Root Cause Help on a CTI Pro-54 CATO

[bchaltraw]

I just had a scratch-built XXXXL Astro Sprint Upscale enjoy an issue at 3000ft up. It was going awesome and then it took a hard right turn, we were wondering what happened and it was clear when I located it. This was a J295-CL 3 Grain.

 

[hprocketeer]

Model Rocketry is a safe and RELIABLE activity.. If a person does their homework and keeps up with the latest news from manufactures. This could of been avoided easly.

From a post from CTI
Pro54 2G LB motors

Sep 13 2022

Cesaroni Technology Inc has noticed that there has been a higher failure rate than normally expected on Pro54 2G SK (J145) reloads. We have been looking into this matter and have verified the anomaly which stems from an over-pressurization after ignition.

I recently experience a CATO on the pad using a Cesaroni 54mm 2-Grain Skidmark motor. The forward closure was ejected through the motor casing and out the top of the rocket and the recoil smashed the retaining ring against the launch pad standoff (I got a pretty spectacular photo sequence of the event!). It turns out that aside from the motor retainer assembly needing to be replaced, the rocket is fine. After a little motivation with a hammer and screwdriver, I managed to get the reload out of the casing. I found a little wad of some "debris" inside the nozzle. It almost looks like masking tape or a plug of some sort. The only thing I inserted into the nozzle was the e-match, so this was inside the reload when I purchased it. Does anyone know ________.....

Off My Soapbox...
Mike

 

[rfjustin]

Model Rocketry is a safe and RELIABLE activity.. If a person does their homework and keeps up with the latest news from manufactures. This could of been avoided easly.

From a post from CTI
Pro54 2G LB motors

Sep 13 2022

Cesaroni Technology Inc has noticed that there has been a higher failure rate than normally expected on Pro54 2G SK (J145) reloads. We have been looking into this matter and have verified the anomaly which stems from an over-pressurization after ignition.



Off My Soapbox...
Mike

Perhaps instead of soapboxing, you should do your homework and read what @bchaltraw noted which was "This was a J295-CL 3 Grain", which is is not a long burn 2 grain 54mm from CTI, not even close to the same motor. Different propellant, different number of grains, different burn time, different grain geometry, etc. The J295 3 grain 54 is CTI's "Classic" propellant, not a long burn sparky.

I doubt @bchaltraw could have anticipated this failure method. I sure didn't when a K-1440 killed a L3 class rocket of mine in the exact same manner...

 

[bchaltraw]

I have read all of the issues, and this is a 3-grain, J295 not a 2-grain(J145), that has been reported. This motor was also a Classic not a Skidmark or Sparky of any sort. Got back off the soapbox.

 

[rfjustin]

I have read all of the issues, and this is a 3-grain, J295 not a 2-grain(J145), that has been reported. This motor was also a Classic not a Skidmark or Sparky of any sort. Got back off the soapbox.

 

[bchaltraw]

View attachment 569947

I will upload the video it was marching awesome and then as Snagglepuss would have said! Exit Stage Left! LOL

 

[hprocketeer]

My BAD. You are correct. I was replying to an old post.. Totally different problem, but a previous thread for what must be a general cato thread. I am not used to mutiple different problems on one thread asking for help.
I should of noticed the dates of previous posts.

Sorry bchaltraw. I hope you do not think i was putting you down. A burn through at the nozzle is quite a different problem than what i posted about.
My soapbox seems to be worm ridden.
Mike

View attachment 569947

 

[bchaltraw]

Rather than start a new thread figured I'd add to this one as it's CTI related. Here is the video of the fun,

 

[Swany]

My BAD. You are correct. I was replying to an old post.. Totally different problem, but a previous thread for what must be a general cato thread. I am not used to mutiple different problems on one thread asking for help.
I should of noticed the dates of previous posts.

Sorry bchaltraw. I hope you do not think i was putting you down. A burn through at the nozzle is quite a different problem than what i posted about.
My soapbox seems to be worm ridden.
Mike

Well, unless you have some sort of Time Machine, I’m not sure how I was suppose to read a CTI memo that came out 10 months AFTER I had the issue…

 

[Howard Druckerman]

I also had a J145 CATO as described at the very top of this thread. Immediately at ignition: forward closure ejected out the rocket separation point, Aeropack retainer completely reamed, casing sitting against the pad with aft retainer now permanently attached to the casing, 2 grain propellant completely intact (a little dirty but not lit or damaged). The only difference was that I did not find anything plugging the nozzle or the angle groove to get from the off-centered hole to the nozzle.

Rocket was undamaged. MESS forthcoming.

 

[jnmiller]

I also had a J145 CATO as described at the very top of this thread. Immediately at ignition: forward closure ejected out the rocket separation point, Aeropack retainer completely reamed, casing sitting against the pad with aft retainer now permanently attached to the casing, 2 grain propellant completely intact (a little dirty but not lit or damaged). The only difference was that I did not find anything plugging the nozzle or the angle groove to get from the off-centered hole to the nozzle.

Rocket was undamaged. MESS forthcoming.

Did you remove the pellet?