Crushing Sleeve

Discussions about rockets, construction materials, adhesives, nozzles, nosecones and fin design.
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Alien Space Agency
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Crushing Sleeve

Post by Alien Space Agency »

Good Morning guys! (I posted this on a sunny 11am morning)

So as Bruce Berggren recommended to use a rubber tube as a sheath for the stager on his site, has anyone made a sheath other than a rubber tubing?

So far I have experimented with heatshrink tubing... at first it sounds funny, but yes, I did make one.

With less elasticity, the sleeve will release the nozzle even at a lower pressure, unlike most rubber tube CS stagers requiring 30-40 psi minimum pressure. Heatshrink CS stagers will separate even at 15 psi.

But with less elasticity, another problem arises. The heatshrink cannot handle sudden pressure changes.

Here's how it looks like:
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Untitled.png (20.74 KiB) Viewed 44 times
Alien Space Agency Flight Report April 1, 2016

2-stage Flight #1 (80 psi)

First Stage: Good Boost, clean separation
Second Stage: Nice long spiraling sustain (due to overly misaligned nozzle and the fact that the rocket is spin-stabilized)

2-stage Flight #2

First Stage: Good boost, stager failed to separate stages (sleeve burst)
Second Stage: Continued to climb about 50 feet with the heavy booster on its back. Water column traveled through booster nozzle.
Result? :stars:

So the rebuild of the stager will use the larger 10mm HS tubing shrunk to 7mm ID (shrunk over pen tube) plus two other layers, and a reinforcing tape (just regular Scotch tape) near the valve (greatest force on staging)

Kudos
Maru Razz: Razz: Razz: Razz:
Nothing can stop a curious mind from inventing- Anonymous