SwitchbladeXP Upgrade [J&H Aerospace]

Discussion in 'Rocket Boosted Gliders' started by Crawf56, Apr 7, 2019.

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  1. Apr 7, 2019 #1

    Crawf56

    Crawf56

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  2. Apr 7, 2019 #2

    Crawf56

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    The SwitchbladeXP is no longer available from J&H. It was superseded by the Swingshot C.

    So, let's start by figuring out where the CG is on the SwitchbladeXP. I put an empty motor casing in, along with a battery.

    I found the CG to be roughly 35mm from the leading edge of the wing, down at the root/swing point. (Roughly where the red triangles are.)

    m_IMG_0013small.jpg
     
  3. Apr 7, 2019 #3

    Crawf56

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    And, while taking the motor mount off, I cracked the balsa.

    I cut the small piece of balsa off the motor mount, and glued it back on the glider.

    m_IMG_0014small.jpg


    m_IMG_0015small.jpg
     
  4. Apr 7, 2019 #4

    Rktman

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    Eric Noguchi

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    Curious to see how it handles with the extra grams of motor weight. You'll definitely get more altitude and launch stability.
     
  5. Apr 10, 2019 #5

    Crawf56

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    Yeah, hoping to get more altitude.

    Attaching the 18mm motor mount, with the larger nose.

    m_IMG_0019small.jpg
     
  6. Apr 10, 2019 #6

    Crawf56

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    Back of the motor mount is about 7/8 inch from the leading edge of the wing.

    m_IMG_0021small.jpg
     
  7. Apr 13, 2019 #7

    Crawf56

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    Also replaced the Kevlar line that 'trips' the wings into flight position. Appears to be roughly 100 pound chord.

    m_IMG_0023small.jpg
     
  8. Apr 13, 2019 #8

    Crawf56

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    I had to trim around the guide tubes, but the string seems to be moving freely.

    m_IMG_0025small.jpg
     
  9. Apr 13, 2019 #9

    Rktman

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    Eric Noguchi

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    That thicker thread should definitely have a longer working life, good choice.
     
  10. Apr 13, 2019 #10

    Crawf56

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    Thanks. It was an idea from J&H. The thinner Kevlar thread was starting to fray.
     
  11. Apr 13, 2019 #11

    Crawf56

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    Let's burn a B4-4 for the casing, to get the Center of Gravity right! :p

    m_IMG_0026small.jpg


    m_IMG_0030small.jpg
     
  12. Apr 13, 2019 #12

    Crawf56

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    After playing with components, and a motor casing and battery, I came up with a Glide Weight of 44 grams.

    This compares to a glide weight of 35 grams with the smaller motor.

    m_IMG_0033small.jpg
     
  13. Apr 13, 2019 #13

    Crawf56

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    Ok, this looks really ugly, but hopefully will be functional....o_O

    I taped & tied the Receiver under the servos. This gave me weight aft of the CG to compensate for the bigger motor [18mm]. Also did some tape and kevlar string.

    The Receiver has power, causing the red glow under the Servo.

    m_IMG_0036small.jpg
     
  14. Apr 14, 2019 #14

    Crawf56

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    And the battery up front.

    m_IMG_0034small.jpg
     
  15. May 13, 2019 #15

    Crawf56

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    Had a successful launch and glide today! Used a B6-2.

    m_IMG_0065small.jpg

    m_IMG_0064small.jpg
     
  16. May 13, 2019 #16

    Crawf56

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    I was able to get higher altitude, and a much better glide experience. With greater weight (25% heavier), the glide rate was a little worse; but performed good.
     
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  17. May 14, 2019 #17

    Rktman

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    Eric Noguchi

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    Congrats! Sounds like that larger motor really made a difference. Glad to hear the glider can handle the extra power and didn't rekit itself.
     

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