Twice as long - twice as good?

Discussion in 'General Slingshot Discussions' started by JoergS, Sep 30, 2012.

  1. JoergS

    JoergS Administrator

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    OK, I am talking about slingshot crossbows... nothing more, nothing less <img src="http://illiweb.com/fa/i/smiles/icon_smile.gif" alt="Smile" longdesc="2"><br><br>One of my most powerful slingshot crossbows is the winch operated hand cannon. It can handle much stronger rubber than any conventional slingshot. But it has an active draw length of only about 75 cm!<br><br>The speed (and energy) of a 25 mm steel ball fired from the weapon is an impressive 45 m/s, about 67 Joules of energy. But I extended the "barrel" to twice the original length, giving the weapon a total acceleration length of 165 cm. <br><br>This leads to a speed of 69 m/s, increasing the energy of the 25mm steel ball to about 162 Joules - 2,4 times more!<br><br>As a bonus, a new two shot bullpup crossbow is shown. It fires two full size arrows, either at the same time or in consecutive order. Outfitted with a surplus G36 scope, it is really accurate and powerful enough to penetrate a car.<br><br> I decided to present a prototype in this week's bonus.<br><br><embed pluginspage="http://www.macromedia.com/go/getflashplayer" src="http://www.youtube.com/v/7TSrTF4Smak" width="425" height="350" type="application/x-shockwave-flash" wmode="transparent" quality="high" scale="exactfit"></embed>
     
  2. Jan84

    Jan84 New Member

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    WOW awesome! <img src="http://illiweb.com/fa/i/smiles/icon_biggrin.png" alt="Very Happy" longdesc="1"><br><br>I love the arrowshooter! very cool <img src="http://illiweb.com/fa/i/smiles/icon_smile.gif" alt="Smile" longdesc="2">
     

  3. Ryan Wigglesworth

    Ryan Wigglesworth Senior Member

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    <div>wow. now i want the arrowshooter so badly lol. so cool Joerg . so cool <img src="http://illiweb.com/fa/i/smiles/icon_biggrin.png" alt="Very Happy" longdesc="1"><img src="http://illiweb.com/fa/i/smiles/icon_exclaim.gif" alt="Exclamation" longdesc="16">
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    <br><a href="http://voiceofquran.info/mp3_files/german_quran_mp3/001.mp3" target="_blank" rel="nofollow">http://voiceofquran.info/mp3_files/german_quran_mp3/001.mp3</a><br>my website! <a href="http://wigglesworthswoodwork.webs.com/" target="_blank" rel="nofollow">http://wigglesworthswoodwork.webs.com/</a><br>For your spiritual well being ( more important than anything ) <a href="http://muttaqun.com/" target="_blank" rel="nofollow">http://muttaqun.com/</a>
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  4. Firepower

    Firepower New Member

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    Nice arrow shooter Jörg! <img src="http://illiweb.com/fa/i/smiles/icon_smile.gif" alt="Smile" longdesc="2"> that's pretty awesome tech!
     
  5. ameevis

    ameevis New Member

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    Nice! i really want to make a winch cannon like that, you should make some plans for it!
     
  6. linuxmail

    linuxmail New Member

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    Joerg, with the standard cannon, you cranked it up and shot. With the extra-long cannon, you had it pre-cranked, and then talked a bit before shooting it.<br><br>Wouldn't the delay have reduced the efficiency and power of the extra-long cannon? So wouldn't the actual speed and power, be even greater than you demonstrated?<br><br>Brian
     
  7. pasquale

    pasquale Member

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  8. JoergS

    JoergS Administrator

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    <table width="90%" cellspacing="1" cellpadding="0" border="0" align="center">
    <tr><td><span class="genmed"><b>linuxmail wrote:</b></span></td></tr>
    <tr><td class="quote">
    <br>Wouldn't the delay have reduced the efficiency and power of the extra-long cannon? So wouldn't the actual speed and power, be even greater than you demonstrated?</td></tr>
    </table>
    <span class="postbody"><br><br>Brian, the delay will make a difference, but it is small - because the draw weight is very high, about 60 kg. That is about five times more than my most powerful handhelds. <br><br>That is what you do when you make rubber based crossbows - knowing that the cooling will lead to about 20% draw force loss until the bands reach room temperature, you just use 20% more rubber. The winch allows that.</span>
     
  9. Bert the Welder

    Bert the Welder New Member

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    That's is excellent Joerg! Fingers crossed for getting the show. <br><br>As to peoples frequent requests for plans, what if you were to do really nice plans with descriptions, full measurements and photos of the whole building process. You could sell the plans. They do this on another forum I follow, atomiczombie.com. <br>I've got a feeling, however, the money for the return of doing full plans isn't something you'd feel worth it. Just had to throw it out there though <img src="http://illiweb.com/fa/i/smiles/icon_smile.gif" alt="Smile" longdesc="2">
     
  10. onnod

    onnod Im from Holland, isnt that weird?

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    <table width="90%" cellspacing="1" cellpadding="0" border="0" align="center">
    <tr><td><span class="genmed"><b>Bert the Welder wrote:</b></span></td></tr>
    <tr><td class="quote">As to peoples frequent requests for plans, what if you were to do really nice plans with descriptions, full measurements and photos of the whole building process. You could sell the plans. They do this on another forum I follow, atomiczombie.com. <br>I've got a feeling, however, the money for the return of doing full plans isn't something you'd feel worth it. Just had to throw it out there though <img src="http://illiweb.com/fa/i/smiles/icon_smile.gif" alt="Smile" longdesc="2">
    </td></tr>
    </table>
    <span class="postbody"><br>i know a guy on utube who does that as wel, his name is matthias wandel, but if you are putting so much effort in it they will have to pay a fortune for a set of plans and if you are skilled enough to make something you will probably be skilled enough to figure some stuff out</span>
     
  11. Bert the Welder

    Bert the Welder New Member

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    <table width="90%" cellspacing="1" cellpadding="0" border="0" align="center">
    <tr><td><span class="genmed"><b>onnod wrote:</b></span></td></tr>
    <tr><td class="quote">i know a guy on utube who does that as wel, his name is matthias wandel, but if you are putting so much effort in it they will have to pay a fortune for a set of plans and if you are skilled enough to make something you will probably be skilled enough to figure some stuff out</td></tr>
    </table>
    <span class="postbody"><br><br>Very true. Though skill and imagination can have quite a gap sometimes. This is where sock-puppets come in handy. <br><br>Is that "Matthias" the one that builds Python recumbent's?!?! If so, do you know him personally or just know his video's?</span>
     
  12. JoergS

    JoergS Administrator

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    The idea is valid, but I really don't want to start selling stuff, even if it would be plans only. It would spoil the true character of my hobby, which is entertainment. <br><br>If the TV guys pay me for beeing an entertainer, that is OK. But starting a business is something that I have done before, and running it is often a pain in the butt. No thanks.<br><br>
     
  13. onnod

    onnod Im from Holland, isnt that weird?

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    no not the python recumbent guy, and i only know his vids, he builds stuff like his own bandsaw, router jig, airgun, and the exploding sawdust bottle target shown here somewhere...