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  #1  
Old 10-02-2019, 08:44 PM
KILTED COWBOY KILTED COWBOY is offline
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Default Boyce Saturn V cluster

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
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  #2  
Old 10-02-2019, 09:19 PM
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tbzep tbzep is offline
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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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  #3  
Old 10-02-2019, 11:55 PM
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dwmzmm dwmzmm is offline
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I flew my Estes K-36 Saturn - V five engine cluster with a D12-3 core, four C6-3 outboards in 2009. Model weighed in at 1 lb, 3 1/2 oz fully loaded. Boost was swift and strong, really nice altitude achieved. However, the three second delay proved too short as the model was still travelling at a high rate of speed at that point. The five second delay of those motors should have allowed the model to coast nicely to a higher altitude for better transition for recovery system deployment. BTW, I did use the Centuri clear slip on fins to ensure proper stability for flight.
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Old 10-03-2019, 08:04 AM
KILTED COWBOY KILTED COWBOY is offline
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Thanks y'all.
The fin can weighs 5oz.
I though I have to put a thrust ring inside the motor tube?
The retention for the center motor is the screw on type.
Without a thrust rig will the motor not just shoot up the tube?
Or are you thinking friction fit motor.
Could I not just figure out the length of the longest motor I will use and use motor blocks
for smaller motors.
Just have a lot of questions. I have only built Estes and Quest models out of the box.
This is my first time attempting customizing.
Alex at Boyce told me to weigh the rocket without motors after balancing and he could give me some motor options.
I don't know if any of y'all have used them, but the after sales service has been outstanding.
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Old 10-03-2019, 09:11 AM
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You will need a thrust ring for all Black Powder motors. I would set the thrust ring for the longest BP motor on the market, that way you can use a spacer for shorter BP motors on smaller fields.

With the 24mm center motor setup. If that is the case, then what I just mentioned works best. Set it up for E motors, use spacer for D motors, and it will still work for aerotech motors to.

Aerotech reloads have a lip, so you donít need a thrust ring with them. Also, you could put a 1/8Ē ring of tape on a BP motor,s aft end and build it up so it want slide all the way into the motor tube and not glue in a thrust ring if you want.
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Old 10-03-2019, 10:40 AM
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I use a D12-3 core with 4 A8-3's gets about 275' short drift, with little wind. If the wind is 10 mph or under I use a D12-5 with 4 C6-5's gets about 475'-500'. I build heavy.

DO NOT MIX EJECTIONS! Keep them the same on all engines.

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Old 10-03-2019, 01:38 PM
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A slight diversion to talk about thrust rings since I haven't built a cluster Saturn or used any Boyce aftermarket products.

3-4 wraps of quarter inch around the aft end of the motor will prevent forward movement during the thrust phase when seated against the motor tube.

2-3 wraps of half inch around the end of the exposed motor tube and motor will prevent aft movement when the ejection charge fires.



FWIW, I would probably use the kit hook and thrust ring for the 24mm center and buy or make some hooks and rings for the 18mm outboards. Maybe less flexibility but one less complexity point. Old windshield wipers are a good source of flat spring steel.

Hope this helps.
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  #8  
Old 10-03-2019, 02:44 PM
KILTED COWBOY KILTED COWBOY is offline
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Quote:
Originally Posted by samb
A slight diversion to talk about thrust rings since I haven't built a cluster Saturn or used any Boyce aftermarket products.

3-4 wraps of quarter inch around the aft end of the motor will prevent forward movement during the thrust phase when seated against the motor tube.

2-3 wraps of half inch around the end of the exposed motor tube and motor will prevent aft movement when the ejection charge fires.



FWIW, I would probably use the kit hook and thrust ring for the 24mm center and buy or make some hooks and rings for the 18mm outboards. Maybe less flexibility but one less complexity point. Old windshield wipers are a good source of flat spring steel.

Hope this helps.

This kit comes with motor retainers for the 18 and 24 mm motors. And plugs for the 18mm when not in use. My concern was foward motion in the tube on ignition. Wrap idea sounds good. Thanks appreciate all the help
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  #9  
Old 10-03-2019, 02:53 PM
samb samb is offline
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Quote:
Originally Posted by KILTED COWBOY
This kit comes with motor retainers for the 18 and 24 mm motors. And plugs for the 18mm when not in use. My concern was foward motion in the tube on ignition. Wrap idea sounds good. Thanks appreciate all the help


Aha, the Boyce kit right ? Very complete then. I'm guessing you'll need to experiment a bit with the tape width, maybe less than 1/4 inch.
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  #10  
Old 10-03-2019, 04:45 PM
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I'd use a central 24mm Aerotech E30T with 4 18mm D21T's outboard.
120n-sec of FUN !
THAT'S power worthy of the name SATURN !
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