I got the scale factor of my upscale wrong.

1.04" : 1.88" = 80% upscale.

So, after sanding the filled fins, I finally mounted them. After letting a coat of yellow glue on the mating surfaces get tacky, I squirted a bunch of Elmer's white into the slots, along the body tube's inner surface.

Then, after slotting in the fin and holding it for a minute, I mounted the model so the white glue could flow and settle along the fin / inner body interface.

After all eight fins were in I let the parts sit in the roasting 95 F temps on my deck.

Fillets laid out, then more roasting.

Fabric reinforcing next.

Attached Thumbnails

     

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NAR #27085 - Oregon Rocketry - SAM

Cool project! We need more 29mm BP stagers. I've flown the PSII booster with things like the Trajector & Majestic, but they've been far too heavy. I really like the Centaur design, need to get one of my Semroc clones built.

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Paul
If we weren't all crazy, we would go insane - Jimmy Buffett
NAR #87246 www.wooshrocketry.org

Open Rocket sez that the Maxi Centaur will be stable and fly safely, but proof will be in launching! I run the simulations again once I have updated mass figures.

I built a pair of almost-minimum-diameter (Semroc 125 tubing) 29mm BP stagers that flew nicely on various E16/F15 combos. One recovery, one lost sustainer. The third flight had a staging failure. I have just enough tubing to repair the damaged sustainer and make a shorter 2nd sustainer.

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NAR #27085 - Oregon Rocketry - SAM

The Maxi-Centaur has been sitting with its sealer curing long enough!

I sanded the fins, put on another coat of sealer, smoothed over rough spots with putty, and glued on the launch lugs.

A third lug went on a booster fin. Just a little bit of extra support.

I stuffed the launch lugs with scraps of table napkin to keep spray paint out of them. Also masked off the rear inner surface of the sustainer's body tube (so the stage coupler still fits smoothly), and the exposed part of the booster motor mount (so the Estes retainer ring can get a good grip).

It is now in primer! After sanding, I'll fill in dings with putty, sand, and primer / sand again.

White body tube, black booster fins, red or orange sustainer fins.

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NAR #27085 - Oregon Rocketry - SAM

Looking great !
Looks to me like a 2-Stage Lil' Hustler.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, TURMOIL, FIASCOS, and HAVOC !

Yep, that's what I thought too (see Post 9). This is a nice design (I recently built the regular size Centaur), but have yet to paint it (I got into building a Centuri Buck Rogers Draconian Marader and the UFO Invader Super Kit).

But it is a classic Centuri design!

Earl

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Earl L. Cagle, Jr.
NAR# 29523
TRA# 962
SAM# 73
Owner/Producer
Point 39 Productions

Rocket-Brained Since 1970

I think you need that balsa sealer to dry a couple more MONTHS.

__________________
When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, TURMOIL, FIASCOS, and HAVOC !

It wasn't Aerogloss / dope sealer, FWIW. Ceramcoat sealer, water based.

Usually I DO leave filler and sealer curing/drying for months. Because I'm lazy!

But I wanted to get this build moving. I have too many In Primer projects.

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NAR #27085 - Oregon Rocketry - SAM

I hear that.
I currently have at least 9 builds in "primer" awaiting paint.
Orbital Transport, SST Shuttle, Centuti Egg Crate, Enerjet Egg Crate, Citation Patriot, Astron Sky Dart, Semroc SAM-3, Interceptor-E, Centuri/Estes Long Tom, Estes 2167 Mercury Redstone, 1/100 Little Joe II, and others.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, TURMOIL, FIASCOS, and HAVOC !

Yeah, I got a bunch too: Centuri Astro1, Aerobee 350, Saturn V, Saturn 1b, Centaur, F-15 Eagle, Skylab, Laser-X, Javelin, Buck Rogers Draconian Marauder, UFO Invader Super kit (last three not even yet in primer) and an Estes Big Bertha, Interceptor, Nike-Apache, Mini Honest John, Demon, 1/45th Little Joe II, a Semroc Aerobee-Hi and about five MRC kits that are built but not yet in primer.

I can build them faster than I can prime, sand and paint! Ain't that the way it always is?

Earl

__________________
Earl L. Cagle, Jr.
NAR# 29523
TRA# 962
SAM# 73
Owner/Producer
Point 39 Productions

Rocket-Brained Since 1970