CTI motors

[berlinetta]

Does anyone know if there's a date code on the problem CTI 54mm motors? I have two sealed J449s. I will have to open it up and remove the pellet if need be.

 

[Banzai88]

All of the latest bulletins are here: http://www.pro38.com/news.php

 

[crossfire]

Does anyone know if there's a date code on the problem CTI 54mm motors? I have two sealed J449s. I will have to open it up and remove the pellet if need be.

Wasn't your problem on 38mm motors. I never heard of pellet problems on the 54mm motors

 

[berlinetta]

Wasn't your problem on 38mm motors. I never heard of pellet problems on the 54mm motors

No. I never had any issues with the 29 or 38mm motors. I've been hearing about the 54s.

 

[sharkbait]

Does anyone know if there's a date code on the problem CTI 54mm motors? I have two sealed J449s. I will have to open it up and remove the pellet if need be.

No problems with the J449
The issue was with 2g long burn Skid & Red

 

[jnmiller]

The problem is primarily with the 54mm 2 grain J145 Skidmark

 

[berlinetta]

I inspected one of the J449s and found nothing loose. A couple questions I do have is this....what is the black thing that is bonded to the top grain of the motor? Also, do I need to epoxy the forward portion of the reload into the top of the reload as it is loose? I hope my questions make sense to someone here.

 

[KenECoyote]

I inspected one of the J449s and found nothing loose. A couple questions I do have is this....what is the black thing that is bonded to the top grain of the motor?

Check the second Pro38 doc in the bulletin Banzai88 noted above...

All of the latest bulletins are here: http://www.pro38.com/news.php

 

[Steve Shannon]

I inspected one of the J449s and found nothing loose. A couple questions I do have is this....what is the black thing that is bonded to the top grain of the motor? Also, do I need to epoxy the forward portion of the reload into the top of the reload as it is loose? I hope my questions make sense to someone here.

The black pellet (or portion of pellet in small motors) is a compressed black powder pellet that is pressed into the top of the top grain. It enables CTI motors to be started with a low current electric match rather than a pyrogen dipped igniter and it’s unique to CTI.
I’m unsure what component you’re referring to when you say the top of the reload is loose. The forward closure is intended to be removed in order to adjust the delay grain. It should have o-rings to seal it in the tubular liner. Some people do use epoxy when they re-insert the forward closure into the liner in an attempt to reduce the probability of a forward burn through, which is a problem that has plagued some of the longest CTI motors for a few years now. That’s only for the 38 and 54 motors and I’ve mostly just seen it on the 6 grain XL cases in both diameters.
Before you do anything I recommend downloading and printing the CTI instructions for the motor you have. CTI no longer packages their instructions with their reloads, which is the dumbest move ever made by a hobby rocketry company in my opinion.

 

[berlinetta]

If I read this bulletin right, the pellet issue is reloads purchased after 2019. Mine was purchased in 2012. I do like that modification though.

 

[berlinetta]

Post in thread 'Root Cause Help on a CTI Pro-54 CATO' https://www.rocketryforum.com/threads/root-cause-help-on-a-cti-pro-54-cato.169480/post-2207068

Anyone else try this?

 

[berlinetta]

The black pellet (or portion of pellet in small motors) is a compressed black powder pellet that is pressed into the top of the top grain. It enables CTI motors to be started with a low current electric match rather than a pyrogen dipped igniter and it’s unique to CTI.
I’m unsure what component you’re referring to when you say the top of the reload is loose. The forward closure is intended to be removed in order to adjust the delay grain. It should have o-rings to seal it in the tubular liner. Some people do use epoxy when they re-insert the forward closure into the liner in an attempt to reduce the probability of a forward burn through, which is a problem that has plagued some of the longest CTI motors for a few years now. That’s only for the 38 and 54 motors and I’ve mostly just seen it on the 6 grain XL cases in both diameters.
Before you do anything I recommend downloading and printing the CTI instructions for the motor you have. CTI no longer packages their instructions with their reloads, which is the dumbest move ever made by a hobby rocketry company in my opinion.

So I could use 5 minute epoxy for that even though it's only a 3 grain reload. I have the instructions wrapped around the reload itself with an elastic holding it on, put there by CTI. This reload was bought in 2013...manufacture date of December 2012.

 

[Steve Shannon]

So I could use 5 minute epoxy for that even though it's only a 3 grain reload. I have the instructions wrapped around the reload itself with an elastic holding it on, put there by CTI. This reload was bought in 2013...manufacture date of December 2012.

That’s what people do, but officially the only people who can give you permission to do something that’s different from the instructions are CTI customer service.

 

[Steve Shannon]

However, I haven’t seen any problems with 3 grain loads and I think 2013 was before CTI started having problems with the 6g xl loads anyway.
I would just fly it.

 

[mikec]

I think they've always had problems of various sorts with the longer loads, but I would just fly this one, especially if it has a plastic-coated paper liner instead of phenolic.