motor storage question

Hi everyone,
In April of 2005, I built an Aerotech I211 motor to be used in an airstart. The igniter fell out and the second motor never lit. I gave
it to a friend to store (it was a complete motor in the casing, not a reload kit, just to clarify) until the next lauch which is June 17th. He forgot to put it in his stoage box, and so it was left in his garage, but was protected from the rain.
My question is, should I trust to use this motor, or should I just get a new motor to avoid the possibility of a cato?
I dont konw what could happen to a motor that is stored this way over a short period of time, but like I said, it was NOT exposed to any rain or water.
Thanks a lot,
Tom Sak
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TJ wrote:

The military and NASA store rocket motors for years. Why would your motor CATO just because it was assembled a month ago? Cesaroni motors are assembled at the factory. That does not cause them to CATO when used a year later. I've assembled AeroTech motors many months before use.
Dean
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motors do 'go off' if left out of the packet for too long (see my post - salvaging old motors'. The propellant turns a light grey colour and doesnt burn very well (almost doesnt burn at all). It can cause a cato in that the motor takes too long to come up to pressure and so the rocket does not have sufficent speed to fly as it leaves the rail (this happened to me last week). If you pre assemble, try and use the motor within 3 months.
Thats my personal experience anyway. Im sure others will have different experiences.
Paul
Perth Advanced Rocket Club - Western Australia http://waro.iinet.net.au/parc /
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if you see any of that light grey "oxidation", just take a piece of fine sandpaper and lightly sand it off and the motor should then be fine to use..
shockie B)
wrote:

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In order to do that, you'll have to disassemble and reassemble the motor. If it's just been a month or two, I'd waste an ignitor trying to fire it first.
If you DO disassemble ANY Aerotech reload, you must take it ALL THE WAY apart back to the original kit form, and CLEAN all the ejection seal O-rings that have been contaminated by BP, then relube and reassemble. One spec of BP on an O-ring in the wrong place can lead to a CATO.
    Bob Kaplow    NAR # 18L    TRA # "Impeach the TRA BoD"         >>> To reply, remove the TRABoD! <<< Kaplow Klips & Baffle:    http://nira-rocketry.org/LeadingEdge/Phantom4000.pdf www.encompasserve.org/~kaplow_r/ www.nira-rocketry.org www.nar.org
    Voting for "the lesser of two evils" is still voting for evil.
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Impakt wrote:

get
motors
used
use.
post
and
cato
That's not a cato. A cato is when the motor casing or bulkhead fails due to over-pressure.

I've had some that were assembled a year or more before I got around to using them. Remember, an assembled reloadable motor really isn't much different from a single-use motor, and those can last for many years before use. The main difference is the o-rings, which can lose their elasticity over time. If you assemble a motor with the intent to store it for later use, it's a good idea to slack off the aft closure just slightly to take some pressure off the o-rings, then retighten it prior to launch. Since this fellow's motor was assembled only a few weeks ago, he's shouldn't have any problem with it.
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I beg to differ. A cato is ANY motor failure that causes the rocket to not perform in the manner intended. Including short/bonus delay.
    Bob Kaplow    NAR # 18L    TRA # "Impeach the TRA BoD"         >>> To reply, remove the TRABoD! <<< Kaplow Klips & Baffle:    http://nira-rocketry.org/LeadingEdge/Phantom4000.pdf www.encompasserve.org/~kaplow_r/ www.nira-rocketry.org www.nar.org
    Voting for "the lesser of two evils" is still voting for evil.
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kaplow snipped-for-privacy@encompasserve.org.TRABoD (Bob Kaplow) wrote:

This should be in the FAQ.
--
Jerry Irvine, Box 1242, Claremont, California 91711 USA
Opinion, the whole thing. <mail to: snipped-for-privacy@gte.net>
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At a launch last year Roy Hicks flew an AT WL I motor, which like yours had been in the top stage of a 2-stager but hadn't lit. The motor had been kept assembled, I'm not sure how long for but my best guess is from K-LOB '03 (end of Sept '03) to Big EARS '04 (May '04). It worked just fine :)
http://www.bobarnott.com/images/Rocketry/EARS/Big_EARS_2004/tn/0163.jpg.html
AT WL is known to oxidise over time, making it hard to light.
Check out this sequence, this was an old K550W. Note how many frames between ignition and liftoff.
http://www.bobarnott.com/images/Rocketry/UKRA/2004/Kone_of_Koncern/tn/0245.jpg.html
--
Niall Oswald
================================
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Thanks for your help everyone. I have had a few catos in my rocketry exsperience and I HATE them. I just wanted to check to make sure that over a short period of time, that the components of the motor wouldnt exspand or contract, allowing gasses to get where they are not supposed to be.
Tom sak
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TJ wrote:

a
get
You have nothing to worry about. Motors can be stored fully assembled with no problem, for many months. From a reliability standpoint, it doesn't matter how it was stored as long as it didn't get wet. In the worst case, you'd just have a harder time lighting it. Age isn't going to make it cato.

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