Do you still have the rocket? It would make an interesting clone project. Since the decals are self-adhesive paper, they could be printed on 8-1/2" X 11" sheets of white label stock. Depending on its diameter (18 mm or 20 mm--I don't recall which), it could be built using Estes BT-20 and a Wizard nose cone *or* Quest T-20 and a Novia/Starhawk nose cone.

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NAR #54895 SR

I hesitate to ask, but what was the can of helium for?

Re: the launch controller - I don't know if the MRSC had the same requirements for the launch controller (an interlock button that must be pressed and held down before the "Launch" button can be activated, and which returns to "off" when released) during the 1970's that it does today. The controller in my Estes Electro-Launch just had a small wire "safety key" that was inserted into the unit in order to arm the launch button; when it was inserted the bulb would glow to indicate continuity. The "key" stayed in the controller and kept the system armed until it was deliberately removed. All consistent with the Safety Code at the time (mid to late '60's).

That feature of the Electro-Launch played a large role in my need to replace the 4 carbon-zinc "D" cells with a fresh set for nearly every launch. Quite often in those days the igniter didn't burn through (the system didn't provide as many amps as modern systems like the Electron Beam controller do). As long as the safety key was inserted into the Electro-Launch's controller and the igniter was intact, it kept the continuity lamp lit. Quite often my friend and I would launch a rocket, track its flight, recover it, and talk about it afterward ("Wow, cool, man!") before returning to the pad and finding the lamp still (weakly) glowing. The fact that we launched on bright sunny days also meant that we usually didn't notice the lit bulb right away, either.

MarkII

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SAM # 0011

I've seen old "quick-and-dirty" launch controller plans in early model rocketry publications that used a spring-loaded doorbell button and no safety key or continuity light--the circuit was safed by disconnecting one battery clip from the lantern battery.

The Electro-Launch would have been practical with Solar igniters, and maybe even with the Centuri Sure Shot igniters that used thinner nichrome. My father took one look at the Electro-Launch system and instead bought the 12 volt version of that old FS-5 Astron Launch Controller and a wooden Tilt-A-Pad. That amount of current instantly fired even the old nichrome-and-pyrogen Astron igniters, and they always burned in two from the much greater heat. (The "pyrogen-free" nichrome wire 'in between' the igniters also worked well as plain "hot wire" igniters on those rare occasions when we ran out of the pyrogen-dipped ones due to misfires). It was also easy to make replacement safety keys for the FS-5 out of steel music wire.

The shaving cream-size can of helium in the Aeronautical Lab Kit was for the balloon experiment. The kit contained several helium balloons, a balance-beam hot air balloon experiment, a balsa hand-launched glider, a propeller-driven balsa "stick" car, a rubber-powered "stick" helicopter, a rubber-powered balsa-and-tissue model airplane called the Arctic Explorer, a rubber band-launched rocket with parachute recovery (similar in layout to the Italian Quercetti toy rockets), the solid propellant model rocket, and several other experiments that I don't remember.

__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
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http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

The bare nichrome wire was what we used most of the time. The engines came with igniters that had a thin coating of some blue-colored stuff on the middle third - not at all like the thick black pyrogen on today's Solar igniters. They were straight and we had to bend them into the "V" shape before inserting them. Maybe these became known as the Astron igniters; I don't know. At the time, they didn't have a name; they were just called igniters. The thin blue stuff was almost like paint, or thin wire insulation, and it followed the curve of the wire without cracking or chipping off when we bent them. I remember that we needed to scrape it with a knife blade to get any of it off the igniter. (I don't remember now why, but we tried to do that once.) When we used the bare nichrome, we would make a complete turn in the middle section around the tip of a pencil or pen, just like it was shown in the catalog, so that the igniter had a tiny coil right at the tip. We used tiny wads of recovery wadding as plugs to hold them in the engine nozzles, or else a strip of tape across the nozzle.

The Electro-Launch provided just enough current to fire the engine if the batteries were fresh. The main culprit there wasn't the pad or controller, though; it was the quality of the batteries at the time. I don't know when alkalines came on the market (I think it was the early '70's), but in 1967 and '68 all we had were the old carbon-zinc kind. They didn't have much reserve and they were depleted astoundingly fast by today's standards. (They had something like one-tenth of the useful life of a comparable modern alkaline battery. And they leaked! ) On a 13 year old's allowance of $1 a week (plus whatever I could make mowing lawns), it would take me almost a month to save up the money to buy 4 carbon-zinc D cells. The EL was supposed to use photoflash batteries, which were heavy-duty carbon-zinc cells, I think, but at nearly twice the price, they were out of the question for me.

So I nursed my batteries along, trying to squeeze as much life out of them as I could. I can well remember sitting at our little launch site, holding my Electro-Launch controller, and listening to my friend do the countdown from 10. As soon as he said "10," I would press the launch button and hold it down. If we were lucky, by the time he reached "0" the engine would ignite. If it didn't, he would immediately cycle through the countdown again as I continued to press the button. If it didn't ignite after 3 countdowns or so, we would abort, wait the recommended time, and check the rocket. Sometimes the problem was a misplaced igniter, and sometimes it was a disconnected or shorted clip. But many times it was neither. My friend would usually bring along some Jetex wick and a few strike-anywhere matches, just in case.

We talked about using a 12-volt system instead, but the problem was obtaining a 12v battery and transporting it to our launch site on our bikes. (No RC batteries back then!) Using the battery in Dad's car was completely out of the question, for obvious reasons. Later on, I was seriously considering getting the extra battery pack for the Electro-Launch in order to turn it into a 12 volt system, and I probably would have if I had stayed active in the hobby and had been able to hang onto the pad.

I wasn't until I became a BAR and started launching rockets with my Electron Beam launcher that I experienced nearly instant ignition of a rocket motor when I pressed the launch button. It startled me the first time that I did it, because I wasn't expecting such a quick response. And it wasn't until I started using my present 12 volt system that I began to consistently see igniters with the bridge wire completely vaporized.

MarkII

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SAM # 0011

We could buy lengths of nichrome wire directly from Estes. At the time, I didn't have the impression that the old blue igniters were anything but nichrome wire with the blue stuff in the middle. We thought that the entire igniter was nichrome. It wasn't until after I became a BAR that I encountered the "bridge wire" type of design.

I never lost mine, but if I had, I planned on just using a straightened paper clip as a replacement.

MarkII

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SAM # 0011

I think you nailed it, Mark. The Astron name was applied near the end of the line. I looked it up on Ninfinger a while back - can't recall the year the name was added - but they did append it.

We found the nichrome wire much more effective than the purpose-built igniters.

I have some of the old ones which came with some of the vintage motors I've picked up since becoming a BAR. They came as three bits of pyrogen on one ~8" piece of wire which had to be cut into the 3 individual igniters.

Unlike you, my take is that the pyrogen was brittle and would tend to flake off, but that may only be because it's 40 years old on the ones freshest in my mind

The igniter wire was so thick that it took gobs of current to heat them up. The breakthru of the Solar igniters is the narrow bridge wire between the two heavier leads - it concentrates the heat at the pyrogen making for a much better igniter.

I've had great success with the Solars. While I'm sure many of these newer ones - eg, the new Quest types - are still better, I've had good enough results with the setups I've used that I haven't felt the need for an even better igniter. But, now that I'm starting to do air-starts, that may change

Doug

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YORF member #11

We started with the little red launcher with 4 D cells, and had dismal results, likely because we never bought the special "photoflash" batteries, but (in hindsight) I'm convinced that was the key difference.

We bought the upgrade kit which let you put 8 D cells in the red box thus giving you 12V. It was a marked improvement in reliability (even without photoflash batteries).

With the initial setup, when we would get ready to launch, we would always find the 4 D cells dead. The 8 cell upgrade would invariably find us with 8 dead cells

Ultimately, we bought the Electro Launch version that clipped onto the car battery. Never had a problem after that. Dad would pull his Olds 88 right up the pad and we'd be in business

Over two decades later, I resumed the hobby with that controller, replacing Dad's Olds with a pair of 6V lantern batteries That served me well for a few years until I upgraded to a sealed lead-acid unit. But I'm still using that controller, along with a couple others I tote in my controller box.

Doug

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YORF member #11

I know we're getting a little off topic with igniters and all -
If you haven't seen it - from Wayne Hill's Rocketry Blog

http://rocketry.wordpress.com/model...gniter-gallery/

I've used them all years ago, except for the Cox style igniters.

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Hans "Chris" Michielssen
Old/New NAR # 19086 SR

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