Shelf life of estes rocket motors

Shelf life of estes rocket motors

Post by C. D. Tavar » Fri, 25 Nov 1994 07:20:38



Quote:

> Can anyone tell me the shelf life of estes rocket motors?
> I recently found some D class engines that must be 10-15 years old.
> Are these things flyable?

I wouldn't fly them.  Estes D's have never been the most reliable
performers in the known stable of engines.  The problem with engines
that old is that you don't know where they've been.  If they EVER got
raised to a temperature above about 140F, they'll almost certainly
wreck your model.  I have Estes D's that old in my ba***t.  I KNOW
where they've been, and I'm still ginchy about using them.
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Shelf life of estes rocket motors

Post by bill nels » Fri, 25 Nov 1994 11:44:30


:
:
: Can anyone tell me the shelf life of estes rocket motors?
:
:
: I recently found some D class engines that must be 10-15 years old.
:
: Are these things flyable?

If they have not been temperature cycled, or dropped and banged around,
they should work fine.

BP does not deteriorate very rapidly.

Bill

 
 
 

Shelf life of estes rocket motors

Post by kaplo.. » Sat, 26 Nov 1994 20:07:49


Quote:

> Can anyone tell me the shelf life of estes rocket motors?

> I recently found some D class engines that must be 10-15 years old.

> Are these things flyable?

I can't say what the upper limit is. I've recently flown 25+ year old
motors. All I can say is that they work AT LEAST as well as the current
stuff. If they were good initially, and properly stored (no exposure to heat
or humidity), they should be OK.

For composite motors, I've not noticed any problems with the propellant at
all. I have had problems with 15 year old delays, either not igniting at
all, or ejecting at burnout. I now save them for outboard motors in clusters
where the ejection isn't used.


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Shelf life of estes rocket motors

Post by robert_a_littlefie » Thu, 01 Dec 1994 00:06:27



Quote:

>I recently found some D class engines that must be 10-15 years old.

>Are these things flyable?

You didn't say how many you had, but you could take a few samples
and test fire them to see what they will do. Take an engine and bury
it so that just the nozzle is exposed, pointing straight up, and
ignite the engine the way you normally would if it was in a rocket.
If 10% of your engines fire ok, the other 90% are probably ok.

If they have been in the attic where they have been temperature
cycled, throwing them out is probably a good idea.

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Shelf life of estes rocket motors

Post by Mark Johns » Fri, 02 Dec 1994 18:56:33


Quote:

>You didn't say how many you had, but you could take a few samples
>and test fire them to see what they will do. Take an engine and bury
>it so that just the nozzle is exposed, pointing straight up, and
>ignite the engine the way you normally would if it was in a rocket.
>If 10% of your engines fire ok, the other 90% are probably ok.
>If they have been in the attic where they have been temperature
>cycled, throwing them out is probably a good idea.

Note: Test firing in this manner will result in the ejection charge blowing
the rocket motor out of the ground. This may or may not be a problem, it is
pretty funny seeing a motor play "giant Mexican jumping bean."

Our club's standard static test arrangement consists of a stake (normally a
1/4 inch launch rod) driven into the ground. The motor is taped securely onto
this stake, nozzle UP, with just enough clearance below to allow a 3-gallon
bucket of water to sit underneath the ejection end.

The water catches ejection and fireballs, and would catch the motor if we ever
had one break loose. We've used this setup with up to ancient F100's and never
had one break away to date. Fireballing C5-3's are fun - the propellant grain
bubbles madly when it hits the water.
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