Re: When did NAR Motor certification begin?

"Mark Johnson" wrote in news:biimsi$gga$ snipped-for-privacy@news.lsil.com:

At least 1962. The motors I was using then were NAR certified.

len. even older fart rocketeer.

One fart out farts another fart. Impressive young Jedi.

The motors I was flying in 1966 were all NAR certified.

Jerry

Mark and that story is.........?

shockie B)

Here's the story, as I heard it from reliable sources:

Mini-Max motors were produced at Centuri and pressed on a pneumatic arbor press arrangement, six or eight at a time. Unfortunately, the press was set up so that all of the several rams were fixed together, possibly on a single air cylinder. When the feedback mechanism indicated that a sufficient pressure had been reached, the rams all retracted.

Unfortunately, as we all know now, BP, particularly damp BP, is notoriously not consistent. When the first motor reached the proper compression, there might be others on the same batch that still had voids. These motors, of course, would generally cato either on a test stand, or worse, in somebody's rocket if the lot-sample happened to be one that passed.

Rather shortly after Centuri bought out RDC, in the course of moving Enerjet production to Arizona, Mr. Enerjet, Irv Wait, saw how the Mini-Max motors were being produced. He was instrumental in changing the multi-motor press so that each individual ram would reach the correct compression level on its own, insuring that all motors were pressed properly. The Mini-Maxes were NAR certified at just about the same time as the Centuri Enerjets. Both were in the 1971 Centuri catalog.

mj [Used to know Irv Wait during the RDC and early Centuri-Enerjet days. Haven't seen him since 1995.]

Mark Johnson wrote a great post about Mini-Max motors.

Just to add a bit: While both were in the catalog, this would be the last year for Mini-Max.

Doug

I've got a copy of NAR Technical Report #14 on the Estes Series I engines that says they're certified and says "First Issue May 1962" at the bottom. By 1964 the list included engines from Central Rocket, Centuri, Coaster, Estes, Model Missiles, Propulsion Dyamics and Rocket Development with a note down the bottom saying the American Telasco was no longer importing Jetex engines. I also found another page that lists NAR approved engines from American Telasco, Estes, and Model Missiles and it appears to be dated 1961.

I'm somewhere between Mark and Len on the old fart scale.

Bill Spadafora

thanks to the "old fart" modelers......just don't stand too close....heheh shockie B) semi-old fart .....

You're not an old rocket fart, until you hear: YOU'VE GOT GAS! when you check your AOL email account.

Randy

"shockwaveriderz" wrote in news: snipped-for-privacy@comcast.com:

See, the thing about old farts, as opposed to new farts, is the old farts are already dissipated. It's the new farts that offend.

len.