My questions to Fred in post #45 are still open. But everyone that reads this thread can come to their own conclusions. But I agree, time to move along...
I guess I can't read but the only question I see is "why put your rocket upwind" which I didn't think was really a question.
My response is I like to put the rocket on the front of the pad facing launch control and the spectators....period.
If that's upwind, downwind or sideways I don't care.
I want to see and photograph the rocket taking off.
Your rocket should be strong enough to sit there in any wind and not excessively torque the railbuttons.
If you need to sit out a strong gust and wait for sub-20MPH winds then it needs to survive.
Is that a sufficient answer????
We put our rockets on the LCO side of the rail also. That way the rocket points away from people when we put it up or take it down. And the rail doesn't obscure the rocket.
If I felt my buttons could not hold my rocket in reasonable winds I would install larger buttons and use a larger rail and pad.
If that's upwind, downwind or sideways I don't care.
I just want to be clear as some of you seem to have misinterpreted this issue. This discussion had NOTHING to do with whether or not the buttons are strong enough to hold the rocket on the rail during launch. It is about the location of rail buttons and how they affect the launch.We put our rockets on the LCO side of the rail also. That way the rocket points away from people when we put it up or take it down. And the rail doesn't obscure the rocket.
If I felt my buttons could not hold my rocket in reasonable winds I would install larger buttons and use a larger rail and pad.
The forward rail button goes just above of the forward centering ring and the bottom rail button goes just aft of the aft centering ring.
What's the scientific reason you ask?
When I build a rocket, I get so excited about finishing and installing the motor mount, that I ALWAYS forget to think about rail button placement before hand. Hence, the rail buttons always end up just outside of all motor mount centering rings by default. I have a process!! :wink:
DOOZY of a mistake...
Shorten the coupler a bit....
Your explanation leads me to a slightly different conclusion: The forward guide should be placed far enough forward to support the rocket on the rail in a safe orientation. This does not necessarily mean CG/CP90, and is likely aft of that point. Moving the forward guide any further forward than necessary merely causes it to leave the rail sooner and expose the rocket for an increased amount of time to pitching/yawing moments from the forces you cite while only one guide is in the rail.
Lawdy...we sure know how to over think things don't we?
Lawdy...we sure know how to over think things don't we?
What would the hobby be without overthinking?
The rear guide should theoretically be at CP90 to minimize any turning while the rocket is connected to the rail by only one button, the front should theoretically be as far forward as necessary to prevent the rocket from being able to jostle around too much but as far back as possible to minimize the time spent supported by one button.
Enter your email address to join: