CTI Pro54 Motor Reliability?

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cruck1000

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Has anyone had any failures of CTI Pro54 motors date coded around March 27th, 2018? Earlier this year I tried for L2 and I had a J760 (Mar 27 2018) CATO with a rupture near the aft end of the casing. A few weeks later I tried with a replacement of the same date code... same thing, CATO with the motor melting through the casing just above the nozzle assembly. I did end up getting my L2, on a little AT SU none-the-less :)

Frustrations aside, now I've got a K1440 I ordered at the same time with date code March 26th, 2018 (ish, the code is hard to read the "6" position on) and I'm honestly afraid to use it for then having to spend more money to rebuild the rear end of the rocket again (and honestly, I'm not sure how many more meltdowns it can take!)

I really want to love CTI, their motors are so easy to use, but with no response from their email contact system I just don't know what to do. Should I invest more into CTI motors or should I jump-ship and go with AT SU or reloads? Advice on the CTI dates and future purchases appreciated!
 
I also prefer CTI motors due to ease of assembly but I'm also getting frustrated with their lack of support. I had a CATO over five months ago. After a long delay, received an email saying I will get a warranty replacement but they are backed up because of the fire, be patient. Nothing since. In contrast, when I had a CATO with an AT motor, Karl Baumann sent me a replacement in less than a week.

I've had good success with CTI motors except for this one incident. Invest in them if you wish, but don't hold your breath if you need to make a warranty claim.
 
There’s a thread around somewhere about several CTI 54mm catos but they were prevalent to the forward end.
 
I've had problems with a few CTI 38mm motors including a crowd pleasing J425 cato, but I've never had any problems with 54mm CTI motors. And I've flown a lot of them.
 
with no response from their email contact system I just don't know what to do.
You pretty much have to go through the dealer you bought the reload from. I used to email Jeroen directly, but obviously that's not an option any more.
 
You pretty much have to go through the dealer you bought the reload from. I used to email Jeroen directly, but obviously that's not an option any more.
Yep, my vendor has been really nice about getting everything squared away but a response from CTI would be nice to see.


As for the mode of failure, both of mine appear to have been burn-through at the nozzle/liner joint, where epoxy may or may not have helped. A picture of the 2nd failure is attached below. I notice someone in the thread linked by terryg mentions this same mode of failure, like it was possibly a supply chain issue for the liners that has gone unnoticed for this date batch.
0728181258.jpg
 
Some propellants may be more problematic than others. I've had issues with Cstar and Imax and this thread is with White Thunder. Propellants that use plastic-lined paper rather than phenolic liners (e.g., Classic) are probably less stressing on the case.
 
Did you lube the case or o-rings before loading and tightening down closure. The o-rings seem to want to roll if not done. Could failure mode be an o-ring out of its groove or a reload not completely inserted?
 
Yep, my vendor has been really nice about getting everything squared away but a response from CTI would be nice to see.


As for the mode of failure, both of mine appear to have been burn-through at the nozzle/liner joint, where epoxy may or may not have helped. A picture of the 2nd failure is attached below. I notice someone in the thread linked by terryg mentions this same mode of failure, like it was possibly a supply chain issue for the liners that has gone unnoticed for this date batch.
View attachment 366433
I had a K940 loaded for about 2 years. Kept in a conditioned, dry space. When it was time to use it I disassembled it. The cement on the nozzle end had dried and it came off easily. I epoxied it back on and re-greased the forward o-ring, worked perfectly.
 
Some propellants may be more problematic than others. I've had issues with Cstar and Imax and this thread is with White Thunder. Propellants that use plastic-lined paper rather than phenolic liners (e.g., Classic) are probably less stressing on the case.
J760 definitely had the plastic-lined paper.

Did you lube the case or o-rings before loading and tightening down closure. The o-rings seem to want to roll if not done. Could failure mode be an o-ring out of its groove or a reload not completely inserted?
The first time, I didn't use anything on it. The second time I did use some WD-40 silicone spray and have an experienced flyer watch over my assembly. In both situations it was a brand new case, the motor slid in without too much resistance (I was able to push it in by hand just fine) and the aft closure was hand tightened snug. :|
 
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