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Launch!

MDRM and other large Class 1 Clusters
Alexander Bruccoleri

Hi Folks, Estes released an updated Mega Der Red Max and it flies on 3x 29 mm motors. 3 E16s keeps it a “model” and class 1 rocket so it should be good to fly at Acton. 3 Estes F15s puts it over the line due to the propellant limit of 125 grams.


I believe 3 composite F motors and even the Aerotech G74 would keep it under the class 1 limit.


Does CMASS allow large clusters at the Acton site? If so, am I correct about the 3x G74? And last follow-up, assuming all of that is a go, can the launch system reliably ignite 3 Aerotech first fire junior igniters? I suppose we could test that but this might be well known.


Thanks, Alex

Guy Wadsworth

The 3/16 and 1/4 rod pads all have relays and 12v batteries at each pad, as do the mid-power jaw stand pads, so lighting of clusters should be no issue. Clusters are allowed in Acton as long as the the flight is a low or mid power flight, and cannot be classified as a high power flight for any reason (propellant weight, total liftoff weight, motor average impulse, etc).


Guy.

Guy Wadsworth

Additional, even 2 G74 motors would be the equivalent of an H motor, and would in fact be a high power flight, which would not be allowed in Acton.


Guy.

Alexander Bruccoleri

The total impulse limit of a cluster per NFPA 1122 and the NAR safety code is 320 Newton-seconds. That said, CMASS may have restrictions that must be followed, but you can cluster two G motors and still be a class 1 model rocket.

Guy Wadsworth

After review, I agree a G47 cluster would still be a class 1 rocket if it met all other criteria. Still, probably not a flight we would prefer to see at Acton.

Alexander Bruccoleri

Glad to confirm on the G cluster. Anyway maybe its best to ask this on a case-by-case basis. Estes just released the kit and I asked since it is right on the line.

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