Your thoughts on my cluster mount for the Estes Saturn V #1969

Discussion in 'Mid Power Rocketry (MPR)' started by Euclid, May 17, 2019 at 11:03 PM.

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  1. May 17, 2019 at 11:03 PM #1

    Euclid

    Euclid

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    Hi, I decided I wanted the option of installing 5 motors (1x 24mm and 4x 18mm) in my Estes Saturn V #1969, so I built this:

    IMG_0585.jpg

    The centering rings are 2.3 mm and 1.5 mm basswood I cut and drilled, and the red electrical tape is just my cheap way of attaching the motor hooks. I alternately used both epoxy and wood glue for no particular reason.

    My concern now is how deep should this be recessed in the BT-101 tube. Too deep and I suppose the outer motors could char the tube.

    Any other thoughts you might have before I glue this in are welcome, thanks.
     
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  2. May 17, 2019 at 11:32 PM #2

    lakeroadster

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    Run a line at 45 degrees from the outer motor c/l to the bottom edge of the main body tube. Don't go any deeper than that.

    If it were me I'd make the centering ring about a 1/4" inside the body tube, then make some nozzles for display that look like the F1 nozzles.

    How are you planning to fire all those off at the same time? E-matches?
     
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  3. May 17, 2019 at 11:37 PM #3

    David Schwantz

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    I built mine with one central 29mm mmt. Will she still fly straight if 1 or 2 outers do not lite? With it being recessed so deep in body, will you be able to get at the engine hooks. I have an aeropack retainer and that is even hard for my fat hand. Other than that I think it is a great idea! Will the motors all have ejection charges?
     
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  4. May 18, 2019 at 12:16 AM #4

    afadeev

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    Pure genius!
    It's astounding how adding those extra tubes firmed up the entire MMT assembly, even using the Estes cardboard centering rings.

    I've covered the interior of the exposed airframe (aft of the motor retainers) with a few layers of thin CA, for extra protection.
    Everything will get installed as per the instructions, and some sidewall charring will be expected. If it gets too aggressive, I will re-coat the interior of the exposed airframe with a thin layer of epoxy.

    Saturn V 5-motor mount-small.jpg

    a
     
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  5. May 18, 2019 at 12:45 AM #5

    Euclid

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    I have some "MJG Firewire Initiator" ignitors. They worked perfectly for ground testing a dual-deployment system (on another rocket), and I'm about to test them with a 2-cluster rocket (before I do with this 5-cluster).
     
    Last edited: May 18, 2019 at 12:54 AM
  6. May 18, 2019 at 12:52 AM #6

    Euclid

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    It won't be recessed very far. I'll just make sure lakeroadster's idea looks good and go along those lines. I haven't decided how many ejection charges there should be. I understand if 5 go off at the same time, it might be hard on the frame, so I still have to think about that. First launch will likely be on a single E12 or E30 (depending on final weight).
     
  7. May 18, 2019 at 2:02 AM #7

    David Schwantz

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  8. May 18, 2019 at 8:11 PM #8

    Euclid

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    Very interesting products. It brings to mind auto body aluminum foil tape, which would be much cheaper. Compromises, compromises.

    https://3m.citrination.com/pif/000114?locale=en-US
     
  9. May 18, 2019 at 9:10 PM #9

    BABAR

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    Looks great.
    Loaded with expected motors, how is CG affected?
     
  10. May 18, 2019 at 9:19 PM #10

    David Schwantz

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    I also have used the tape a LOT! I does not protect as well.
     

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  11. May 18, 2019 at 11:59 PM #11

    Euclid

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    I don't know yet. I'm still working on the exterior. I just put on most decals today. I accidentally threw away the service module thrusters while they were drying up, so I ordered some more from Estes. Still a few weeks before I'm done, but I'll still be ready for July 16th.

    Does anyone have the location for the center of pressure for this kit? I understand this value should be the same for all units, no matter who builds it or what's inside. It's just based on the silhouette.
     
  12. May 19, 2019 at 12:01 AM #12

    Euclid

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    Also, I still have access to the service module, so if I need to add weight, I can still add plenty in there. The CM is already filled with all 4 pieces of clay.
     
  13. May 19, 2019 at 12:16 AM #13

    Euclid

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    Yeah well. If it survives 2 or 3 flights, I'll be happy!
     

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