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Low-Drag Spear Gun

It’s not the water, it’s the line.
 
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Handheld spear guns have a reel affixed to the gun and a line tied to the spear. They reel in (manually), but rely entirely on the momentum of the spear to reel out.

I propose using a spring in the reel that is coiled when reeling in, and releases tension when a spear is launched, thus causing the spool to spin in the unraveling direction as the gun is fired.

Shz, Sep 04 2003

This type of spring http://www.hpiracin...lstart/step10-3.jpg
[Shz, Oct 05 2004]

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       The fish probably don't think so.
DeathNinja, Sep 04 2003
  

       [reensure], it’s not a compound bow. It’s so the spear doesn’t have to pull/spin the mechanism by which the line is spooled out upon triggering. I hate to say “Great idea” wasn’t for the correct reason, but...   

       Doesn’t matter ‘cause I got the feelin’ this idea won’t do so well here anyway. In reality there aren’t many people who think the drag on a spear underwater is actually a problem.   

       Thanks for the complementary anno. Now I wonder why there isn’t a compound spear gun bow.   

       [DN], fish don't like me, I’m sure they don't. I shoot at them.
Shz, Sep 05 2003
  

       Once the spear is off the gun, the reel will be spinning at top speed. As the spear slows down, so will the reel. It is drag that slows it, not resistance from the reel.
Freefall, Sep 05 2003
  

       The reel speeds up because as the line is extended the gear ratio changes. This compensates.
Shz, Sep 05 2003
  

       //a way to multiply force on the spool//   

       That is precisely my proposal (and spear guns are a tad more lethal than crossbows BTW).
Shz, Sep 05 2003
  

       You could just have a clutch mechanism and ratchet
FloridaManatee, Sep 05 2003
  

       Just out of curiosity- mu-mu-muahahahaha - If the effective range of a speargun is 7 y or m underwater, how effective is it uh, in say a uh, driveway? And that's uh, without a reel.
thumbwax, Sep 05 2003
  

       Shooting an icicle from either weapon will leave no trace.   

       What is needed is a small charge on the back of the spear which is triggered by the impact of the spearhead. When this charge goes off, it fires a small (blunt) counter spear with line attached back to the spearshooter, who catches it with an apparatus on the gun. Thus spears that miss will not clutter up the water with a lot of unnecessary lines. The line charge will also serve to push the spear deeper into the ..er, target thing.
bungston, Sep 05 2003
  

       [FM] - //You could just have a clutch mechanism and ratchet//   

       It would still have to use the momentum of the spear to spin up the spool.   

       [thumb] - //Just out of curiosity- mu-mu-muahahahaha - If the effective range of a speargun is 7 y or m underwater, how effective is it uh, in say a uh, driveway? And that's uh, without a reel.//   

       My observation is based on using a powerful crossbow in the air. (At roughly 75deg the arrow can be seen landing). Using an un-tethered spear gun at the same angle in air... (Didn’t even seem to arc. - It’s gone).   

       The spear gun I use claims full penetration of sharkskin at 50’, but that’s not an accurate measurement. One can only know from experience.   

       [bungs] - Very cool idea.
Shz, Sep 05 2003
  

       [thumb]'s question is based on using a powerful crossbow on his ex.
angel, Sep 05 2003
  

       No, it's not. A spear gun. I mean, uh, it's not, uh-
thumbwax, Sep 05 2003
  

       Unfortunately you'll get an overspooling issue similar to that faced by overhead/spinning reels in fishing, but much much worse. There would be no reason for the reel to slow down as fast as the spear does - and so the reel would overspool, tangling and pissing you off no end. In fishing reels this is solved by magnetic and inertially applied brakes, etc.   

       I'd suggest you could get around it by using a side-casting type reel (aka australian "alvey" type reel).
Custardguts, Sep 07 2009
  
      
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