Rocketman flanged aft closure Q.

I've never seen any claims that said any safety 'features' are machined into casings. Have you?

Yep - best one yet.

I think the ends popping would be safer because the stuff would just go straight up & down. This yeilds a much smaller splash pattern. I test my ex stuff in a hole dug with a post hole digger. If something over pressurizes, I only have to look for the stuff that went straight up. Since it only went straight up, it's much easier to find.

For those that don't know, the aluminum casings have almost no fragmentation. Many other substances can't make this claim.

Oh yes. Over and over again. Try a little google.

Here is a JI link from '96.

Yes.

I think he is referring to GCR/AT.

Although he did say "any".

That is not the point in regulatory matters. Literal words are.

Sadly.

In any case there have been manufacturer claims over the years that the ends are designed to fail to prevent either unroll or fragment.

Jerry

Easier to link, I think, he said with a wink:

Yes and no. It does prevent corrosion. But there were other features missing from the clone casings, like the stress grooves behind the threads.

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

Just like what those AT cases look like half the time when they cato:

BALONEY!

What is says about the pressure drop extinguishing the flames is true in most motors that use AP I don't consider that to be caused by a safety feature being designed into the casing.

What you are calling stress grooves are called a thread relief by machinists. It is there to provide a clean termination to the threaded area. It can be done as you described but it is not good practice.

THe anodization makes it easier to clean but weather it's anodzed or not, you should clean the inside of the casing so the orings make a good seal.

I think USR casing aren't anodized but the closures are.

Jerry - how are your sales doing in the UK?

Not missing from the versions that caused the cease and desist notices.

They are there for "appearance of compliance" only.

There are no current reloadable cases that actually comply with NFPA codes.

The problem of course is the code not the cases.

A few kits here and there, but that's about all.

Why?

Jerry

Just wondering.

I see they advertise your motors too. How are the motors selling? Can you slip in a cross cert deal?

You keep saying "my" motors.

No.

Also UK does not require club certs. God save the queen.

I saw one of those, very early in the burn, with a G125 - it looked almost like an ignition failure, except I saw a small flash of blue flame, and when I went to look at the rocket itself, then nose was ejected about 1 cm or so...

Thinking that this was a bit odd, I removed the motor for inspection... the case had cracked right at the delay assembly, which had fallen off... about

2cm of the motor was loose inside the rocket; the ejection powder and delay grain were unburned (and the powder was loose in the airframe, since the rupture had carried away a flake of the casing and opened the side of the powder chamber behind the paper seal)... the forward end of the propelllant was visible, unburned (except that the core was a little enlarged on one side where the igniter was). It looked like the failure had occured in the immediate pressure spike of ignition, and extinguished everything before there was really enough heat in the propellant surface to keep things burning after that.

-dave w

That may just reduce the flaming mess, post-failure, independent of the exact direction in which it pops open.

-dave w