CTI Discussion Thread

[Rocketjunkie]

The I100 is a moon burner for the 2 grain case. It still should have the phenolic liner. If it has a paper liner, it's a cato waiting to happen.

 

[Rocketjunkie]

That's just it, it is a 2 grain. Take a look at the video I posted.

The I100 is a moon burner for the 2 grain case. It still should have the phenolic liner. If it has a paper liner, it's a cato waiting to happen.

 

[Highpowerrocketyahoo]

So, just reporting back. I'm afraid that I can't recommend the K1200. The good news is that the forward closure held up fine. The bad news is the rear closure didn't. The motor worked fine for about half the burn and then let go. Things got interesting after that.

Jim

View attachment 583252View attachment 583253

Ouch.

 

[Art Upton]

So, just reporting back. I'm afraid that I can't recommend the K1200. The good news is that the forward closure held up fine. The bad news is the rear closure didn't. The motor worked fine for about half the burn and then let go. Things got interesting after that.

Jim

View attachment 583252View attachment 583253

Did your motor retention let go also , or did it hold the huge road flare inside the rocket torching it?

 

[jahall4]

The I100 is a moon burner for the 2 grain case. It still should have the phenolic liner. If it has a paper liner, it's a cato waiting to happen.

That's a good point, but of course suggests that CTI is using the spiral paper liners on motors where they THINK they can get away with it, but really can't.

But then why use the phenolic on 1 grain motors that don't burn any time, don't need the phenolic? Both the I218 and the J430 are White Thunder with a similar burn time making the J430 "hotter".

https://www.thrustcurve.org/motors/...23100000003a7&motors=5f4294d200023100000002da

 

[smstachwick]

The I100 is a moon burner for the 2 grain case. It still should have the phenolic liner. If it has a paper liner, it's a cato waiting to happen.

Moon burner? I've heard that around but I've never seen a definiton (forgive my noobiness)

 

[Art Upton]

Moon burner? I've heard that around but I've never seen a definiton (forgive my noobiness)

Instead of BATES grains, grains cut into sections so they burn in the core and the front & back of the grains,

A moon burning for a two grain case would be a single grain the size of two with a drill hole off the side , sorta like a Crescent moon.

Many AT motors are C-slots with a rectangular cut on one side of a solid full grain.

 

[smstachwick]

Instead of BATES grains, grains cut into sections so they burn in the core and the front & back of the grains,

A moon burning for a two grain case would be a single grain the size of two with a drill hole off the side , sorta like a Crescent moon.

Many AT motors are C-slots with a rectangular cut on one side of a solid full grain.

I see. Basically the offset core produces the "moon" shape as the burn progresses? Interesting.

 

[Art Upton]

I see. Basically the offset core produces the "moon" shape as the burn progresses? Interesting.

And that is what makes moon and c-slot motor burn for a much longer time then bates grains that burn core/top/bottom of each of the grains in your case.

AP motors really don't work well for end burning like Estes BP motors do. They started out as core burners as a long single grain with a core all the way to the top.

But that made them very progressing burning in the thrust curve and have lots of pressure at the end of the burn instead at the beginning.

Bates was then used to make the curve more neutral.

 

[Art Upton]

https://www.rocketryforum.com/threads/understanding-bates-propellant-grains.175585/

 

[Art Upton]

Bates grains also made shipping to avoid hazmat fees for easy access of motors with bates grains under 62.6 grams.

 

[rfjustin]

So, just reporting back. I'm afraid that I can't recommend the K1200. The good news is that the forward closure held up fine. The bad news is the rear closure didn't. The motor worked fine for about half the burn and then let go. Things got interesting after that.

Jim

View attachment 583252View attachment 583253

Jim,

Sorry to see that sir.... That's the same failure mode 1440 that killed my bird.

 

[Art Upton]

Bates grains also made shipping to avoid hazmat fees for easy access of motors with bates grains under 62 grams.

I used a CTI 98mm M moon burning motor for my L3 cert. It had to be shipped at a very high degree of Hazmat and the fee was large; more then an M motor with Bates Grains.

 

[JimJarvis50]

Did your motor retention let go also , or did it hold the huge road flare inside the rocket torching it?

I'm not quite sure what happened. I think the motor, with no thrust ring, tried initially to fly through the rocket. The motor adaptor fell free. Then, the grains relit and did the road flare thing. But there may be more that happened. Still looking at pieces.

Jim

 

[Art Upton]

I'm not quite sure what happened. I think the motor, with no thrust ring, tried initially to fly through the rocket. The motor adaptor fell free. Then, the grains relit and did the road flare thing. But there may be more that happened. Still looking at pieces.

Jim

View attachment 583294

 

[Rocketjunkie]

I used a CTI 98mm M moon burning motor for my L3 cert. It had to be shipped at a very high degree of Hazmat and the fee was large; more then an M motor with Bates Grains.

Aerotech has you glue together the grains so they act as 1 long grain with the moon burners. Same fees as a Bates grain motor the same size.

 

[Rocketjunkie]

That's a good point, but of course suggests that CTI is using the spiral paper liners on motors where they THINK they can get away with it, but really can't.

But then why use the phenolic on 1 grain motors that don't burn any time, don't need the phenolic? Both the I218 and the J430 are White Thunder with a similar burn time making the J430 "hotter".

https://www.thrustcurve.org/motors/...23100000003a7&motors=5f4294d200023100000002da

Aerotech uses paper liners on 1 and 2 grain 54 mm motors, phenolic (and seal disk) on longer motors. You shouldn't need phenolic for short motors unless they burn exceptionally hot.

 

[Art Upton]

Aerotech has you glue together the grains so they act as 1 long grain with the moon burners. Same fees as a Bates grain motor the same size.

Yes I know about those; mine was long before that and I don't really like that idea anymore

 

[Art Upton]

Aerotech uses paper liners on 1 and 2 grain 54 mm motors, phenolic (and seal disk) on longer motors. You shouldn't need phenolic for short motors unless they burn exceptionally hot.

With ALL THIS FIRE GOING ON yea the glue will save you

 

[n3tjm]

I really hope the warranty replaces your aft closure too. Seriously though... I got rid of my 38 and 54mm CTI stuff. Still have my 24 and 29, but availability of what I want has been an issue.

 

[Banzai88]

I really hope the warranty replaces your aft closure too.

Recent issues with replacement 54mm hardware has new tubes not fitting old or NEW closures, and new closures not fitting old or NEW tubes either.......so warranty replacement, at this point, is a crap shoot.

Seriously though... I got rid of my 38 and 54mm CTI stuff.

I'm right behind you on that one.

Still have my 24 and 29, but availability of what I want has been an issue.

And unless that changes soon, we'll all have some pretty expensive wind chime starter kits.

 

[Handeman]

And unless that changes soon, we'll all have some pretty expensive wind chime starter kits.

And I remember when CTI first came out, wind chimes were the suggested use for AT hardware.

 

[pwrwgnwalt]

Thank you, CTI ! (Really; they provided GREAT customer service)

Bought a 54mm Starter Kit over the ‘22 holidays. When I opened the pkg and tried to use it for my L2 Cert in May, found the 3 grain and 6 grain motor tube rear-closure threads were VERY rough and sharp, and the cases were very tight in my rocket’s motor tube. The rear closure would not engage either case more than a turn, and that with great effort. Tried my parts with others’ CTI 54mm tubes and closures, and none of my “new” parts would fit or work with others’ parts.

However, after an email - through the vendor - to CTI and a very quick response from Sandi, within 10 days I had the replacement set (from Canada, at that). After some initial fitment tests, everything appears to be fitting properly. While I don’t have any new motor reloads to test (they are all on backorder), a previously used motor seems to fit more snugly (good) and the motor cases fit my rocket’s motor mount tube a slight bit looser (also good). If the replacement motor tubes they sent are new production and are slightly smaller, I believe CTI may have fixed a few issues.

Thank you CTI !

 

[Seatechnerd83]

Thank you, CTI ! (Really; they provided GREAT customer service)

Bought a 54mm Starter Kit over the ‘22 holidays. When I opened the pkg and tried to use it for my L2 Cert in May, found the 3 grain and 6 grain motor tube rear-closure threads were VERY rough and sharp, and the cases were very tight in my rocket’s motor tube. The rear closure would not engage either case more than a turn, and that with great effort. Tried my parts with others’ CTI 54mm tubes and closures, and none of my “new” parts would fit or work with others’ parts.

However, after an email - through the vendor - to CTI and a very quick response from Sandi, within 10 days I had the replacement set (from Canada, at that). After some initial fitment tests, everything appears to be fitting properly. While I don’t have any new motor reloads to test (they are all on backorder), a previously used motor seems to fit more snugly (good) and the motor cases fit my rocket’s motor mount tube a slight bit looser (also good). If the replacement motor tubes they sent are new production and are slightly smaller, I believe CTI may have fixed a few issues.

Thank you CTI !

Still waiting for CTI to approve my warranty on my p38 4G casing that had a 2 grain skidmark motor in it...

 

[jahall4]

Thank you, CTI ! (Really; they provided GREAT customer service)

Bought a 54mm Starter Kit over the ‘22 holidays. When I opened the pkg and tried to use it for my L2 Cert in May, found the 3 grain and 6 grain motor tube rear-closure threads were VERY rough and sharp, and the cases were very tight in my rocket’s motor tube. The rear closure would not engage either case more than a turn, and that with great effort. Tried my parts with others’ CTI 54mm tubes and closures, and none of my “new” parts would fit or work with others’ parts.

However, after an email - through the vendor - to CTI and a very quick response from Sandi, within 10 days I had the replacement set (from Canada, at that). After some initial fitment tests, everything appears to be fitting properly. While I don’t have any new motor reloads to test (they are all on backorder), a previously used motor seems to fit more snugly (good) and the motor cases fit my rocket’s motor mount tube a slight bit looser (also good). If the replacement motor tubes they sent are new production and are slightly smaller, I believe CTI may have fixed a few issues.

Thank you CTI !

Yep, Sandi is one of the "good people" , a real asset to their organization, if its within her control she will get it "fixed". She was instrumental in CTI's donation of hardware for The Marvin Wright Rocket Project back in 2016. It's unfortunate they can't get their QA issues worked out since the accident. Not test fitting parts in a starter kit is inexcusable, when you know you have quality issues.

 

[berlinetta]

Yep, Sandi is one of the "good people" , a real asset to their organization, if its within her control she will get it "fixed". She was instrumental in CTI's donation of hardware for The Marvin Wright Rocket Project back in 2016. It's unfortunate they can't get their QA issues worked out since the accident. Not test fitting parts in a starter kit is inexcusable, when you know you have quality issues.

This accident, you speak of....when was that? Not sure if you read my previous posts on this thread, but my two J449s have a December 2012 date code. If this accident is well after that date code, I'm 90% comfortable with flying one of them later this year.

 

[mikec]

This accident, you speak of....when was that?

If the CTI fire is what is being referred to, that was in March 2016. https://www.rocketryforum.com/threa...orporated-news-and-well-wishes-thread.133218/

 

[rocket_troy]

Can anyone please tell me what the exit diameter is for the nozzle used in the Cesaroni O3400?

Thanks for any assistance,

TP

 

[Seatechnerd83]

I sent in a warranty request for an H123 skidmark through apogee components in MAY and have yet to receive a WORD from CTI any info on this?

 

[berlinetta]

I spoke to Rick at WildmanCT. He assured me that the J449s were fine. Then again, the nozzle has a huge opening. Looks like the the planned J449 flight will take place in September.