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Old 12-21-2013, 01:29 AM
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astronot astronot is offline
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Quote:
Originally Posted by Rex R
the stated delay times are measured from motor (propellant) burn out, just like the Estes motors you're used to. yes the delay starts burning at motor ignition But, that has been allowed for by the motor maker, all you have to worry about is the coast time.
yes the F24 has a lower thrust but it has a longer burn (as denoted by the difference in total Newtons 50 vs 40) the Estes E9 has a lower thrust than the D12. running flight simulations in 'Open Rocket' helps a lot in finding the 'right' motor. The hand book of model rocketry has a nice chapter on rocket motors and what all those numbers mean.
Rex


OK. That clears it up some. They are treating these 24mm motors similar to BP motors of the same size, that why the burn times are not listed. I wish they were though. Is they some place I can find out this info before I buy? Sometimes I want a nice slow burn and then sometimes I don't.

But am I correct in assuming that this is not the case for stated delay times for motors of 29mm and higher. Should I take into account the total burn time of the motor and subtract that from the delay time to find out what my actual coast time will be?

Thanks for addressing this for me.

David
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