Level 1 Cert Attempt CATO

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firemanup

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Went to a nice organized launch yesterday. Took two possible Level 1 cert rockets with me.

Figured if I had the opportunity to find a 29mm H motor for one of them I'd give the old cert a try.

Well after flying half a dozen flights an H238T was offerred, so I decided to jump on the opportunity.

Had already launched the 3" BSD Horizon on a G35 for a beautiful flight so decided to go with the 3" BSD Sprint for the cert flight.

Was a little windy but the motor had plenty of punch off the pad so wasn't too worried about that, and we had plenty of room for recovery.

Loaded up the motor, and double checked everything, started getting worried when people commented too much on how nice the rocket looked.... LOL

Got it on the pad, and then had a long wait for a hybrid motor to get ready and flown then I was up.

5, 4, 3, 2, 1,...WOOSHHHPOP.....

Had a delay blow by and the ejection charge fired in mid burn.. a very quick flight to say the least.

So the "beautiful" rocket came down in three pieces. Booster section core sampled, chute floated away with the shock cord, and the payload came down undamaged.

Will need a tube coupler, section of body tube and some new decals and it will be repairable.

The tube is crushed/kinked for about the top four inches, and then again above the fins for about a 5" section.

There was some discussion about where the delay spacer went, fore or aft of the delay grain, we placed it fore and i think we had it turned around backwards, not sure if that would cause the blow by or not.

Disappointing at first but kinda funny now, I did however learn a bit and will have some fun repairing, will be my first major repair job so it's good to learn it.

Only draw back is that my brother will be attempting next weekend so I won't get to beat him to the Level 1 cert.

Oh well, there's always Level 2 to beat him to.

Here's the sprint before the fatal flight.. heh heh

Jason


<img src="https://members.aol.com/rocketcollector/images/sprint5.jpg">
 
Sorry to hear that your cert attempt didn't pan out. You've an excellent attitude about repairing and moving forward with your next attempt. Keep up the good work. You'll be certed before ya know it. ;)
 
Bad luck Jason but good luck for your next attempt.
 
What reload did you use? Did it have the new Plus style delay grain, or did you use the older, less reliable delay grains?
 
Jason.... Hang in there buddy.... You will nail it on your next attempt!

Cutt~
 
Date on the paperwork in the reload shows Mar 2001... i'm not familiar enough with them yet to know the difference between the types of delays..

It was an Aero Tech H238T casing was Dr. Rocket

Jason
 
Ok, either two things could of happened, you used the older delay system (delay grain cast in paper) which can fail if not loaded properlly or loaded for an extended period of time, or you got the new delay system (cast in clear rubber). Around that time, Aerowrech recalled the delay grains for certain Blue Thunder loads. The reason was a chemical from the Blue Thunder propellant absorbed into the insulator of the delay grain (turning it yellow). This cause the delay grain to burn way to fast for a safe flight. Do you have a video of the flight. I could probabily tell by that. If this is the case, this failure * may * be covered by Aerowrechs warenty.
 
Okay, it was cast in paper - was it in it's own plastic bag, or just loose with the rest of the reload kit? They changed it to package it in it's own bag to keep it from reacting with the blue thunder propellant...

Loopy
 
The paper grains did not have that problem. Their problem was if the paper pealed back from the delay grain, it would burn faster. It was tricky inserting the delay grain into the liner without raising a corner of the casting paper. Also the only seal offered was the single small o-ring placed on top of the delay grain. It only seals if there is pressure pushing the delay grain upwards. This is not reliable. The Rubber delay grains are so much better. The main o-ring is on the side of the delay grain, and has a snug fit between the delay grain and the delay well in the closure. This ensures a very solid seal, since it holds the delay grain in place even when you remove the liner tube. Also, the rubber tube acts as a seal too. The heat of the motor operating causes it to expand, greating a seal between the dealy grain and liner tube. I love examining the delay parts after flying them, and seeing the grove caused by the rubber sealing itself to the o-ring.
 
Well a little CATO didn't hold us up.... here she is again fully repaired and ready to go.

<img src="https://members.aol.com/rocketcollector/images/repaired.jpg">

Jason
 
Delay spacer goes aft of the grain. Putting it fore could definitely cause a blowby. Also, I agree with Carl. Great looking rebuild!
 
Jason,

She looks like nothing happened. Beautiful job!

sandman
 
Jason,

Sorry to hear about your first flight problems but you look to be all set for your next attempt...that is one "beautiful" looking rocket. Great job on the repair work.

Best of luck to you, I'm sure it will all work out this time. :)

-Janet
 
You did a great job on the repair, and your attitude's incredibly good, Bro...
And I happen to know your brother didn't get to his Lvl 1 attempt either... 20+ mph winds kinda take the wind right out of your sail..or rather...they DO fill a sail well...., errr...you know what I mean...
I keep tellin' ya we gotta meet in the middle and do it together.

Matt Vennard
NAR#82292
 
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