Need help figuring out why my 1:100 Saturn V launch was a catastrophic failure

Discussion in 'Low Power Rocketry (LPR)' started by Darren Nolan, Feb 10, 2020.

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  1. Feb 10, 2020 #1

    Darren Nolan

    Darren Nolan

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    Hello friends,
    I recently built a gorgeous Estes 1/100 Saturn V (posted a picture of it a few weeks ago). Yesterday I finally launched it and it was a terrible failure and the rocket is destroyed. I had an E12 in it and the rocket seemed under powered. The exhaust has from the rocket motor completely burned and melted the lower 3” of the fuselage.
    The instructions from Estes say to insert the engine mount 3-3/8” inside the fuselage which I can’t understand why (CG maybe?). Being recessed up there is why my rocket died...as I said the heat inside the fuselage from the engine down was incinerated.
    Please look at the photos I’ve pasted links to.
    Any help greatly appreciated!
    https://photos.google.com/share/AF1...?key=amhOUVZnV08wb0RXaU9MaHZfYnhxNzNibVk4dC1n
     
    Last edited: Feb 10, 2020
  2. Feb 10, 2020 #2

    Greg Furtman

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    Where are the links?
     
  3. Feb 10, 2020 #3

    CalebJ

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  4. Feb 10, 2020 #4

    SecondRow

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    Did the rocket leave the pad? How far up off the launch pad did you set the rocket? The instructions say it needs to be 8” off the pad. Otherwise you risk Bernoulli lock with the motor mount recessed in the rocket. I have not seen the pics, but this would be my guess.
     
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  5. Feb 10, 2020 #5

    Darren Nolan

    Darren Nolan

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    Links refuse to show for some reason. Let me try another way
     
  6. Feb 10, 2020 #6

    Darren Nolan

    Darren Nolan

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  7. Feb 10, 2020 #7

    CalebJ

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    Do you have any pictures from before the launch showing how everything was set up? The suggestion of Bernoulli lock sure seems to fit.
     
  8. Feb 10, 2020 #8

    Darren Nolan

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    OK I'm pretty embarrassed to say that I missed the 8" off the pad part. It was right up against it. It probably formed a vacuum somewhere and wasn't able to get moving.
     
  9. Feb 10, 2020 #9

    SecondRow

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    Right up against the pad - definitely Bernoulli lock. The vacuum forms between the rocket and the pad. The motor is not strong enough to get it off the pad once that happens. So the insides just get cooked.

    That instruction is very easy to miss. I’ve seen others post the same problem. I wish Estes would make that step a little more clear (maybe in big letters).

    Estes has really good customer service. Give them a call or email - let them know what happened. They may try to make it up to you.
     
  10. Feb 10, 2020 #10

    CalebJ

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    For what it's worth, I don't actually see the 8" suggestion in the instructions.

    https://estesrockets.com/wp-content/uploads/Instructions/002157_APOLLO_11_SATURN_V.pdf


    Edit - it's in the 1969 kit instructions, but not the 2157 as far as I can tell. Seems like a massive oversight.
     
    Last edited: Feb 10, 2020
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  11. Feb 10, 2020 #11

    SecondRow

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    They updated the 2157 instructions. Those are the really old 30th anniversary 2157 instructions. I have a 2157 bought within the last few years with the instructions that look more like the 1969 ones. The 8” standoff is in there, but real easy to miss.
     
  12. Feb 10, 2020 #12

    samb

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  13. Feb 10, 2020 #13

    Darren Nolan

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    Argh I just saw them on the new instructions here https://estesrockets.com/wp-content/uploads/Instructions/001969_SATURN_V.pdf

    What a fail! I did email Estes though. I told them everything including my oversight to see if they recommend anything. I’ll update once they reply.
     
  14. Feb 10, 2020 #14

    CalebJ

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    Glad to hear they've updated the 2157. I didn't have a paper copy handy and just pulled up the PDF from the site.
     
  15. Feb 11, 2020 #15

    JumpJet

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    All I can say is the rocket modeling public should be thankful I'm not in charge of customer service. I am asked for my opinions on many warranty claims sent in. If it was up to me Estes would be sending out a lot less stuff. I see a lot of these clams posted online either before or after the fact. In many case the letters sent in are written in a way that if I was in charge I would simply through them in the trash. You guys have no idea of the stuff that is sent in. Such things as wanting a replacement rocket for the one that landed in a tree, complaining the rocket was damage because the engine ejection charge malfunctioned but then state that the nose cone and parachute did in fact come out but the chute didn't open,to the same person repeatedly sending in claims for missing parts on just about every model they purchase; No one can be that unlucky. Then you have those that complain about something and the first thing they state is that they are a Level 2 or Level 3 flier and therefore they know what they are doing, but in reality the issue is something simple like not inserting the engine into the model all the way so the clear plastic fin unit is lose for flight. Sorry to have written this but this is my ten years worth of getting it off my chest where it comes to customer service complaints. All I can say is sometimes, just sometimes, the person complaining should in fact accept some of the blame.
     
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  16. Feb 11, 2020 #16

    CalebJ

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    What about this particular thread triggered that response? The OP seems willing to accept responsibility.
     
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  17. Feb 11, 2020 #17

    ThreeJsDad

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    Seriously ! The OP said it was his mistake and wrote to Estes hoping they would take pity on him. He made no claim the rocket or motor was defective.

    I realize that most Americans have been trained in the Wally World mentality that it is always the vendors or manufacturers fault but in this case the OP admitted he messed up.
     
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  18. Feb 11, 2020 #18

    samb

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    Maybe the Chief Designer could have picked his spot better. I read it as a general vent from an insider. It does seem to go against the grain of current customer service practice. But I don’t disagree with the spirit of the message.
    RTFM ?
     
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  19. Feb 11, 2020 #19

    ThreeJsDad

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    I know more about customer service than I would like to and JumpJet is absolutely correct. On more than one occasion I have wished I had not had to deal with some people or some situations. I think maybe it was the placement of the post.
     
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  20. Feb 11, 2020 #20

    neil_w

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    When excess pressure builds up in a system, at some point it will need to be released. It is not always predictable where or when. :)

    Estes customer service policies are generally very generous. That is a calculated business decision to keep customers coming back to buy more, rather than get frustrated with what can be a challenging hobby. Some will take advantage of the situation. It is not unexpected for an engineer to view this all with some frustration. As an engineer I can relate. :)

    In any case, it *is* connected to the case at hand. OP made a catastrophic mistake, albeit one that is unfortunately rather easy to make. Contacted Estes customer service. What is the expected outcome here? I don't know. If I drop my iPhone and break the screen, I'm not gonna expect Apple to do anything for me. But again, Estes is known to be very generous and seemingly really wants to avoid customers having a bad taste in their mouth about about their products, even if it is not (completely) Estes' fault. I bet they'll do *something*, although maybe short of sending a new kit. We shall see!
     
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  21. Feb 11, 2020 #21

    CalebJ

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    Honestly, 'something' in this case seems like just making the launch procedure documentation a little more clear because it's relatively unusual.
     
  22. Feb 12, 2020 #22

    nosecone

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    There is a video on YouTube by the same username of the flight
     
  23. Feb 12, 2020 #23

    lakeroadster

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  24. Feb 12, 2020 #24

    SDramstad

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    Did you put the top of the motor mount 3-3/8ths in or the bottom of it that far in?
     
  25. Feb 12, 2020 #25

    SDramstad

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    Okay, just looked at your instruction sheet. Weird........
     
  26. Feb 12, 2020 #26

    ThirstyBarbarian

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    That's too bad. If Estes doesn't send you a replacement, which seem like a long shot, and you want another one, I have the 50th anniversary one (model #1969) for a reasonable price. Send me a PM if interested. I would recommend a higher thrust motor, like an Aerotech E20.
     
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  27. Feb 12, 2020 #27

    rcktnut

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    Those models definitely need bigger motors. I would also modify the display with nozzles and mount the mmt farther to the rear of the bt.
     
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  28. Feb 12, 2020 #28

    SpaceX76

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    you need to fly them on bigger motors next time you could put some tin foil around the inner walls as a heat shield
     
  29. Feb 12, 2020 #29

    samb

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    That one second after ignition with the rocket sitting on the blast deflector did the damage. A bigger motor with the rocket sitting on the blast deflector will do more damage. Gotta raise it to avoid Bernoulli lock.
     
  30. Feb 12, 2020 #30

    3stoogesrocketry

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    Or the manufacture of the kit needs to "idiot proof" their design so this stops happening.....


    This is in no way a bash at the OP
     

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