Estes E12 now available

[Tarasdad]

I have a sneaking suspicion that many of the problems encountered with motors bought from mass market vendors (i.e., chain stores such as HL) come more from the way they are handled by warehouse, transport and shelf stocker personnel than any inherent flaw in design or construction. Anyone who has worked in any of those occupations can tell you that "Fragile" stickers or "Handle with care" on the box mean exactly squat when handling merchandise. It's especially bad when retailers break down bulk packages at the warehouse for redistribution to their stores as it means that many more chances for stock to be mishandled or abused before the customer ever sees it. If merchandise is delivered by commercial carriers like UPS or FedEx...well, we all know those horror stories.

[[POW]Eagle159]

I have a sneaking suspicion that many of the problems encountered with motors bought from mass market vendors (i.e., chain stores such as HL) come more from the way they are handled by warehouse, transport and shelf stocker personnel than any inherent flaw in design or construction. Anyone who has worked in any of those occupations can tell you that "Fragile" stickers or "Handle with care" on the box mean exactly squat when handling merchandise. It's especially bad when retailers break down bulk packages at the warehouse for redistribution to their stores as it means that many more chances for stock to be mishandled or abused before the customer ever sees it. If merchandise is delivered by commercial carriers like UPS or FedEx...well, we all know those horror stories.

Yeah, added on the fact that the engine packaging has no cushions or padding to stop the shock of falling/moving.

[Rocketbuilder]

That certainly seems like a possibility. Also, I'm not sure if they ship them in temperature controlled trucks. I hope so, but I wouldn't be surprised if a lot of motors get temperature cycled that way.

[JimZNJ]

I finally got to fly my first E12 today... well tried to. I've filed a MESS report and dropped a note to Estes. Unfortunately mine blew out both ends right after ignition and roasted the rocket at the same time.

The E12 fills a nice performance niche, so I hope the gremlins can be worked out and the E12 remain a viable part of Estes line-up.

Jim Z

[JPVegh]

Estes has had problems with BP E motors and I don't think it has anything to do with mishandling.

[shreadvector]

As I reported in the past (here and on YORF), I had several packs of E12 motors of all delay times that I got from our local huge hobby store chain. All date code A 08 18 11. (They print it on the motor AND on the back of the motor package now!). We flew a bunch of E12-4 and E12-6 motors at Lucerne Dry lake and 1/3 failed. Flew one more E12-6 a week or two later at our local launch site and it failed.

So, I built 3 special rockets to use up my pack of E12-0 and E12-8 motors and lauched them 2-staged a couple of weeks ago. All worked perfectly and the altitudes were ASTOUNDING. (3 foot long BT-55 rockets with BMS nose cones and really long streamer for recovery).

So, this past Saturday I tried another pack of E12-6 motors in the same 3 rockets single stage. All worked perfectly and altitudes were also really high. They leap off the pad and fly much straighter than an E9 flight because they get up to a higher speed and are less prone to weathercocking.

SO, if anyone else has failures, PLEASE report them to the NAR via M.E.S.S. and alos alert Estes. Estes will replace the rocket and the motors, but they usually send you 2 packs of D12 motors since they can mail them without the HAZMAT cost.

And, since someone will ask, temperature at the time of launch at all locations was between 75 and 85 F.

I finally got to fly my first E12 today... well tried to. I've filed a MESS report and dropped a note to Estes. Unfortunately mine blew out both ends right after ignition and roasted the rocket at the same time.

The E12 fills a nice performance niche, so I hope the gremlins can be worked out and the E12 remain a viable part of Estes line-up.

Jim Z

[AstronMike]

I finally got to fly my first E12 today... well tried to. Unfortunately mine blew out both ends right after ignition and roasted the rocket at the same time.

The E12 fills a nice performance niche, so I hope the gremlins can be worked out and the E12 remain a viable part of Estes line-up.

Jim Z

I flew my first E12 yesterday as well, in a BT80 gliding Bomarc. BOOM!, same deal, blew the nozzle out and fireballed upwards, toasting through the pod, and crumpling the gliders paper NC. Coded 11 15 11. Have *many more* from the same lot too....

[shreadvector]

I know this is an annoying request, but can you confirm that you informed NAR via M.E.S.S. and also informed Estes of the failure?

It helps everyone when you do so, and when you state that you did in this type of posting it helps less experienced readers to realize that they should do the same. Otherwise, the problem can go undetected for a long time. If the manufacturer is informed from as many people as possible, they can do additional testing and determine what the root casue of the failures are and eliminate the failures from future production runs.

Thanks!

I flew my first E12 yesterday as well, in a BT80 gliding Bomarc. BOOM!, same deal, blew the nozzle out and fireballed upwards, toasting through the pod, and crumpling the gliders paper NC. Coded 11 15 11. Have *many more* from the same lot too....

[Donaldsrockets]

Just grabbed my first 2 packs of E12's earlier today. 1 each of E12-4 and E12-6. We'll see what happens.

After just recently launching my new High Flier XL on a D12-5, I'm anxious to see what an E12-6 does in it. Assuming it works correctly.

I'm sorry to hear about these failures though.

[rstaff3]

Well, it appears I jinxed myself by boasting that I've flown a dozen without a problem. Today, a -4 blew both the nozzle and the forward end. MESS submitted and email sent to Estes (I probably should dig up a phone # and call them next week.

[[POW]Eagle159]

I wonder if the engines had more protection in their package, that they wouldnt have as much trouble...

[JimZNJ]

Well, it appears I jinxed myself by boasting that I've flown a dozen without a problem. Today, a -4 blew both the nozzle and the forward end. MESS submitted and email sent to Estes (I probably should dig up a phone # and call them next week.

Sorry you suffered the failure. The pictures of the motor look so strikingly similar to the ones I took last weekend that they made me do a double take. Have you had to contact Estes ever before? I submitted something to them through their website last week and haven't heard a peep. I'm not sure what the best way to reach them is. I suppose I need to pick up the phone this week.

Jim Z

[shreadvector]

Absolutely no effect on this kind of failure. You would have to hit the motor with a hammer very hard to create a propellant crack. This is not a propellant crack failure. It is a mechanical friction bond failure between the propellant and the inside of the casing.

I wonder if the engines had more protection in their package, that they wouldnt have as much trouble...

[rstaff3]

[in response to JimXNJ] I have never contacted them until now. I didn't see a phone number but it might be there(?) Does someone have it memorized?

[[POW]Eagle159]

Absolutely no effect on this kind of failure. You would have to hit the motor with a hammer very hard to create a propellant crack. This is not a propellant crack failure. It is a mechanical friction bond failure between the propellant and the inside of the casing.

Hmm, So why doesnt the D12, E9 or other engines have this problem? I would think that sense its a longer motor, that the bond to casing would be stronger because there is more surface area...

[shreadvector]

The C11, E9 and D12 had a weird period when they switched to the "STRONG LIKE OX" nozzles where they would pop out the nozzle and sit on the pad. They did not blow through.

C11, D12 and E9 and other motors can blow through if temperature cycled or if there is a rare manufacturing defect.

I have noticed that the E12 motors are not swollen and are not as tight in the BT-50 motor mount tubes as many D12 and some E9 motors, so perhaps they are not rammed the same way. I do not know.

Hmm, So why doesnt the D12, E9 or other engines have this problem? I would think that sense its a longer motor, that the bond to casing would be stronger because there is more surface area...

[cerving]

Well, it appears I jinxed myself by boasting that I've flown a dozen without a problem. Today, a -4 blew both the nozzle and the forward end. MESS submitted and email sent to Estes (I probably should dig up a phone # and call them next week.

Wow, it's the same date code that blew up on me, same failure mode too. Did you buy them from SCRA? I think Fred got a bad batch...

[shreadvector]

Wow, it's the same date code that blew up on me, same failure mode too. Did you buy them from SCRA? I think Fred got a bad batch...

I bought mine at Hobby People stores locally. I just got a web/mail order from Hobbylinc and there were two date codes in that batch. One was the same date I already had and the other was a few months later. Have yet to fly any of these.

[AfterBurners]

I just ordered a couple packs for my 4x24 clustered rocket...it should scream!!

[C-57D]

I just ordered a couple packs for my 4x24 clustered rocket...it should scream!!

Just remember, the chances of a CATO go up substantially with multiple motors.

With 4 motors, a 5% chance of a single motor CATO, means the probability of a failure is ~18.6%.... a 15% CATO rate becomes almost a 50/50 chance of failure.

[Mick2b]

I have seen two E12's ignited and they both blew up the Rocket. I saw NJ JImZ and then another one at METRA today. I urged the gentleman to report it. Saw a D12 fireball as well on the pad today, had not seen that before.. Gonna hold off on these until I see a few successful flights

[plastic_gorilla]

twas my poor golden pancake on said fated d12... got about 40 feet into the air... something is up with the nozzles. the motor retention held the nozzle in but when it landed and the nozzle was pushed up about 1/4". Just reported to estes a couple of hours ago and will report to NAR tomorrow. never seen anything like it. it just popped of the pad about 30 to 50 ft then blew out the motor mount. The lot number being A081011 saw that number earlier in the thread - perhaps something changed in the manufacuter process in that time. I have been building and flying estes for a long time - hope they get this worked out.

[dpower]

Flew my first E12 today, -0 in a spool, and it worked great! Sample size 1, success 100%. Date code 11-15-11. How's that for statistical significance

[chadrog]

Flew my first E12 today, -0 in a spool, and it worked great! Sample size 1, success 100%. Date code 11-15-11. How's that for statistical significance

I do wish I could post video clips without uploading them to youtube, it was a nice flight.

[cvause]

I saw a great rocket destroyed two weeks ago from an E12. I just made a large order and I'm sticking with AT E18 reloads for that power range. This is too scary and the E18 reloads are selling for $15 per three pack if you have the case it's the same price as the E12s

[bobkrech]

I personally know of (8) E12 motor failures with the 8 18 11 manufacturing date.

Bob

[Green Jello]

So what's the general consensus here? I'm about to need some of these E12-0 for the first time, but I'm kinda scared of them. Should they still be avoided? Is that August 2011 timeframe the only ones to avoid?

[MarkH]

I'm batting a thousand. Launched an E12-8 today, date code 4-2-12, no problems. I also have a pack of the 11-15-11 date code. My Rock-It screamed "NOOO!", but I pushed the button anyway.

[billspad]

I'm batting a thousand. Launched an E12-8 today, date code 4-2-12, no problems. I also have a pack of the 11-15-11 date code. My Rock-It screamed "NOOO!", but I pushed the button anyway.

What's the letter in front of the date code on yours?

[MarkH]

What's the letter in front of the date code on yours?

Both packs have the letter A. What does the letter indicate?