Rocketman flanged aft closure Q.

My understanding is that any new hardware requires testing by TMT. It DEFINATELY WOULD VOID the AeroTech warranty, since we have not authorized third party manufacturing of compatible components to this manufacturer, nor have we supplied the actual dimensional drawings of detail parts which govern the proper tolerances required. Using an existing part as reference, (Oklahoma blueprint) is not acceptable by any means. The basic concept is good, but the execution is poorly planned.

Robert

The only hardware components that I ever recall as being officially certified to be used interchangably were Aerotech, Dr Rockets, and LOC. Any one else remember when Ron made AT clone hardware?

Anything else results in an uncertified motor.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Didn't the blueprints used to be posted to the web site? I've still got my hard copy from 1990.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

thought that was the case, thought maybe I missed something, thanx, Le

That NOTICE just put Rocketman OUTSIDE of "intended use".

Or usage at ANY TRA/NAR launch.

Period.

Robert Re: Rocketman flanged aft closure Q. 22 10/30/04 9:40 AM

Got an email from Gary pointing out that the blueprints posted / distributed were NOT the fully detailed blueprints licensed to Dr Rocket. I've also seen cloned hardware that clearly lacked some of the obvious safety features of the factory approved casings.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Pay attention - Jerry has appointed himselt as overseer. Jerry- did you appoint youself to TRA/TMT or NAR/S&T?

With Jerry BIG FINE Irvine in charge, that national debt should get paid down real soon.

Which safety featuers? Who maakes them? People should watch out for that.

The unauthorized clones I saw had no brand or even anodizing on them. It was nothing more than aluminum tubing of the right size with threads of the right pitch. Some were bought from a vendor, but I don't know who. Others were made by locals, and used at TRA launches (not EX).

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

As far as I know, anodizing is not a safety feature.

Correct.

Neither is the brand marking.

Details of the machined shape at the bottom of the thread may be, though... there may be features that provide for controlled failure patterns under accidental overpressure, or that prevent stress concentrations that could cause the tube to crack open under normal operatng pressure.

-dave w

I can't imagine how anyone wouldthink this has anything to d with safety.

There isn't anything special about the shape below (or above) the threads. In fact if you look at any size casings, there isn't anything to make it fail in a soecific way. Also if you see these fail it's apparent.

There is nothing mysterious, magical or special about those rear closures. Take chunk of aluminum, add threads, drill hole. Add knurls if you want to get fancy. Of course, that doesn't support anyone who can do it themselves, so add a pinch of the mysterious and wah-lah, institutionalized protectionism in a flash.

Controlled failure pattern? AT failure pattern is usually to open up like a steamed burrito.

You mean it's not a squished banana?

Which is precisely opposite of ALL, what they claim, and NFPA rules, and NAR rules, and TRA rules.

Hmmm.

God bless LMR monopolies.

More like a over-nuked hot dog.

Come to think of it, is "ends popping off" really that much less hazardous a failure mode than "tube splitting open"? I can see that the latter might be a concern with a brittle casing, but it should be comparatively benign with a tube material that will "unroll" instead of "fragmenting". (Benign for the observers, that is... the airframe may well be toast in any case.)

-dave w