I have attached the RockSim files I created for both of these scenarios with the Estes K-39 Semi-Scale Saturn V. The CP is better with the plastic fins, 13.89" and the stability is 0.60 on a C6-5 motor, the more scale like fins give a CP of 13.26" and 0.43 caliber of stability. I simulated the 4 engine shrouds as a single transition. The more scale like fins (paper) are slightly distorted by RockSim, they are slightly larger in size, so the actual CP would be less and stability margin would be worse. I don't know of any other old Centuri/Estes Saturn V kits that have clear plastic fins and the ones in this kit don't "slip on".

Attached Files

	oop_Estes_Semi_Scale_Saturn_V_K_39 Plastic Fins.rkt (79.0 KB, 44 views)
	oop_Estes_Semi_Scale_Saturn_V_K_39 Paper fins.rkt (78.2 KB, 38 views)

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Bruce S. Levison, NAR #69055