Besides being an excellent supplier of parts and custom items, Balsa Machining Service has a small line of kits.

These kits are clones of 'classic' rockets from the past.

One of these kits is a Estes Astron Cobra. The Cobra was a three-motor cluster model. The Cobra's first catalog appearance was the 1964 Estes catalog, the last was the 1973 catalog.

The kit was a straightforward build, the laser-cut fins speeded up the construction. I added a piece of 'all-thread' screw between the three motor tubes which, along with a washer and nut, will provide positive motor retention.

I finished the model in the paint/decal scheme from the 1971 Estes catalog. Decals by Excelsior Rocketry.

My plan is to build a Thrustline Estes Ranger clone and a Semroc Scrambler, all finished in their 1971 Estes catalog schemes. After I have all three finished, I'll take some pictures and then go fly them!

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Bob
S.A.M. # 0014

Make sure to take some of your BSA bulk motor packs with you. That's a lot of motors!

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Scott D. Hansen
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WOOSH NAR Section #558

One of the shortcomings of bulk packs is that they usually come with medium delays. But when you're flying a 3-motor cluster, long delays are preferred, IMO. So the recovery system needs to be rigged to tolerate early deployment.

Doug

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YORF member #11

Nice finish there Bob.

What brand of gloss white are you using? Gloss white seems to be problematic to running sometimes and some of the Lowe's Valspar gloss white I've been using lately seems to be more prone to runs. Plus, it seems to be causing a bit of 'crazing' on plastic parts, with a tint of 'red' showing through on red plastic nosecones and reducers, even after a couple coats (another problem I've never had before). BTW, these are vintage Centuri builds with 30 plus year old plastic parts, though the plastic nosecones and reducers appear fine (no age degradation that I can discern).

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 have all three of the kits you mention and all three are finished as you mention.
All fly great.
The Scrambler is one of my all time favorites.
The Ranger should have outlived the Big Bertha as 1, it came first, and 2, it is FAR more interesting with the cluster and payload.
The Cobra flies decent, but weathercocks more than the Ranger or Scrambler.

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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 !

Thanks, Earl.

This may freak some people out, but I used the NEW Krylon spray paint on the Cobra. I've been using the NEW Krylon since I ran out of the original formula Krylon last year. It works fine for me except that it really sprays out of the can fast! I think I used an entire can of the stuff to paint the Cobra.

I, also, prime all my models with PlastiKote Gray Spot & Fill Primer (# 466). Good stuff!

HTH.

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Bob
S.A.M. # 0014

Thanks for the info, GH.

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Bob
S.A.M. # 0014

Wow! We're on the same wavelength. I just started working on an Estes Scrambler,will do a Ranger next,both scratch-builds. After which I have a BMS Cobra that will go together.

Since y'all are talking about BT-60 based clustered rockets, let me suggest installing a modular motor system. That way, you can fly it in the authentic 3x18 setup, but also fly it with a single 24 as well as a couple other combos.

Here's what I did with my Big Bertha a few years ago. I've since installed it in several other BT-60 birds ranging from a Holverson Tangent to an FSI Eos.
http://www.doug79.com/BT60mms/

With things like Scramblers and Rangers, when you're up for a cluster, you can fly one, but when you're just wanting to load a single motor and fly it without futzing with all the ignitor prep, you have that option, too.

Doug

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YORF member #11

That's what I did with mine and it works great. I just wish mine would stop landing on pavement with all the grass at our field.

Buzz

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Quando Omni Flunkus Moritati