What Happened!!!!???? Launch Fail

[JeffofSpace]

Hi All,

Was attempting to launch my first mpr...Loc IV. I tried two different Estes G80-7 motors and had the same thing happen both times...short spurt of exhaust, then nothing. Upon inspection, both motor cases cracked...did I do something, or were the motors dropped at the store, or what?????????????????



Thanks for your help!

 

[DizWolf]

Which ignitors and how far in where they?

Hope the rocket didn't get cooked.

 

[JeffofSpace]

Which ignitors and how far in where they?

Hope the rocket didn't get cooked.

Rocket is totally fine. Though the nose cone popped off with the second motor...but the charge didnt go off...so obviously the case cracked and vented?? They were the Estes sonic igniters. First one was only about an inch in. Second was in as far as I could get it.

 

[JeffofSpace]

Here is video

https://www.youtube.com/watch?v=61-Vupsg_DU&sns=em

(From far away, but you can hear the brief ignition then small 'pop')

 

[dave carver]

Rocket is totally fine. Though the nose cone popped off with the second motor...but the charge didnt go off...so obviously the case cracked and vented?? They were the Estes sonic igniters. First one was only about an inch in. Second was in as far as I could get it.

...oh, dear. That was the problem. Composite motors need , nay, require that the igniter go all the way to the delay element. All kinds of bad things can happen when you try to ignite APCP motors at the nozzle.

 

[JeffofSpace]

...oh, dear. That was the problem. Composite motors need , nay, require that the igniter go all the way to the delay element. All kinds of bad things can happen when you try to ignite APCP motors at the nozzle.

But with the second try I put the igniter all the way in. May have slid down a bit I suppose...

Would be useful for a manufacturer to provide a little more information for the novice. Two defunct motors. No flight.

 

[Rocketjunkie]

The problem is there are a certain amount of case failures with the Estes (and Aerotech single use motors). It's a result of the phenolic case, quite strong and heat resistant but brittle. Any damage or manufacturing defect can cause a failure right at ignition. You either have a bad batch or very bad luck to have 2 failures. Failure to put the igniter in all the way results in low thrust and late or no ejection, not a cato. The best solution is to invest in the Aerotech 29/40-120 RMS reload system. Advantages are lower cost per flight, higher reliability (once you learn assembly), and much more variety of motors. Disadvantages are assembly required and an expensive casing that greatly raises the cost of a lost rocket.

 

[Rex R]

please go here https://www.motorcato.org/ and fill out a mess form, then contact Estes costumer support and report the failures. the first one lets NAR track the malfunctions the 2nd lets Estes do so too and probably net you a couple replacement motors.
rex

 

[jadebox]

But with the second try I put the igniter all the way in. May have slid down a bit I suppose...

Would be useful for a manufacturer to provide a little more information for the novice. Two defunct motors. No flight.

The worse that usually results from the igniter not being in the right place is that the motor doesn't ignite. Often, it will take the motor longer to come up to pressure so it "chuffs" a few times before the rocket takes off. It shouldn't result in a motor failure like you experienced.

In your case, either there was a problem with the cases or something caused too much pressure inside the motor.

-- Roger

 

[JeffofSpace]

Thanks, All. Will report to both places. Hopefully another launch window will open in a few weeks!

 

[bobkrech]

Failure to place the igniter all the way into a motor should not cause a cato. The motor may not ignite, may not come up to pressure as quickly as it should, or may cause a longer than normal ejection delay, but it shouild not cause a failed casing. The motor is clearly defective.

As Rex R said, fill out the mess report and notify Estes Customer Service. We at NAR S&T want to know when a motor fals and Estes has good customer services so you are likely to get 2 warranty replacements.

Bob

 

[mikeyd]

In your case, either there was a problem with the cases or something caused too much pressure inside the motor.

-- Roger

I have had this happen, when the nozzle is blocked, either by too much tape, or the motor sitting direct on the blast deflector.

 

[soxfan121]

Don't think it was the problem but to make sure the igniter stays in while sitting on the pad always use either a rubber band (double the rubber band over if loose) or a piece of tape to keep it in, usually with composite motors they come with a rubber band so use that. (I'm not sure if you knew this or not it just sounds like you're new to composite motors)

 

[JeffofSpace]

Don't think it was the problem but to make sure the igniter stays in while sitting on the pad always use either a rubber band (double the rubber band over if loose) or a piece of tape to keep it in, usually with composite motors they come with a rubber band so use that. (I'm not sure if you knew this or not it just sounds like you're new to composite motors)

Yes, new to the motors...but did a fair amount of research. Had the igniters in place with just a wee bit of masking tape. After failure, pulled them out...they were definitely still up in there. Had the blast plate at an angle below the nozzle. The motors never came up to full power. In fact, by the feel of them, they both have a significant amount of propellant still in there, unburnt.

 

[Rex R]

probably better than 99% of the propellant is still there, sudden drops of chamber pressure tends to extinguish AP propellant.
rex

 

[Bazookadale]

Yes, new to the motors...but did a fair amount of research. Had the igniters in place with just a wee bit of masking tape. After failure, pulled them out...they were definitely still up in there. Had the blast plate at an angle below the nozzle. The motors never came up to full power. In fact, by the feel of them, they both have a significant amount of propellant still in there, unburnt.

The wee bit of masking tape - you didn't cover the opening in the nozzle did you? - It must be open to let the gas escape

 

[JeffofSpace]

The wee bit of masking tape - you didn't cover the opening in the nozzle did you? - It must be open to let the gas escape

Partially covered...again, the motors did ignite and exhaust before failure. The blast plate is charred.

 

[dpower]

I've had a few AT SU (some AT branded, some Estes branded) motors fail similarly, sometimes the propellant burns through the side, other times it gets extinguished when the case cracks. The casing material, IMHO, is simply far too brittle. Partially covering the nozzle with masking tape isn't a problem - the RMS motors use a vented plastic plug to hold the igniter in. Estes will replace them.

 

[EeebeeE]

I have an AT 40-120 case, as was mentioned earlier. It is good if you are religious about assembly. You might also consider getting a 3-grain 29mm CTI case and flying the G motors with it. You can get a spacer and fly the 2-grain motors as well. Very easy to load and they are pretty reliable. CTI igniters also are very reliable. Plus you can certify L1 by using that same case for a couple of the H motors that are available for it.

 

[beerandrockets]

I second the CTI 29mm 3-grain case with a spacer. I've flown that instead of the Estes motors a few times. Fun variety of engines and I got my L1 with the H87 reload for it.

 

[Area66]

get the pro 29 starter kit, it come also with the DAT ( delay tool )

https://www.sunwardhobbies.ca/pro29-hardware-starter-kit.htm

 

[DizWolf]

The exciting thing about Estes marketing the pro series II motors was a much wider availability. CTI doesn't exactly carry that trait

 

[TheSamurai]

Sounds like a motor failure but hard to say since the ignitor wasn't all the way in, at least on the first one. I've launched 3 of the Pro Series II motors without the same problem you are having.

 

[TheSamurai]

The exciting thing about Estes marketing the pro series II motors was a much wider availability. CTI doesn't exactly carry that trait

And if you have a Hobby Lobby near you then you can get the motors for under $20 with the 40% off coupon.

 

[Andy Greene]

One out of the 5 PS II G40's I have flown did the same thing- motor failure- Estes made it right.

Andy

 

[neond7]

I've launched at least a hundred SU motors, had one redline fail in the exact same way. Ignitor was all the way in. It lit for a second, went about 1/2 up the rod, then poof.... the motor split and vented, extinguishing the AP.

I contacted Aerotech warranty, after a bit of a delay in communication (the warranty guy was on vacation), they made it right and replaced the SU G77 with a G77 LMS. The LMS is a single-use motor in kit form that is assembled by the user. That was my only time using an LMS motor, but it worked fine!

 

[TheSamurai]

I've launched at least a hundred SU motors, had one redline fail in the exact same way. Ignitor was all the way in. It lit for a second, went about 1/2 up the rod, then poof.... the motor split and vented, extinguishing the AP.

I contacted Aerotech warranty, after a bit of a delay in communication (the warranty guy was on vacation), they made it right and replaced the SU G77 with a G77 LMS. The LMS is a single-use motor in kit form that is assembled by the user. That was my only time using an LMS motor, but it worked fine!

I haven't had the problem yet but then again I am just beginning. But Estes and Aerotech both seem to be pretty generous at fixing issues that customers have. I got an Estes kit that had the wrong size launch lug in the kit and I only called Estes to let them know about it so that they could fix the issue in other kits and they ended up giving me a free kit of my choice. Ended up getting the Super Neon XL for free.

 

[JeffofSpace]

Update...contacted Estes, and they sent out two new motors! Excellent! Here are some photos:
Each of the motors is shown...along with the motor mount...total lightning strike through there. It seems to still be stable...considering whether to replace or not.