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Loc Magnum 54-6-29

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JDcluster

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I've thought I would do more of an old school Magnum cluster.
It was a Magnum 3E but with a different motor mount.
As the title says; 1 core 54 mm and 6 x 29 mm outboards.
The motor tube it came with was a little shorter than I had hoped 17" I replaced it with a 21" PML tube.
Magnum54629mount.JPG
 

JDcluster

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CRfins54629.JPG

The tubes you see are just dry fit as I had to do a little sanding to knock off the laser dust.
Next steps involved gluing the 54 mm motor tube to the Aft CR.
The middle CR laying on top of the fin was dadoed using my original Roto Zip to lock in the fins.
In hindsight; I should have did both CR's too late now.
The outer holes you see in both rings are for conduit placement for outboard wiring.
The fins were notched as I like to pull the fins to the end of the booster tube.
Magnum54629fin1.JPG
 
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JDcluster

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Well, I didn't know that the posts become locked after a certain period of time...
I now have the fins glued to the main 54 mm tube with wood glue.
In this pic you see that I swapped the LOC 29 mm tubes out for vintage PML tubes that I've had for quite some time...
MagnumBoostertubes.JPG
 

Nytrunner

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Cool stuff!

Yeah, some folks are blessed with editing afterwards, the rest of us are stuck looking silly with blank posts
 

Andrew_ASC

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I just post as I go. Anyways nice build so far. Are you going to airstart the 54?
 

cerving

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I'd launch with the 54, then light two outboards each at three time intervals. If you pull it off, you're the god of airstart clustering... if not, well, hope you got either a good truck or good legs.
 

JDcluster

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I'd launch with the 54, then light two outboards each at three time intervals. If you pull it off, you're the god of air-start clustering... if not, well, hope you got either a good truck or good legs.
There are maybe 4 devices out there that can accomplish that.
The other option is: 2 pairs of 3. One of the reasons for the build.
 

cerving

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There are maybe 4 devices out there that can accomplish that.
The other option is: 2 pairs of 3. One of the reasons for the build.
I know one that would work... either way.
 

JDcluster

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I haven't gotten electronics layout yet.
Current specs so far:
All CR's and fins cut by LOC on their Laser CNC
All CR's and fins are 8-9 mm ply.
I wouldn't call them 3/8" as I have 3/8 ply and they are thinner than that.
I've opted for PML 29 mm tubing because its thicker and won't have to seal the edges of the tubes.
3 x 5/16" AL tubing for wire conduits from K&S metals.
 

JDcluster

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The booster internals are pretty much done.
I used some 6 oz Industrial fiberglass cloth, West Systems 105/ 206 epoxy, and milled glass for fin-to-motor tube joint reinforcement.
it's a little harder to wet out but, is easier to manage as;
CompletedboosterINT.JPG
it is a little stiffer and holds together when handling it.
 

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Syclone

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@5x7 used to have a Magnum that had 2- 38mm, 29 and 24mm outboards. IIRC he had 2 timers housed between the fins to light the outboards.
 

JDcluster

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@5x7 used to have a Magnum that had 2- 38mm, 29 and 24mm outboards. IIRC he had 2 timers housed between the fins to light the outboards.
I've seen that rocket. Was he able to shoe horn a motor tube in there without cutting the outer airframe?
 

5x7

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Both sides of the 38 mm tubes were shaved down, the outside to almost nothing, so mainly the airframe was retaining the outside of the 38mm motors. It also had the stock 29s but I though it would be fun to have 24s also because we could get Vulcan G200s and Aerotech G110s. In the picture (from about 2006) those 24s are reused Vulcan casings, Ex Gs. I made 4 large ebays in the airframe above the outboards, two that held a timer each, and a lighting circuit (for night flight at LDRS14) but it had hookups for a third timer, permanent wires from the timer bays ran down to terminal blocks in the lower bays so I could hook up outboards at the pad without messing with the timers. The bay setup let me run two conduits which made hookups easier. In 1995 when this was built it felt like we were just making up how to do all this stuff as we went along. Loving your build so far!

5x7 - 7 Motor Cluster.jpg

5x7 Staging e-bays.jpg
 

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JDcluster

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I want to use a single device for all air-start events. I'm thinking a Raven 4 or MARSA 33.
Just need to come up with a mounting platform for easy prep....
 

JDcluster

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I've been debating on how to go about the booster air-start electronics setup.
That has taken the longest. I did fiberglass the payload section with FG sleeving from Soller Composite lite fiber glass. I almost certain I'll be using a Raven 4 for air-start control.
 

JDcluster

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I tried a new epoxy with this fincan. it's thinner than West and Aero poxy. 820/ 823 from AdTech Pro Build line. That's 2 layers of glass; 4 to 6 oz e-glass and 6 oz industrial cloth on top.

Magnumfincanfg.JPG
 

JDcluster

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Lol, naturally

Let me clarify: How do you decide on the layer weights and number?
My rule of thumb is; 1 oz per inch of BT diameter or there abouts. 5.5:~ 6 oz cloth.
For the rest of the rocket; I used FG sleeving because I didn't have to worry about fin slots.
 

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