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Delay Questions

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gna

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Generally speaking, is it better for a motor delay to be too long or too short? I've been using Open Rocket to sim some rockets with a variety of motors. Often times OR will call for an optimum delay that is "in between" what my choices are. For instance, I simmed a rocket with an Aerotech E15W. The optimum delay is 5.4 seconds, but my choices are 4 seconds and 7 seconds. So would I better off with the 4 second delay, or the 7 second delay?
 

rharshberger

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Both will work but I would go with the 7, + or - 1 second is best, but 1.6 seconds long should be okay too.
 

SaturnV

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Too long:
[video=youtube;F1xA6OiFriE]https://www.youtube.com/watch?v=F1xA6OiFriE[/video]
[video=youtube;3vgp6wqhsYM]https://www.youtube.com/watch?v=3vgp6wqhsYM[/video]
Too short:
[video=youtube;YR-nFtVfIdc]https://www.youtube.com/watch?v=YR-nFtVfIdc[/video]
[video=youtube;5UmGROGNeE0]https://www.youtube.com/watch?v=5UmGROGNeE0[/video]
In general, the parachute opens at high speed.In weaker structures - the destruction of the rocket.
Especially HPR with short charge broke parachute as stem of the flower and fly without a parachute :)
P.S.
In this case it is obtained practically other reasons for short or long charge in these flights are quite different. Related to the engine or its ignition or particulary destruction or etc. :)But in practice we have short or long delay of what you ask :)
 
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SaturnV

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Very specifically to your question. If your rocket is strong enough in a short delay will not reach maximum altitude and at long will land faster. But this only in case that the structure of the rocket and parachute withstand impact when opening chute:)
 
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