Wiggly nozzle on K480

The Rocketry Forum

Help Support The Rocketry Forum:

Buckeye

Well-Known Member
TRF Supporter
Joined
Sep 6, 2009
Messages
2,790
Reaction score
573
I assembled an AT K480 in the 54/2560 case. The aft closure is fully seated, but not enough to compress the aft o-ring and nozzle. The nozzle wiggles around. I don't recall this ever happening on any other reload I assembled. Should I be worried?

Seems like an aft insulator would take up the slack, but this reload does include one.

video clip:

 

rfjustin

Well-Known Member
Joined
Jan 21, 2009
Messages
3,041
Reaction score
1,834
Location
Franklin, WI
Forward closure also fully seated? Assuming so, yes I would be concerned. Liner is likely too short...
 

Theory

Well-Known Member
Joined
Nov 30, 2018
Messages
1,003
Reaction score
772
Likewise, I have never seen this.

If fired like that I bet a gap would open internally that would cause a gas leak resulting in a serious issue.

recommend contacting Karl at Aerotech
 

crossfire

Lifetime Supporter
TRF Lifetime Supporter
Joined
Jan 16, 2011
Messages
4,889
Reaction score
674
Is the seal disk in?
 

crossfire

Lifetime Supporter
TRF Lifetime Supporter
Joined
Jan 16, 2011
Messages
4,889
Reaction score
674
Post video on AT FB page Gary will probably get back to you.
 

Buckeye

Well-Known Member
TRF Supporter
Joined
Sep 6, 2009
Messages
2,790
Reaction score
573
Forward closure also fully seated? Assuming so, yes I would be concerned. Liner is likely too short...
Yes. Lucklily, I have another reload (K375NW) for this case. I will compare the liner lengths.
 

mtnmanak

TRA & NAR L2
TRF Supporter
Joined
May 5, 2020
Messages
946
Reaction score
947
Location
METRA & MDRA
I had a similar issue a few weeks ago with an Aerotech K456DM. It was just loose. I asked a bunch of people at the field and no one was really sure. Most people had not seen that exact issue before, so we didn't think to check the liner length. The general consensus was "just crank it down as hard as you can and it should be good". Unfortunately, "go now" fever won over and I flew it. Here are the results:


I was able to recover the electronics (the ebay ejected clear) and the nosecone, but the 72" Fruity Chute burned up, the booster was toast and the heat was so intense it melted the adapter ring on the Aeropack 54mm-75mm adapter and it completely warped the Aerotech case (both ends were flared out).

We ended up having 3 CATOs that day - all on Aerotech 54mm. I have no clue if the other people who experienced a CATO had the same issue, but I do know I am now going to go back and check the liner lengths on all my motors I have on hand.

Does anyone know what the lengths of the liners are supposed to be for each case so I can check them? Without a reference chart, it will be difficult to know if any of them are wrong unless I can figure out a known-good one and go from there.

That was an expensive CATO.
 

0011001100

A Person
Joined
Jun 28, 2017
Messages
745
Reaction score
267
Location
Northern VA
@AeroTech , Can we get your confirmation that all the liner lengths listed on this site are accurate?

RCS is Aerotech. These are the individual parts and you can buy everything you need from here to make your own motors using their hardware, including propellant.
 

Nytrunner

Pop lugs, not drugs
TRF Supporter
Joined
Oct 15, 2016
Messages
8,001
Reaction score
3,719
Location
Huntsville AL
That being said, the RCS components could be victim of the same manuf-slip that resulted in 2 reloads having short liners/loose nozzles
 

tfish

Well-Known Member
Joined
Dec 8, 2009
Messages
2,769
Reaction score
875
That being said, the RCS components could be victim of the same manuf-slip that resulted in 2 reloads having short liners/loose nozzles
Knowing Gary and Karl,,,I'm willing to bet that all the liners in stock have been re-measured and they probably already have been in contact with vendors that might have been affected.

Tony
 

AeroTech

Lifetime Supporter
TRF Lifetime Supporter
Joined
Dec 17, 2009
Messages
557
Reaction score
1,046
I had a similar issue a few weeks ago with an Aerotech K456DM. It was just loose. I asked a bunch of people at the field and no one was really sure. Most people had not seen that exact issue before, so we didn't think to check the liner length. The general consensus was "just crank it down as hard as you can and it should be good". Unfortunately, "go now" fever won over and I flew it. Here are the results:


I was able to recover the electronics (the ebay ejected clear) and the nosecone, but the 72" Fruity Chute burned up, the booster was toast and the heat was so intense it melted the adapter ring on the Aeropack 54mm-75mm adapter and it completely warped the Aerotech case (both ends were flared out).

We ended up having 3 CATOs that day - all on Aerotech 54mm. I have no clue if the other people who experienced a CATO had the same issue, but I do know I am now going to go back and check the liner lengths on all my motors I have on hand.

Does anyone know what the lengths of the liners are supposed to be for each case so I can check them? Without a reference chart, it will be difficult to know if any of them are wrong unless I can figure out a known-good one and go from there.

That was an expensive CATO.
What was the lot number of your motor?
 

crossfire

Lifetime Supporter
TRF Lifetime Supporter
Joined
Jan 16, 2011
Messages
4,889
Reaction score
674
I had a similar issue a few weeks ago with an Aerotech K456DM. It was just loose. I asked a bunch of people at the field and no one was really sure. Most people had not seen that exact issue before, so we didn't think to check the liner length. The general consensus was "just crank it down as hard as you can and it should be good". Unfortunately, "go now" fever won over and I flew it. Here are the results:


I was able to recover the electronics (the ebay ejected clear) and the nosecone, but the 72" Fruity Chute burned up, the booster was toast and the heat was so intense it melted the adapter ring on the Aeropack 54mm-75mm adapter and it completely warped the Aerotech case (both ends were flared out).

We ended up having 3 CATOs that day - all on Aerotech 54mm. I have no clue if the other people who experienced a CATO had the same issue, but I do know I am now going to go back and check the liner lengths on all my motors I have on hand.

Does anyone know what the lengths of the liners are supposed to be for each case so I can check them? Without a reference chart, it will be difficult to know if any of them are wrong unless I can figure out a known-good one and go from there.

That was an expensive CATO.
My question is if you felt it was not right why did you fly it? Sometimes you just need to scrub it. You lost a lot with going ahead and flying it.
 

AeroTech

Lifetime Supporter
TRF Lifetime Supporter
Joined
Dec 17, 2009
Messages
557
Reaction score
1,046
For this particular liner, the K480 mentioned by Buckeye was the only one with that lot number. Here are others that could be affected:

K375
01062102
01062103
01202103
01202105

K700
011420

K1275
01192105

K1103
01252103

If you have any of these reloads with the corresponding lot numbers, do not use the reload and email Karl immediately at [email protected].

We are also contacting our dealers with this information. Thank you for your patience and cooperation.
 
Last edited:

mtnmanak

TRA & NAR L2
TRF Supporter
Joined
May 5, 2020
Messages
946
Reaction score
947
Location
METRA & MDRA
@AeroTech What is the tolerance on the liners? I checked all my liners and I found one that is 1.5mm short. Is that within tolerance?

It is a K1103X lot # 01062104
 
Last edited:
Top