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Old 10-02-2019, 08:19 PM
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tbzep tbzep is offline
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Join Date: Mar 2005
Location: TN
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Quote:
Originally Posted by KILTED COWBOY
Just got a Boyce Aerospace hobbies 5 motor cluster for my Estes Saturn V #1969.
Has anyone used this yet?
Got 24mm center motor and 4 18mm outer motors.
Has the fins, fairings and lower wrap incorporated in the unit.
Seems pretty straight forward to install.
Was wondering what motors to use

I'm assuming you want to stay with black powder motors for availability and ease of clustering. You are going to need extra nose weight for any of the combinations because you will be adding a lot of weight to the tail. You will be limited in motor selection if you put a thrust ring in the motor mount tubes.

A single D12 and four C6's will get you about 52 Ns total impulse (as per NAR testing), which is equivalent to a smaller F motor and should kick the Saturn pretty hard. You can use that as a base reference since many Saturn mods have used that combo in the past. You can go bigger or smaller with a C11 or an E12 center motor and you can play around with smaller 18's also.

I don't know how much weight the Boyce cluster assembly will add, but I'd bet a single D12 and four B6's will kick it's butt off the pad quick and keep it low enough to enjoy seeing the whole flight and keep it on smaller fields.

Playing with numbers, a single C11 and four A8's will get you a little over 18Ns, which is a couple more Ns more than a single D12. I don't know if that's enough to cover the added weight of the assembly and extra motors. It would be a really low and butt clenching flight. I'd say the very minimum combo would be a D12 with four A8's or a C11 with four B6's to have a safe minimum altitude flight.

The max you can do with Estes black powder is an E12 with four C6's, at about 62Ns, equivalent to a mid size F motor.

The max you can do with composite is one of the various 24mm Aerotech F motors with four composite Aerotech 18mm's such as the D21, which is a full 20Ns. The Quest 18mm D is about 18.6Ns. I wouldn't care for a flight like that because you'd need to reinforce the kit, add more fin area and nose weight, and the rocket would be a pinpoint in the sky for the majority of its flight. An Aerotech F35 with four Aerotech D13's, 15's or 21's will get you about 137Ns, which is a higher end G motor.

Decide what type of flight you want. High altitude vs lower, super fast off the pad or somewhat more normal, etc. Find out the weight of the upgraded model and let us know if you have outboard ejection blocked. Then you/we can play with the numbers for a good combination and figure out the delay needed.
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