Onto the next model from 1979............The Sky Hook looks simple, comes with a Bt-30 tube that is pretty thick. Once again I have to cut out my own fins.

You're on the same progression that I followed as a 10-11 year old back in 1982! I built a Der Big Red Max from a starter set, then the Kadet, and then a Sky Hook. I also recall having to cut out the fins. I lost my original Sky Hook as a teenager when I decided to fly it on a C6-7.

About 4 years ago, I built a Semroc Sky Hook and wrote it up for our club newsletter, see
http://www.mn-rocketry.net/masa/planet/masa_Vol9-3.pdf

On its first flight (A8-5), it spit the engine, caught a thermal and drifted off never to be seen again. When I built another one, I glued in a 13mm motor mount with hook to make sure that I'd never be tempted to fly it on anything bigger than an A. It flies very nicely on an A3-4t.

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https://masa-rocketry.org/

Of course, a REAL Sky Hook has a parallel-wound BT30 body tube.

Anything that I build that is based on BT-20 that comes with a parachute for recovery immediately gets the chute (ANY size) replaced by a 30 to 45 inch streamer based on the weight of the finished kit. This ensures much closer recovery and the ability to actually recover the rocket if flown on anything other than an A8-5.
I used to regularly fly my Wizard and Astron Sprint on C6-7 engines and always recovered them.
ANY chute on a Sky Hook is overkill.

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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 !

Two years ago, I got a quote from Tom Natal at New England and ordered some parallel wound BT-30's for the Golden Scouts. A few days later I got an email that told me that the machine they had now would not wind paper less than .010" thick, instead of the original .003" they used on the BT-30, so they had to cancell the PO.

We had to go to the fallback plan in which Vern, Gleda and I wound several hundred by hand for the Golden Scouts they gave away at NARAM-50. The rest were spiral wound.

Bill, they had a record that they had made some BT-30's, but they could not find a record that they had made any BT-40's (BT-1) for MMI or Estes. Do you know where MMI got their tubes?

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Carl McLawhorn
NAR#4717 L2
semroc.com

Could someone please explain this "paralle wound" or point me in the right direction for a web site to explian it.

Daniel

Wow! Vern and Gleda, out of the business for decades, rolled up their sleeves and rolled tubes with you? How cool is that?

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I love sanding.

and then GAVE them away at NARAM 50, I have mine and treasure same - it has a place in my trophy case

Same here, only mine is in the trophy pile.

S.

Carl, I think the other source was Sonoco (Pittsfield, Mass). At E.I. we used them as an alternate source for engine tubes also, but had problems because their tubes were softer than the NEPT ones, resulting in a disproportional number of catos.

As an aside--the only reason for the BT40 that I can recall is that it fit the molded fin units (which came from a fireworks company).

The anecdote regarding the hand rolled bodies for the Golden Scouts is a good illustration of the qualities of Vern and Gleda that made Estes Industries a great place to work and a great company to do business with.

--Bill