multiple splice vs. tornado coupling

[Strattocoaster]

Why do folks choose to use tornado couplings vs multiple splices to make one long unobstructed tube?

[WRA2]

Why do folks choose to use tornado couplings vs multiple splices to make one long unobstructed tube?

There are several reasons to use them despite the performance loss caused by the extra weight and small opening.

1. building a "modular rocket" (this allows the rocket to be disassembled for transportation, and also sections can be removed and replaced easily should there be a failure or crash damage)
2. The joints provide attachment points for boosters, fins and deployment systems etc.
3. The joints keep the rocket centered on the launch tube.
4. rocket volume can be adjusted to meet weather or launch site restrictions simply by removing a section.

[Strattocoaster]

Makes perfect sense. Thanks for the quick response.

[U.S. Water Rockets1]

Why do folks choose to use tornado couplings vs multiple splices to make one long unobstructed tube?

Tornado couplings really reduce the volume inside the rocket, so you will always suffer a weight and thrust penalty when you use them. It is always best to try and keep the number of tornado couplings to a minimum, unless you have a compelling need to use them. If you are not able to make strong spliced joints, you may want to use multiple segments, because you can build and test many segments and then keep the ones that don't fail and couple them with tornado tubes.

[Nick B]

Why do folks choose to use tornado couplings vs multiple splices to make one long unobstructed tube?

Tornado couplings really reduce the volume inside the rocket, so you will always suffer a weight and thrust penalty when you use them. It is always best to try and keep the number of tornado couplings to a minimum, unless you have a compelling need to use them. If you are not able to make strong spliced joints, you may want to use multiple segments, because you can build and test many segments and then keep the ones that don't fail and couple them with tornado tubes.

This x 100.

Also, if you intend to compete within WRA rules, A leaking rocket will not comply.

If you intend to use sub 120 psi pressures, avoiding robinson, and tornado couplings is a solid gain in weight savings and thrust impulse.

[WRA2]

Also, if you intend to compete within WRA rules, A leaking rocket will not comply.

Nick,

Where in the rules does it say that the rocket cannot leak . If you were complying with the safety rules and there are no metal parts on your pressure vessel and you are 50 feet away from it when it is pressurized, who cares if it leaks. If it blows up, you have to rebuild it. Leaks would only affect performance of the rocket (losing reaction mass or pressure).

There is nothing in the rules about leaks.

[Nick B]

"To prevent "stomp rockets" competitors using bottled air must leave the rocket at full launch pressure for a period of no less then ten (10) minutes prior to launching. (The ground view camera will show both the tank and rocket on the launcher during this 10 minute period)."

http://www.wra2.org/WRA2_Class_A_Rules.php



irrelevant to me.....btw......

[WRA2]

"To prevent "stomp rockets" competitors using bottled air must leave the rocket at full launch pressure for a period of no less then ten (10) minutes prior to launching. (The ground view camera will show both the tank and rocket on the launcher during this 10 minute period)."

http://www.wra2.org/WRA2_Class_A_Rules.php



irrelevant to me.....btw......

That just means you have to maintain pressure. A leaking rocket could be continually refilled to hold the pressure or the team could use a compressor which fills the rocket slowly (leaks would also make it so that it takes longer to fill with the compressor). Since a leaking rocket would be more of a performance issue it would be in the teams best interest to build a rocket that does not leak but it isn't forbidden by the rules.