buttefly vs full butterfly speed comparison | The Slingshot Community Forum

buttefly vs full butterfly speed comparison

Discussion in 'General Slingshot Talk' started by Arturo Borquez, Jan 18, 2021.

By Arturo Borquez on Jan 18, 2021 at 4:02 PM
  1. Arturo Borquez

    Arturo Borquez Veteran Member

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    I don have a crony, extracting audio with audacity (better than airgun phone app), bands are 20mm x 15mm taper, TBS clone, ammo 7/16" steel

    butterfly delay 0.155 secs yields 80 m/s average
    bfspeed.jpg

    full butterfly delay 0.141 secs yields 90 m/s average
    fbfspeed.jpg

    velocity near the forks should be higher.
    a net 12.5% increase and 26.5% more energy at 10 mts
    Arturo
     
    Last edited: Jan 18, 2021
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Discussion in 'General Slingshot Talk' started by Arturo Borquez, Jan 18, 2021.

    1. KawKan

      KawKan Veteran Member

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      Good job, Arturo!
      Great demonstration of changing band performance by extending the draw.
      I have played with Audacity also.
      I wouldn't bet that the speeds would be the same over a chronometer, but I expect the percentage variation would be just what audacity showed.
       
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    2. Palmettoflyer

      Palmettoflyer Veteran Member

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      Very interesting! I might see if I can do this with my chrony this week. Winds have been crazy for the weekend, but if things calm down a bit I can try it. I have my Samurai Conus banded with BSB 0.5mm and would like to measure the speeds with it. Just bought some BSB 0.45 and need to benchmark the 0.5 speeds before I change to the thinner band.

      Thank you Arturo for sharing your Audacity tests. I've used that program too, but for sound editing purposes. Never tried to use it as an event recorder.
       
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    3. Bone

      Bone Veteran Member Staff Member Moderator Admin

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      Dead Rabbit!
       
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    4. Arturo Borquez

      Arturo Borquez Veteran Member

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      Hey Monroe, maybe you can share some the audio records with the corresponding chrony result at 10 mts, I have some clues on where the ball leaves the pouch at the audio track, paired audios with chrony speeds would help me a lot
       
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    5. Palmettoflyer

      Palmettoflyer Veteran Member

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      Arturo, it would be a pleasure to do that. It will be Thursday or Friday before I have a chance to do anymore shooting. Next 2 days are busy family days for a couple of home projects.

      Do you use anything special to record the sound or just a cell phone voice recorder? Then import the file into Audacity to analyze it? Once I get to it, I'll send you the audio file and Chrony results that match.
       
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    6. Arturo Borquez

      Arturo Borquez Veteran Member

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      Thank you very much Monroe !!! The arrangement needed is the following:
      1) Distance to target 10 mts.
      2) Cardboard target, better if it is hard.
      3) The cellphone by your side, (same 10 mts from the target).
      4) Distance from the forks to the microphone.

      The sound file (with audacity) should look like the ones I've posted.
       
    7. Searcher_47

      Searcher_47 Veteran Member

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      Interesting. Now if I could just get over the fear of taking my ear off......
       
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