Has anyone else noticed a change to the way CTI is producing 54mm motors?

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I considered "home remedies/fixes", but I believe this is a broader issue that doesn't just affect a half dozen or so motors. I think this likely affects many of the CTI motors because I've got two of them in front of me, one failure, another ready to fail...
Maxwelljets made a great point above that a paper liner is likely not going to stand up to the heat and pressure of a 3-4s burn no matter the impulse. I agree.
 
SammyD said:
I read through the first 1-1/2 pages of this thread, and still really couldn't figure out what the OP is getting at. The J-244 I opened this weekend had a newish looking cardboard liner that I didn't recall from previous 54mm J-244 reloads, but that could be my senility keeping me from recalling correctly...

I did, however, have a 54mm CTI reloard failure this past weekend with a motor date-coded November 23, 2018. What scares me is that I have another just like it with the same date code that I'm now afraid to fly as I don't want to destroy another reload casing...

In short, the liner of a CTI J-244-WT burnt completely through in two places, one near the rear of the motor, one near the front of the motor, but both well inside the O-ring boundaries of the reload. There was also some sort of failure of the nozzle area that I can't even properly describe: there is now what appears to be the beginning of a separation of the actual nozzle from the nozzle housing if that makes sense. See the attached PDF full of photos and notes for more.

Last but not least, I can't get any link I've found for MESS reporting to work.............. :-\
Click to expand...

Great documentation Sammy, I was planning on flying the J244WH this Sat? I won't have the load in my hands till Sat but I'll have to take a look at the date and liner, may even switch to one of the other 2G loads.
 
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GaryT said:
Great documentation Sammy, I was planning on flying the J244WH this Sat? I won't have the load in my hands till Sat but I'll have to take a look at the date and liner, may even switch to one of the other 2G loads.
Click to expand...

I can't tell you Gary if the the load would fail or not, but I had two of them (purchased together) that look identical and even have exact same dates on them (November 23, 2018). One of them failed to the point that had the grains burned another second or so, I would have been cooking the motor mount, fin can, centering rings, and likely the main airframe.

I won't risk flying that other J-244, and I'm also going to be looking MUCH more closely at the CTI liners. Like I said above, I didn't think much about certain things on CTI motors because they just didn't fail. I guess that's not the case any longer, or maybe I just need to be more observant... still not sure that would have helped with the J-244 though :-|
 
SammyD said:
jahll4,

I've been down that path before. In my case, this particular motor was shipped with a pellet in the top grain and an e-match, at least I assume so since the date code is the exact same day as the other J-244 that I just opened to take these photos. I do recall (since I only flew twice with the same rocket that day with one CTI and one Aerotech motor) that the CTI used the coiled e-match, just like the one shown in these photos here.

Looking at these photos, one can clearly see the change in liner material that CTI used on this motor, and you might be able to see where the nozzle appears to be a separate, maybe pressed fit and glued, part that is inserted into the nozzle housing that contains the rear O-ring. In my mind, that sort of construction would be a weak point. Looking at 4 photos around the circumference where the nozzle goes in, there is a wider gap on side versus the other (alignment issues?). Again, looks like a weak point to me...

In any case, this combination destroyed my 3G CTI case - the spacer survived the flight...

Sam
Click to expand...

Your pics match up with what I would expect in a CTI 1 or 2G 54, but I have noticed a change in the liners as well (see video). CTI's dipped "igniter", as packaged, looks almost exactly like the normal coiled ematch in the packaging because they tuck the dipped portion underneath the coil. This is why the change went unnoticed until opened.

I have stated before, but again here for the record I'm not bashing CTI. They have been great to me, sponsoring a school project, attentive, no CATOs, etc... CTI is the only thing I fly in HPR. I plan to go on flying CTI, which is why I'm making the effort to document and contribute to this thread. I simply want them to get their issues fixed, which count 5 that have impacted my flying in the last 3 years, not 5 motors 5 different issues.

https://www.dropbox.com/s/zzqncjgtzx08xza/20191028_103124.mp4?dl=0
 
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Nytrunner said:
You can try the Jim Jarvis fix

30 minute epoxy (or 5 min on the field) around the liner/forward closure interface. I've used that on Red Lightning 54's with the brown liner and had no issues.

Although it looks like you'd need to do it on the aft closure too
Click to expand...

Liners can't withstand the pressure of a burn. If you epoxy both the forward and aft closure in, you turn the liner into a pressure vessel and rupture it, resulting in a burnthrough. This is just an issue of insufficient liner material, plain and simple.
 
jahall4,

That video is EXACTLY what I'm thinking with one exception: I don't think the igniters are causing that burn-through. The spirals CLEARLY indicate that this liner is made of paper. Paper burns quickly and easily, unlike the phenolic liners. I couldn't put my finger on the issue since I haven't flown much in the last year, but when you showed the "old" motors with the blackish colored liners, it came tumbling back to my memory. I thought to myself: "That is what the CTI liner SHOULD look like!"

The paper liner is, in my humble opinion, the single largest issue, allowing burn-through, and ultimately failures of the hardware. Though I've heard nothing about this to date (maybe I'm the first that's had this burn-through issue destroying one of my hardware casings), there have to be more of these out there. That, too, is exactly what I communicated to CTI in my email this morning.

I have heard back from CTI already, essentially an acknowledgement of this morning's email and that they were passing it along to the right person. I know both of these folks at CTI from past correspondence and trust that I'll have some sort of explanation in a few days.

Great video too! That is very illuminating... :) Oh, and FOR THE RECORD, I'm not bashing CTI either; I fly them 90% the time and have over $15,000 in motor inventory from them right now. But this concerns me big-time! I am NOT interested in putting $50, $100, $200, $300, $400, and $500 casings on the "TEST" block to see if CTI's new paper liners are going to hold up. It makes me nervous to fly ANY motor of CTI's with the paper liner...
 
Yeah, liner burn through is definitely NOT the fault of igniters. The only cato an igniter could possibly cause is an instant overpressure if the igniter is way oversized for the motor it's trying to light.
 
Sorry I didn't mean to imply that there is direct causality, but if the motor burns differently (hotter/faster) because of the mis-formulated pellets (know issue w/CTI on the 38s) then it may be contributing to the problem. Looking at my liners the burn through was at the forward end. Like Sam I'm convinced had CTI been using the old black liners we would not be having this discussion.
 
SammyD said:
jahall4,

That video is EXACTLY what I'm thinking with one exception: I don't think the igniters are causing that burn-through. The spirals CLEARLY indicate that this liner is made of paper. Paper burns quickly and easily, unlike the phenolic liners. I couldn't put my finger on the issue since I haven't flown much in the last year, but when you showed the "old" motors with the blackish colored liners, it came tumbling back to my memory. I thought to myself: "That is what the CTI liner SHOULD look like!"

The paper liner is, in my humble opinion, the single largest issue, allowing burn-through, and ultimately failures of the hardware. Though I've heard nothing about this to date (maybe I'm the first that's had this burn-through issue destroying one of my hardware casings), there have to be more of these out there. That, too, is exactly what I communicated to CTI in my email this morning.

I have heard back from CTI already, essentially an acknowledgement of this morning's email and that they were passing it along to the right person. I know both of these folks at CTI from past correspondence and trust that I'll have some sort of explanation in a few days.

Great video too! That is very illuminating... :) Oh, and FOR THE RECORD, I'm not bashing CTI either; I fly them 90% the time and have over $15,000 in motor inventory from them right now. But this concerns me big-time! I am NOT interested in putting $50, $100, $200, $300, $400, and $500 casings on the "TEST" block to see if CTI's new paper liners are going to hold up. It makes me nervous to fly ANY motor of CTI's with the paper liner...
Click to expand...

Glad I could help. I feel the same but it took CTI a month to tell me the "change" in the J430s was a production mistake so good luck :( Please let us know how this turns out for you. Since I've seen the same thing with 2G 54s I have opened and inquiry as well, so maybe we will both hear something positive soon. The is a quintessential example of why the MESS needs to be searchable. If I had not posted and you had not contributed to this thread no one may have known others encountered this issue.
 
What was the date on all those motors shown in your video that had the spiral wound liner?
 
mis-formulated pellets (know issue w/CTI on the 38s)

CTI actually said that the formula (recipe) they've used for X Amount of years was made incorrectly? that the ratio of each ingredient was somehow wrong on this batch? I just find that hard to believe.
 
Ahhh ok CTI was using 3rd party pellets... That I can see being/causing a problem, I had thought that CTI was still! making their own pellets.
 
jahall4 said:
The 2 with pellets: 11/21/2017
The 2 w/o: 12/07/2018
Click to expand...

That's weird to me in the sense that you had two 54mm motors with spiral-wound liners (let's just call them paper if we could, cause that's what they are) that had the pyrodex pellets and two without, but the two without were dated later. I say that's weird because my two J-244 motors (54mm) with paper liners both had and have the pyrodex pellets.

In short, two motors with pellets, then two motors without pellets, then two motors with pellets. You know what, I need to go open the J-430 I have onhand and see what it's got inside.

Standby....
 
SammyD said:
(let's just call them paper if we could, cause that's what they are)
Click to expand...

I'm not certain that it is paper. I think there's a chance it might be a spiral wound low-grade phenolic similar to ARR liners or PML body tubes. It's been a while since I've used one with that style of liner though, so it certainly could just be cardboard/paper.
 
SammyD said:
That's weird to me in the sense that you had two 54mm motors with spiral-wound liners (let's just call them paper if we could, cause that's what they are) that had the pyrodex pellets and two without, but the two without were dated later. I say that's weird because my two J-244 motors (54mm) with paper liners both had and have the pyrodex pellets.

In short, two motors with pellets, then two motors without pellets, then two motors with pellets. You know what, I need to go open the J-430 I have onhand and see what it's got inside.

Standby....
Click to expand...

Not so weird if my J430s (the last two) really were mis-produced like CTI had advised. And yes please check and report back with the date code I'd love to pin this down.
 
Maxwelljets said:
I'm not certain that it is paper. I think there's a chance it might be a spiral wound low-grade phenolic similar to ARR liners or PML body tubes. It's been a while since I've used one with that style of liner though, so it certainly could just be cardboard/paper.
Click to expand...

It's probably some type of Phenolic, just not the "burn proof" ;) black liners that perform so well.
 
Ok, I just cracked open my factory-sealed CTI J-430WT, but the production date is October 29, 2012 - yes, you read that correctly. It's seven years old.

With that said, it has the paper/spiral (deference to the possibility that is low-grade phenolic), an ematch with no extra pyrogen, and a pyrodex-type pellet in the front of the top grain.

So.................., that confuses the hell out of me. I need to go make a cocktail and reevaluate this tomorrow.

S

IMG_6617.JPG IMG_6618.JPG IMG_6619.JPG IMG_6620.JPG IMG_6621.JPG IMG_6622.JPG
 
White thunder is CTI's second fastest burning propellant, so there's a chance it's fast enough that the low grade liners are ok with it. Like I mentioned earlier, Vmax motors have all used that style of liner. On the other hand, the J244 you had the problem with absolutely should not be fast enough to get away with that style of liner. I know this is a long shot, but if you had an older J244 to compare to, that would be helpful.
 
Maxwelljets said:
White thunder is CTI's second fastest burning propellant, so there's a chance it's fast enough that the low grade liners are ok with it. Like I mentioned earlier, Vmax motors have all used that style of liner. On the other hand, the J244 you had the problem with absolutely should not be fast enough to get away with that style of liner. I know this is a long shot, but if you had an older J244 to compare to, that would be helpful.
Click to expand...

That make some sense, but why would I218 (1G BT) use the better black stuff? Regardless the white liner clearly not adequate even for the WT J430 if it is burning through.
 
could be a 'piece', left over from a stick of phenolic liner that would other wise be thrown away?

Tony
 
jahall4 said:
That make some sense, but why would I218 (1G BT) use the better black stuff? Regardless the white liner clearly not adequate even for the WT J430 if it is burning through.
Click to expand...
If I were in charge, I would use the black liners. Regardless of whether or not I personally think it's a good idea, there is evidence to support the fact that 2 grain white thunder motors have been using that style of liner for years. The J244 on the other hand, seems to me like a production mistake may have been made. If there are previous J244s to examine, that could clear it up.
 
Maxwelljets said:
If I were in charge, I would use the black liners. Regardless of whether or not I personally think it's a good idea, there is evidence to support the fact that 2 grain white thunder motors have been using that style of liner for years. The J244 on the other hand, seems to me like a production mistake may have been made. If there are previous J244s to examine, that could clear it up.
Click to expand...

Agreed, but I don't have any - just don't remember EVER seeing a light tan colored paper liner in a J244... one of my FAVORITE motors!
 
FWIW.

I flew the CTI 2G 54 J244WH yesterday, had no issues with the case, liner or performance. Manufacture date was 3/3/2019. Liner was the standard paper wrapped in the clear film. Ignition was pyrogen pellet and E-Match
 
GaryT said:
FWIW.

I flew the CTI 2G 54 J244WH yesterday, had no issues with the case, liner or performance. Manufacture date was 3/3/2019. Liner was the standard paper wrapped in the clear film. Ignition was pyrogen pellet and E-Match
Click to expand...

Thanks! Good to know, the manf date makes your observation very interesting, suggests maybe CTI did make a production mistake and has not eliminated the use of pellets in 2G 54s. There should be an industry supported system for reporting motor success as well as failures, maybe someday, what we have now is just a mess ;-)
 

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