engine mount kit for Big Daddy??

Discussion in 'Low Power Rocketry (LPR)' started by Bill Gibson, Mar 10, 2019.

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  1. Mar 10, 2019 #1

    Bill Gibson

    Bill Gibson

    Bill Gibson

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    Sandra at at Estes was super cool enough to find me a new body tube for my Big Daddy which Lawn darted a few years ago, but now I realized I need at least a set of centering rings for an engine mount! would anyone have a kit, set or even the template for them I could purchase?? I can make the fins myself.....MANY THANKS!! BILL
     
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  2. Mar 10, 2019 #2

    cwbullet

    cwbullet

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    Last edited: Mar 10, 2019
  3. Mar 10, 2019 #3

    Flyfalcons

    Flyfalcons

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  4. Mar 10, 2019 #4

    rharshberger

    rharshberger

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    +1 for Balsa Machining, Bill also carries the T300-34 which is the same size airframe tube as the Big Daddy and Leviathan.
     
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  5. Mar 10, 2019 #5

    JJSR

    JJSR

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  6. Mar 11, 2019 #6

    GlenP

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    I like the Payload Bay centering ring tool. I would just use 3" as the outer diameter and 24mm as the inner diameter. Print that up on regular copy paper. Find some cardboard in your recycle bin. Glue stick the template onto the cardboard and cut out. You may need to sand down the edges, or cut slightly inside the lines to fit the inner diameter of the 3" O.D. body tube. Likewise cut the inner hole a little beyond the 24mm to get it to fit the OD of the engine mount tube. The Big Daddy fins are TTW, so the cardboard centering rings should have plenty of help holding those D and E engines in place, but if you think it needs to be stronger, glue stick another layer of paper to the other side, or laminate two layers of cardboard with the corrugations at 90-deg angles. You can probably use the cardboard box that Estes used to ship you that body tube. Make the two CRs at the same time, and sand both simultaneously to fit like you would a fin stack, so that the engine mount will be on centerline and parallel to the main body tube. You can get it pretty accurate.
     
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  7. Mar 11, 2019 #7

    rharshberger

    rharshberger

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    Actual ID of the Big Daddy airframe is 2.93" and the OD is 3.0", OD of the BT50 is .976" or the BT50H is .990" OD. Open Rocket will also do Centering ring templates as well, and at the same time allow simulation of the rocket. Hands down Payload Bays fin guide template tool though is my favorite tool from that site.
     
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  8. Mar 12, 2019 #8

    BABAR

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    I use foam board from Walgreens or Walmart pretty regularly for C and D motor mounts.

    I first cut the center holes with a hole drill, 18 mm for a BT-20 and 24 m for Bt-50, than trace a circle around the center hole using the outside body tube. The outer cut is made with an Exacto knife.

    The inner holes are a titch small but with a tiny bit of sanding fit nice and snugly again. Outer diameter again a bit big, but sand down a but for a snug fit.

    Like Glen said, put the rings together to sand them to fit

    I like polyurethane glue for sticking this inside the outer tube, just Use sparingly and wipe up any drips quickly.
     

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