Hi everyone,
This thread caught my attention. I have been considering trying dual deployment, but I did not want to conflate that process with building a new high-powered rocket. I already have a nice, frequently flown Estes Firestorm, which as you know is an almost ready-to-fly low-powered rocket. So I have now started investigating DD using my Firestorm.
I went to the Apogee Components website, where I read and listened to Tim's highly instructive material. I learned a lot.
To begin with, here is what I think I understand:
You construct an avionics bay containing two ejection charges. The forward charge will cause the forward air tube containing the large, main parachute to separate. The aft ejection charge acts on the aft air tube containing the small drogue parachute. Actually, for small rockets, Tim suggested not to use a drogue at all -- and instead just to let the rocket drop until the main parachute slows the descent.
But here is what I don't understand:
Why do you need an aft ejection charge? Won't the ejection charge of the rocket motor cause the aft air tube to separate?
Thank you.
Stanley