Estes E12-6 Cato

[Boosterdude]

What's the story with these motors? My son had a Cato using an E12-6 destroying his Maxi Alpha 3. Has anyone had any success with the E12's! Is there a particular bad date code! This one was dated 08 18 11. I have some good stuff that I want to launch using the E12's, but not until I get a handle on the story.

Not knocking Estes here, this is my first Cato of any Estes motor since I started flying rockets in the 70's. I'll send them an email tomorrow, no doubt they will handle it.

Here's a picture I took yesterday of the Cato.

 

[Boosterdude]

I did fill out the malfunction report on NAR's site.

 

[JimZNJ]

The two I had CATO were from a pack with that same 08 18 11 date code. I gave up on that pack after the first two I tried from it both CATOed on separate occasions. Estes did send me some with a later date code and I didn't have a problem with the one I have flown so far from that pack.

I did notice 08 18 11 show up in several of the CATOs posted in threads here on TRF. It would be a stretch for me to implicate the whole lot, and I certainly don't mean to do that. Perhaps this thread will bring success stories out of the woodwork to help raise our collective confidence in later batches of this same motor. I have several rockets I would love to fly E12's in, but I need to be a little more comfortable with their reliability before I do.

Sorry your son's Maxi Alpha 3 got trashed. That is a nice rocket.

Jim Z

 

[dmorey]

I've had several E12s from 08 18 11 fail. Blows everything out of the casing at ignition. Date code 11 15 11 has worked ok so far.

I even had one of three E9s from 08 18 11 fail. Same result, blows everything out at ignition. Stay away from 08 18 11!

Dave

 

[shreadvector]

We had a one out of three failure rate with the first few packs last year and then I and others flew DOZENS more of all delay times from the same first date code as well as two other date codes and have had ZERO catos since the first launch (and one a week or so later).

Seriously. I personally built several multi stage models to fly a few dozen personally and could not get any to fail!

Speculation is that some may have been left in a hot truck while in transit to one or more retailers but that is pure speculation. We launched several yesterday and they were superb!

 

[Boosterdude]

The two I had CATO were from a pack with that same 08 18 11 date code. I gave up on that pack after the first two I tried from it both CATOed on separate occasions. Estes did send me some with a later date code and I didn't have a problem with the one I have flown so far from that pack.

I did notice 08 18 11 show up in several of the CATOs posted in threads here on TRF. It would be a stretch for me to implicate the whole lot, and I certainly don't mean to do that. Perhaps this thread will bring success stories out of the woodwork to help raise our collective confidence in later batches of this same motor. I have several rockets I would love to fly E12's in, but I need to be a little more comfortable with their reliability before I do.

Sorry your son's Maxi Alpha 3 got trashed. That is a nice rocket.

Jim Z

I'm with you Jim, I want to fly the E12's.

 

[gdjsky01]

I've had E's cato though most recently not an E12, but an E9 which I documented in pictures last Sunday. Twice I've written to Estes since them via their own 'Contact Us' form. No reply. This in stark contrast to the very same form usage a few months ago. I got a good response, a replacement pack, and a rocket to replace the destroyed one.

This time. Shite. Please DO NOT tell me to call Estes. If they want calls, they should REMOVE the form on the web site. I prefer to contact them on my time and terms which is why I use the web form. DONT put up a web form unless you (or your shite outsourced minions) are prepared to answer it.

Yeah I am pissed. Your motors are exploding and you choose to ignore the issue. (witness how many people are complaining about C6-5s or B6-4s... what would that be??? Zero... or very close to it?

 

[CarVac]

You'd think that bad batches wouldn't get through... they claim to test 2% of the motors from every batch in the factory. Not sure how big a batch is, but surely they should be able to notice disturbing trends like that and correct them, right?

 

[chadrog]

Russ took some nice picks of an E12 flight this past Saturday, see if you can guess which ones...
https://www.flickr.com/photos/rocketryruss/sets/72157632448752539/
*my mistake, it was an E9*

 

[cwbullet]

Pretty cool fireball on the flickr photos. https://www.flickr.com/photos/rocketryruss/8352770627/in/set-72157632448752539

 

[Boosterdude]

What is their phone number?

 

[billspad]

You'd think that bad batches wouldn't get through... they claim to test 2% of the motors from every batch in the factory. Not sure how big a batch is, but surely they should be able to notice disturbing trends like that and correct them, right?

Say you've got a batch of 100 motors and a third of them fail. If the two you tested don't happen to be in that third the batch will pass. You could conceivably make a lot of motors before one that you tested fails. Notifying the manufacturer and filling out a MESS form for every motor failure helps everyone because you're "testing" a much bigger part of the batch when you use the motor.

 

[JordanT]

Yes, but their batches are quite a bit larger than 100. In a batch of 10,000, 2% testing means finding a 1% probability flaw 87% of the time, or a 2% probability flaw 98% of the time with at least one of the tested engines.

 

[cerving]

That 08 18 11 batch was hexed. I got ONE motor from that batch it it destroyed a Vagabond... same characteristics as Boosterdude's CATO. Haven't flown a BP MPR motor since.

Then again, ShreadVector flew some 2-stage rockets with E12's from the same batch, no problems. Sounds like he's a luckier guy then the rest of us...

BTW, I sent both NAR and Estes the MESS report, Estes replied back to my email the same day and I had a replacement rocket in a week. I have no bones at all with their customer service.

The two I had CATO were from a pack with that same 08 18 11 date code. I gave up on that pack after the first two I tried from it both CATOed on separate occasions. Estes did send me some with a later date code and I didn't have a problem with the one I have flown so far from that pack.

I did notice 08 18 11 show up in several of the CATOs posted in threads here on TRF. It would be a stretch for me to implicate the whole lot, and I certainly don't mean to do that. Perhaps this thread will bring success stories out of the woodwork to help raise our collective confidence in later batches of this same motor. I have several rockets I would love to fly E12's in, but I need to be a little more comfortable with their reliability before I do.

Sorry your son's Maxi Alpha 3 got trashed. That is a nice rocket.

Jim Z

 

[Boosterdude]

I've already been contacted by Estes about the cato. I've always had great customer service from Estes and it looks like this will be no different. I guess I will be disposing of the remaining two engines in this pack.

 

[Davidtmp]

You'd think that bad batches wouldn't get through... they claim to test 2% of the motors from every batch in the factory. Not sure how big a batch is, but surely they should be able to notice disturbing trends like that and correct them, right?

If the problem wasn't with the motors at the factory, but maybe cycled in a truck, mishandled, etc.....they wouldn't know because none of the motors failed at the factory. I'm not sure if there is a pattern of where these motors are purchased at(ex. Hobby Lobby, LHS, or estes online) or a mix of all. Could be these motors are a bit less resistent to damage from drops for some reason, so when handling the boxes and dropped, the motors get cracks. If most of these were from the same store, and they had a central warehouse that they sent all their stores merchandise, then you could pin point a cause a little better. So many variables could cause this. Many of the failures are from experienced rocketeers, knowing not to store BP motors in garage.

 

[billspad]

Yes, but their batches are quite a bit larger than 100. In a batch of 10,000, 2% testing means finding a 1% probability flaw 87% of the time, or a 2% probability flaw 98% of the time with at least one of the tested engines.

Yes but a batch isn't a batch. The batch code on the motors will tell you what day it was made. Estes has several engine making machines. I have no idea how many were dedicated to the E12's but even if it was just one there are smaller sub batches because the machines don't hold a lot of black powder. And each machine has multiple positions. NFPA 1125 requires that a "random sample of 1 percent of each motor production lot" be static fired. As is typical for the NFPA codes, they don't define lot. Is it 1% of the output of each machine, 1% of the output for a day, 1% of the output for a week or something else? I don't have a hard time believing a good amount of bad motors could slip through.

 

[Derek]

I guess I will be disposing of the remaining two engines in this pack.

I'd ground test them for fun. Too bad estes didn't want them back to dissect and see if they can find a failure mode.

 

[cerving]

I doubt that Estes has the capability to do that. Once you open the case, the compressed BP will simply start spilling out, so they pretty much need to have some kind of MRI or XRay machine to look for imperfections in the motor. The big guys NDT test every solid fuel motor/segment, they can afford it, and they can't afford to have one fail.

I'd ground test them for fun. Too bad estes didn't want them back to dissect and see if they can find a failure mode.

 

[shreadvector]

I doubt that Estes has the capability to do that. Once you open the case, the compressed BP will simply start spilling out, so they pretty much need to have some kind of MRI or XRay machine to look for imperfections in the motor. The big guys NDT test every solid fuel motor/segment, they can afford it, and they can't afford to have one fail.

Black powder will not "simply start spilling out". I conducted motor testing in the late 1970's with a production run of D12 motors. I subjected batches of them to temperature cycling (various ranges) and humidity cycling as well as control groups tested throughout. The motors were provided by Estes to help gather some actual data and theories on motor failure modes and the root cause(s)/mechanism.

When I got the desired 'results' (failures or unusual thrust time curves - they were all tested on the old MIT test stand with the chart recorder producing the curves), I investigated - with Estes' approval - by unrolling the casings to see what the X-rays would not reveal. There were no cracks in the propellant grain. The propellant is a solid hard cylinder - like a piece of chalk. No powder of any kind. The ejection cap could crumble as it was a softer clay and the ejection charge was large granules of black powder, but not "powder".

Failure mode is usually a loss of the mechanical bond between the outside of the propellant grain and the inside of the cardboard casing. Not obvious even when unpeeling since the bond is formed by the propellant expanding withing the casing when loaded and pressed and stretching the casing. WIth temperature cycling, they both expand, but the casing does not retract to it's original tight state. If there is a microscopic gap, the flame front can propagate up the sidewall and cause an overpressure. Often, a small crack would develope around the outer edge of the nozzle/propellant interface. This would actually result in a LOWER peak thrust but if the bond was bad, the flame front could reach the sidewall faster than normal. It usually reaches the sidewall at the moment of peak thrust (max dome shape). With the tiny crack, the peak dome shape is never reached and you get a flattened peak - unless the flame spreads up the sides. Once the flame spreads up the sides, something has to fail. One or more of the following will fail: nozzle (PING off the deflector), propellant grain (roman candle out the top), casing (usually the loudest failure with accompanying roman candle propellant blow through).

Oh well. no more time to type. I've got 3 other things to do right now....

 

[cerving]

And 30 years after the test, they still CATO. Not to knock Estes, but there's no economical way to tell if a BP motor is good or not. I think the probability guys have the right idea, the best you can do is fire a few from each lot and hope statistically that the rest are good. If yours happens to be one of the statistical exceptions, you end up posting here....

 

[Grimracer]

just reading..lol just reading........

Not one.. (How I care for my motors)..lol

Grim

 

[Boosterdude]

I look at it this way, since the late 70's this is my first cato of an Estes motor. So I was most likely due.

 

[cerving]

Yeah, same with me. Estes took good care of me when my E12 CATO'd, so it's all good.

I look at it this way, since the late 70's this is my first cato of an Estes motor. So I was most likely due.

 

[gdjsky01]

Just after staging

​

I have gotten in touch with them...

I contacted Estes twice. Once the day after the E9 failed, and thinking it was the holidays, once again after Jan 1. All via the web site. Zilch. But, I had a contact from the last time I had a no ejection charge issue. On a whim I sent off an email. Blam! One day later I have an answer. Customer service says there were no messages from me in December or Jan. Having spent the past 8 years dealing with writing the back end services for large web sites, I can confirm, things occasionally go wrong and data is lost. I can only surmise perhaps this was the case, tho 10 days apart? As Estes has always been superb it was perplexing I heard nothing back.

So now I am in contact with them and all is well. But only because of prior contact. And that would, were you out there Estes, suggest you really should ask those running the site if there are messages getting lost and to prove they are not.