Birdie clone insta-build

Discussion in 'Low Power Rocketry (LPR)' started by caveduck, Jul 5, 2019.

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  1. Jul 5, 2019 #1

    caveduck

    caveduck

    caveduck

    semi old rocketeer

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    This is going to be a single-post build thread. Maybe two if the forum software won't take all 6 photos at one go.

    We got a tube of badminton birdies at Big 5 yesterday to replenish our supply...of course I liberated one for nefarious purposes. I actually had an ulterior motive - to check out this stuff for possible use in building a Saturn V model:
    upload_2019-7-5_5-33-41.png

    To make the Birdie I just looked for a few suitable parts and started building. Of course the original Estes Astron Birdie used a BT-20 tube for the old "shorty" 18mm motors, but I wanted a flyable one so I modernized to BT-5. Parts layout:
    upload_2019-7-5_5-37-40.png

    There are only 4 parts: the birdie itself, a 1.5" piece of BT-5 or other 13mm tubing (I used vintage BT-5), a 1.75" piece of 1/8" paper launch lug, and a BT 5-60 paper adapter ring.

    I fiddled around with stuff for a minute to see how the launch lug could pass through the webbing of the birdie, quickly realizing that I'd need to notch the foam head to let the launch lug sit closer to the centerline. I did the notching with the trusty Dremel diamond cutter, which worked great on the dense foam. Just be sure to line up the notch between two of the longitudinal ribs in the skirt of the birdie. The notch in the foam is about 0.1" deep - a bit more than half the diameter of the lug. Keep trial-fitting the parts until the lug sits parallel to the motor tube and the skirt doesn't distort.
    upload_2019-7-5_5-45-2.png

    Then cut a notch for the lug inward from the outside of the ring to a depth of 5/16" (8mm). Here are the parts after notching and ready for assembly.

    upload_2019-7-5_5-48-21.png

    There are only two steps to assembly. First, mix up a small batch of the plastic welder epoxy and put some on the back face of the head to resist ejection blast and hold the tube. Assemble with the tube, launch lug and ring, put a very small amount of plastic welder along the lug/foam slot, and put the rest of the plastic welder around the seam where the outer edge of the ring meets the skirt.

    upload_2019-7-5_5-50-44.png

    I didn't worry much about neatness, this is a speed build after all! The plastic welder acts like regular 5-minute epoxy but by its odor apparently contains some plastic solvent. After it sets, mix a small batch of regular 5-minute epoxy and glue the tube/ring and launch lug/ring joints. That's it - completed Birdie!

    upload_2019-7-5_5-54-2.png

    Total build time about 20 minutes. It kind of looks like a Dalek.
     
    Mugs914 likes this.
  2. Jul 5, 2019 #2

    Funkworks

    Funkworks

    Funkworks

    Well-Known Member

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    Did it fly yet?
     
  3. Jul 5, 2019 #3

    caveduck

    caveduck

    caveduck

    semi old rocketeer

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    No, flying season is over here in SD until mid August. It might go with me to NARAM.
     
  4. Jul 9, 2019 #4

    jqavins

    jqavins

    jqavins

    Joseph Avins TRF Supporter

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    So, wait, you had an ulterior nefarious plan?
     

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