Estes E9-P problems

[mswiggins]

I helped with a school demo today and was going to launch an Applewhite 24mm Scimitar on an E9-P.
The motor blew out the nozzle and only got about 6' in the air. I got another E9-P and it did the same thing.

We had an E9-P do something similar in a demo about 1 year ago.

I am going to email Estes about this.

Has anyone had something similar happen? Is this just common to the E9-P?

Thanks

Marty

[sandman]

Take some pictures of the results you may be asked to send them to Estes.

http://www.estesrockets.com/contactus.php

Be sure to fill out this form

http://www.nar.org/NARmessform.html

[mswiggins]

I will take pics and email Estes. I have done so in the past.

We were lucky. Something similar happened before and it burned up the Applewhite 24mm Stealth.

[Mikus]

Not just the plugged, but E motors in general I think.

I blew the nozzle on an Estes E9-6 myself about 2 years ago. It just sat on the pad spewing burning gloop onto the blast deflector. To this day, no other motor has done that but I've read several reports of the same thing and they all seem to be E's.


I helped with a school demo today and was going to launch an Applewhite 24mm Scimitar on an E9-P.
The motor blew out the nozzle and only got about 6' in the air. I got another E9-P and it did the same thing.

We had an E9-P do something similar in a demo about 1 year ago.

I am going to email Estes about this.

Has anyone had something similar happen? Is this just common to the E9-P?

Thanks

Marty

[mswiggins]

The problem is that the E9-P is OOP... I love that motor in the Applewhite 24mm stuff.

[shreadvector]

The nozzle popping out with the propellant staying firmly in place (and burning with zero thrust but lots of flame) is not super common, but it has been happening to D12 and E9 motors. I first heard about it on this forum (or the original version) just before NARAM 48 and then it happened to me at NARAM 48 and I saw a few others. I have since seen about 2 or 3 more at our club launches on D12 and E9 motors.

Reporting the problems helps to identify the root cause and leads to improvments in quality. Thanks.

[jeff_in_AZ]

I had an E9-6 do the same thing, but later decided it was due
to (my) operator error. I used a D12 igniter plug (white) rather
than an E9 igniter plug (black, smaller in diameter, same as C11).
I think I probably cracked the nozzle, which led to the CATO.
Live and learn. It sure rearranged our Blue Ninja fin can!

jeff

[shreadvector]

I had an E9-6 do the same thing, but later decided it was due
to (my) operator error. I used a D12 igniter plug (white) rather
than an E9 igniter plug (black, smaller in diameter, same as C11).
I think I probably cracked the nozzle, which led to the CATO.
Live and learn. It sure rearranged our Blue Ninja fin can!

jeff

I doubt you caused a problem with the larger plug. The most it could do is chip the inside of the nozzle if you really forced it in, but the plug will still pop right out upon ignition. The nozzle failure where it pops out of the casing is a failure of the nozzle to casing bond and it occurs right at ignition, well before the flame front has reached the inner casing walll.

[jeff_in_AZ]

Thanks Fred, good information. I guess we'll never know for
sure but, based on your input, I will forgive myself for that one.

jeff :D

[Gus]

Marty,

I've launched a lot of E9-Ps in Art's Scimitar. Even the seasoned veterans always get a kick out of it.

In fact, when the E9-P went OOP I bought up a ton of them to use in my Scimitars.

I've not had a blowout problem.

Any chance your motors may have gotten temperature cycled during storage?

[mswiggins]

"Any chance your motors may have gotten temperature cycled during storage?"

Not really...

I also bought up several packs of the motors when they went OOP.
If they have been temperature cycled, they are the only motors that have been affected. I have not had any other motors to fail.

I have launched everything for A3-4 up to E9s and the E9-P is the only one that has failed on me.

[Indiana]

That's what the "P" is for, the Pinging sound it makes when the nozzel bounces off the blast shield.



Just kidding, but you're not the first one to have have an E9's nozzle come out.

[Obi-Wan]

I saw the same guy CATO two E9 a while back. Both times he put a white D-12 type plug in the nozzle instead of the correct black plug for the smaller D9 nozzle. It was a shame I didn't catch it until after the second launch. Both nozzles were found with the white plug and igniter wires.

[shreadvector]

I saw the same guy CATO two E9 a while back. Both times he put a white D-12 type plug in the nozzle instead of the correct black plug for the smaller D9 nozzle. It was a shame I didn't catch it until after the second launch. Both nozzles were found with the white plug and igniter wires.

Absolutely nothing to do with the plug. In the "old days" (and today) we would install bare nichrome wire igniters and CRAM a ball of wadding into the nozzle and RAM-ROD it in with a metal poker. These paper plugs are much, much tighter than any soft plastic plug. All plugs will pop right out when ther is any pressure build up. The nozzles that pop out with a "PING" do so at the instant of ignition and there is virtually no pressure build up. They seem to have little or no mechanical bond to the inside of the casing.

[jeff_in_AZ]

Let me make sure I understand. "Obi-wan" is saying that they found
the nozzles afterward and they still had the white igniter plug
in, along with the igniter. Fred, you are saying that the real problem
was with the adhesive bond between the nozzle and the casing and, even if
Obi-wan's friend had used the correct black igniter plug, the nozzle
would have still popped out. Is that right?

If the problem is a bad bond from the nozzle to the casing, then what to do?
I hate to risk a nice rocket trying to figure out if this is a good E9 motor.
In my case, the other 2 motors in the pack were ok, so it's not always a
bad 3 pack. Would it be useful to add a fillet of epoxy at the nozzle end
of an E9 motor just in case?

jeff

[dwmzmm]

Not just the plugged, but E motors in general I think.

I blew the nozzle on an Estes E9-6 myself about 2 years ago. It just sat on the pad spewing burning gloop onto the blast deflector. To this day, no other motor has done that but I've read several reports of the same thing and they all seem to be E's.

Mikus,

The same thing happened to my FSI Maverick in one of our very first launches
at Needville last year. The E9-6 just sat on the pad for what seem like eternity belching flame and smoke (and lots of it) before finally burning out.
I think I have a few pics of that incident in my files. BTW, I did report it to
Estes and they offered a free replacement. My Maverick sustained very minimal damage.....:shock:

[shreadvector]

There is no "adhesive" bond, it is a simple mechanical bond formed by pressing it in under very high pressure.

There is no way to detect this defect.

I have not heard a proven scientific explanation for exactly why this failure occurs (i.e. is it created during manufacturing - inadequate pressure, impurities on the inner casing wall, etc? - or is it induced during shipping/handling - is the new nozzle material more sensitive to temperature cycling than the propellant grain?).

I have seen very few D12 and E9 motors fail compared to the number of motors that worked flawlessly. I will continue to fly them.


Let me make sure I understand. "Obi-wan" is saying that they found
the nozzles afterward and they still had the white igniter plug
in, along with the igniter. Fred, you are saying that the real problem
was with the adhesive bond between the nozzle and the casing and, even if
Obi-wan's friend had used the correct black igniter plug, the nozzle
would have still popped out. Is that right?

If the problem is a bad bond from the nozzle to the casing, then what to do?
I hate to risk a nice rocket trying to figure out if this is a good E9 motor.
In my case, the other 2 motors in the pack were ok, so it's not always a
bad 3 pack. Would it be useful to add a fillet of epoxy at the nozzle end
of an E9 motor just in case?

jeff

[new2hpr]

I had it happen to a 3x cluster of E9-6's. All three popped the nozzles and it sat burning on the pad. Not pretty, but it still counts on my 100% success rate with cluster ignitions!:cool:

Ken

[mswiggins]

I had it happen to a 3x cluster of E9-6's. All three popped the nozzles and it sat burning on the pad. Not pretty, but it still counts on my 100% success rate with cluster ignitions!:cool:

Ken

I bet they had the same date code.
The last two that failed on me were of the same code.