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Discussion in 'Mid Power Rocketry (MPR)' started by Todd00000, Jan 4, 2020.
Estes Big Daddy using an E12-6. Blew up at launch. Do you think Estes will reimburse me?
Please file a MESS report > motorcato.org
Contact Estes customer service and send the pictures. Do you have a picture of the defective motor, too? They may help you out.
I need to go back and find it.
I'm not sure you need it. Before you spend time searching, get in touch with Estes.
I was told by Estes to send a photo of my E12-6 CATO in November after I sent photos of the rocket by itself.
Yes they will. They have excellent service and go above and beyond what most vendors do! I would call them or email them the pictures.
Good gravy! It bent the deflector like that? That impressive.
It would be nice to have the serial number of the motor.
Do you have any other motors from the same pack? Check the date code against the list of known bad E12 motors.
Before we get started:
1) Welcome to the forums!
2) Aw!!! Bummer man! Nobody likes to see a rocket that someone cared about get damaged/destroyed. Sorry that it happened to you.
A couple of things that can cause CATOs of BP motors are thermal cycling, and poor handling.
If the motors somehow are exposed to hot temperatures (say during transportation (hot semi trailer or car)), or in a shed during summer), then get cold (say on a cold launch day, or in the car), the BP could have expanded due to the heat, then contracted from the cold, cracking the propellant, or allowing it to pull away slightly from the inside of the case. A drop can also crack the propellant.
Those cracks increase the surface area that is burning, causing it to burn faster, and with more pressure than the casing can handle. Thus, you get a CATO.
Some people keep their motors close to their body, until the last possible moment, when launching on cold days. This is done to keep them warm, and reduce the chance of damaging the grain.
Also, if you can repair the rocket, or decide to replace it with another Big Daddy, you might want to consider modifying the nosecone. Big Daddy rockets seem to have a higher than normal incidence of lawn darts. My theory is that the lightweight, high drag design of the fin can, combined with the slope on that nosecone's shoulder, causes drag separation of the nosecone during the coasting stage of the flight. If the slope is exposed enough, when the ejection charge fires off, the gasses are vented out the side, instead of pressurizing the recovery bay, causing the rocket to turn turtle at apogee without a chute being deployed.
A drop will not crack the propellant. It would need to be hit with a hammer to crack the propellant grain. Proven scientifically in R & D reports.
Cold does not crack the propellant. Again, this is just scientifically false.
The main cause of black powder motor catos is a gap forming between the side of the grain and the inside of the cardboard casing.
A hairline crack can form between the nozzle and propellant grain, but this results in LOWER peak thrust and internal pressure. It does allow the flame front to reach the casing wall faster, so if the bond is compromised the cato will occur sooner than the normal time.
Estes made good and sent me two new kits.
Glad you got the kits replaced. Estes has absolutely phenomenal customer service.
Not to sound paranoid, but I've seen too many Estes E motor catos to trust them at all. That's not to say other sizes don't cato, (had a 13mm A10-3T cato in a mini X-wing fighter once), but those Es just seem more prone to it. If I may suggest, consider switching to Aerotech composite motors for anything bigger than a D motor. Their E15-7W is fantastic for any rocket meant to take Estes D and E motors, but add that throaty roar and thicker smoke of the bigger motors.
Since you can't control how hot the motors got during storage or transport, I only fly them in warmer weather
Is that a picture of lighting a fuse with a lighter?
I remember my very first E motor launch too. It didn't blow up but it did go horizontal and crash. That's when I found out the hard way that an Estes Maxi V-2 and an E9 were a very bad match for each other.
He's holding up his bent blast plate by the little Center thing
I had good look with the E9 motors--I liked the long burn--but Estes seems to have stopped making them. I switched to an E12, had a cato. Luckily, no damage I could see. Estes sent me a new pack of E12s. First flight, cato, and this time I wasn't so lucky--I had to rebuild the rocket. Another flier had 2 catos, then static tested the third--yet another cato:
Now I'm skittish of the E12s...
GNA - What were the date codes of your E12 CATOs?
D 19 06 19
I filed MESS reports and posted in the Cato thread.
The other flier’s were the same, though another member at the launch had E12s that started with a B, and had flawless performance.
FWIW: D 19 06 19 has been on the list since 07/07/19
Agreed. I am very wary of E12's. Estes is very good about some sort of compensation, however, it can take a lot of effort to repair a model and can be a real setback if the model is a favorite.
Flip a coin to positivly know if your E12's gonna blow.
Bought before then. Pics are from last summer. Snow on the ground now...
My V2 is post 27.
It is still my kids' favorite launch.
Last weekend a few of us got together for our annual mid-winter Rocket Boy weekend. One of the guys flew an Estes E engine, not sure which one. It catoed. Another friend of mine took these photos.
Flew 105 rockets at the last launch.
5 were E12 and 1 was E9. All worked perfectly.
Date codes or perfect motors:
E9-4 061702 (they did not write down the letter - if there was one)
E12-4 A071417, H191219,unknown (they did not write it down...)
E12-6 B180718, H190919
Separate names with a comma.