatively short-burn motors that don't get too hot.

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SAM # 0011

I'm not sure but wasn't the Streak BT equivalent to a BT30? If so, the following may help.....

1. Mark the BT for fin placement.
2. Drill small diameter holes on line.
3. Apply a heavy coating of wax to an expended 18mm motor (or engine as preferred).
4. Insert waxed motor (engine) into BT. You may need to tape the end to ensure the motor stays in place.
5. Apply a line of epoxy (the type that dried clear) to the root edge of the fin.
6. Place fin on placement line ensuring epoxy is forced into holes drilled in the BT.
7. Once all fins are set and the epoxy has cured, remove the motor (engine)

This method should result in "rivets" inside the body tube to aid in securing the fins to the BT. The wax coating on the motor (engine) should prevent the epoxy from adhearing to the motor (engine). You can also use the clear epoxy to make fillets. Use it sparingly. A finger soaked in alcohol can be used to help form the fillet (some folks would recommend latex gloves instead of the bare finger to avoid a possible future chemical alergy to the epoxy).

Of course, if the BT is indeed equivalent to a BT20, then just disregard everything above or use 13mm motors with an adapter.

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Don
NAR 53455
"Carpe Diem"

BT 10: ID = 0.710"; OD = 0.720"

Much, much thinner walled and smaller in diameter than BT 30. Same inner diameter as BT 20, but with dramatically thinner walls.

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SAM # 0011

Mark,

Scott's not gonna get it back anyway, so how will he know if the fins came off?

You're probably right that a mere strip will come unglued. The heat of the motor will surely soften the grab, so for a few moments at least, the fins will be much more susceptible to separation.

OTOH, I'm not really sure what other glues would be good with mylar. I'm thinking maybe medium or thick CA. That will need to be held in place for a while until the glues hardens, but so does Elmer's, so that won't be an undue burden.

Doug

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YORF member #11

[Edit: These rockets can be flown on B and C motors. They are notorious for being lost on these kinds of motors. Making one into an extra high performance rocket only increases the chances of losing it. YMMV.]

LOL...You'll put your eye out

I think I am going to try a CA using the drill/rivet method described above.

Thanks!

At the risk of getting on Don's bad side ... Do a test first to be sure the CA won't stick to the waxed motor. The other concern I have with this is how snugly the motor fits inside the tube. If it's a little loose, the CA could spread around quite a bit and cloud the tube on the inside.

Doug

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YORF member #11