Ejection Charges for D motors

Hey guys, I'm currently making a 24mm cluster fatboy and have added 9 oz to
the nosecone...i know it seems like a lot but it will let me fly on a wide
range of estes D engines and aerotech composite motors..after i added the
weight i weighed the entire nose cone and it turn out to be 9.7 oz. will 3
d12-5 ejection charges be enough to blast this nosecone off the rocket? I'm
thinking of having a 7 ft shock cord...will this be enough...
thanks!
-Vishal
Reply to
Vishal
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I doubt there will be a problem with the ejection. Plus, hopefully the rocket will be arcing over anyway. I've seen something similar though in terms of nose weight on a standard Estes cone and the extra weight made the momentum great enough that the shock cord connection ripped off the cone. The same thing happened to me when I added 34oz. (YES!) of nose weight to a LOC cone and I depended on the plastic loop. What was I thinking? Well, I wasn't. :-( That would be my concern. I would beef that up somehow.
Len Bryan
Reply to
Len Bryan
You might want to do a ground test with rocket clamped securely. The Sumo 9 oz nose cone ejects with .7 grams of BP and a piston to a height of about 20 feet, and about 15 feet without a piston configuration (and that is dragging a 42" parachute and cord). I don't know how much charge is in an Estes motor, but I bet it will work o.k. if they all fire at the same time. I wish I had done the ground testing first before showing and launching the rocket and having it not eject before adding a piston. (Nose cone was molded heavy for balance also)
Robert
Reply to
Robert

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