What slows down a shaft the most?

    There was a bit of discussion on Hau's enclosed track gun thread about things that slow down a spear shaft. I thought it might be worth its own thread.


    Obviously, there are lots of things that create drag and rob energy from the spear. Here are some that I thought of:


    1. Friction with the track (enclosed, vs. open)
    2. Material of the track (or does a thin film of water support the shaft)
    3. Tapering band ends to make them more hydrodynamic
    4. "Boat tailing" the end of the spear shaft, again to make it more hydrodynamic
    5. Attachment position of the shooting line (trailing as a typical euro shaft, or tied to the shark fin)
    6. Diameter of the shooting line
    7. Design of the flopper (typical, vs. making it more flush into the shaft)
    8. Shark fins vs. pins vs. notches to secure the wishbones
    9. Diameter of the wishbone material.
    10. Connection of the shooting line at the shark fin (for example, a braided line connection vs. crimped mono)


    And any others that you can think of. Love to hear which ones you think might matter, and which are stupid. Especially if you have experimented.

    Quote from Marco

    You forgot to mention woobling, which I think is VERY important.


    Marco, a good word for this is called Spline Cycle, it occurs in archery as well as our sport.
    Cheers, Don

    "Great mother ocean brought forth all life, it is my eternal home'' Don Berry from Blue Water Hunters.


    Spearfishing Store the freediving and spearfishing equipment specialists.

    i think the material of the shooting line also plays some role and I believe the water temerature would have some significant impact too.


    I feel like the use of crimps vs knots would also factor in but much less


    Iwould alos consider the tip. slip tip or fixed. pencil or tri cut. super sharp or rock tip

    i like to spear fish

    I love to see you guys thinking about these factors.I have a very close friend (John Warren) who worked with Bucky Fuller. John and I designed and tested in pools for 25 years. Another great speargun mind is a friend known as Popgun Pete. I have major issues with typing so please don't ban me if I don't contribuite
    allot of data. All my reports were hand written back in the old days. I would like to stimulate your young
    creative minds, this is what your new blood can do for our sport.
    The most important thing I can tell you is buy or build a gun that shoots well, then keep shooting it until
    it is a part of you and your mind. Aim to kill fish or brake the spine, shoot it well and you will develop confidence to make kill shots.With enough water time you may never try to sight down your gun barrel agian.You will see the fish's form. extend your gun and pull the trigger as the shaft later finds is mark.
    Invest in your staking skills and safe bottom time as much as in your gun technology. work to get closer rather than add more power and range.
    I will be happy to try to share a little of what I have learned about guns a little at a time.
    All the best, Don

    "Great mother ocean brought forth all life, it is my eternal home'' Don Berry from Blue Water Hunters.


    Spearfishing Store the freediving and spearfishing equipment specialists.

    Drag force is proportional to frontal area amongst other variables aswell.


    A wobbling shaft can increase it's frontal area many times thereby increasing drag many times.


    I think the effect of this makes all other effects very small or even negligible.


    Stiffening the shaft will improve this but will probably cause spears to snap in big fish.


    I think for slip tip use a very stiff spear will be beneficial.

    Davie Peguero

    Great thread Tin Man. Should read like a things to do list when tweaking a gun for maximum performance. I've always tapered my bands a little, mostly for cosmetic reasons and for a little easier pulling through the band slot, but I never imagined it makes a difference as far as drag.


    I do agree with seaweed in that even all the factors together make a small difference, and with Don that getting close to the fish matters most. We all know though that sometimes no matter what you do the fish will simply not let you get close, and that's where all the tweaking makes a difference.

    Seatec huh. That will raise the price of a spear. Weaken the shaft in a high stress area too.


    I'll just shoot with no flopper and aim for complete pass through/use the whole spear as a slip tip :D Naw, I think the flopper can actually help balance out the spear, and you can make the spear go around corners by bending up the tip :D

    Quote from Dan

    Seatec huh. That will raise the price of a spear. Weaken the shaft in a high stress area too.


    I'll just shoot with no flopper and aim for complete pass through/use the whole spear as a slip tip :D Naw, I think the flopper can actually help balance out the spear, and you can make the spear go around corners by bending up the tip :D


    When you stone the fish it won't matter if you stress it.:D and yes I tune my Tahitian shafts this way.
    Don

    "Great mother ocean brought forth all life, it is my eternal home'' Don Berry from Blue Water Hunters.


    Spearfishing Store the freediving and spearfishing equipment specialists.


    Don,
    You and I have come to the same conclusions and we have never met or dove together. I say " Learn to hunt and the shooting is easy.":toast: Shooting a speargun is like shooting a shotgun - Point and shoot, don't aim and shoot. The only fish I have ever hunted that needs more than two bands is a big tuna and that is because you need more power to shoot through the fish. 30 foot shots are for dreamers and should never be taken.
    Cheers,
    G.R.

    [quote='Tin Man','http://spearfishing.world/forums/index.php?thread/&postID=22512#post22512'] about things that slow down a spear shaft.


    Obviously, there are lots of things that create drag and rob energy from the spear.


    I hesitate to write this, but in response to Tin Mans statement, IMO, spear weight is also a very important factor related to spear speed. IMO, a shorter spear weighs less, is faster and stiffer than a spear of the same diameter that is just 1in longer. That s why I personally shoot the shortest spear possible. Though this opens the discussion of spear speed and spear weight as related to kinetic energy. A lighter weight spear will be faster than a heavier spear, but a lighter spear traveling at the SAME speed of a heavier spear will have LESS kinetic energy. If spear speed is the GOAL, then lighter spears is a major factor. I am not saying that thin,short spears are better for real life spearing, I'm saying that shorter, light weight spears are FASTER.

    Quote from red tide

    Don,
    You and I have come to the same conclusions and we have never met or dove together. I say " Learn to hunt and the shooting is easy.":toast: Shooting a speargun is like shooting a shotgun - Point and shoot, don't aim and shoot. The only fish I have ever hunted that needs more than two bands is a big tuna and that is because you need more power to shoot through the fish. 30 foot shots are for dreamers and should never be taken.
    Cheers,
    G.R.


    Hey G.R. you guys use guns...:D








    Here I am crazy enough to pull the trigger on 6 hot bands and no cup holder:@

    Quote from Dan

    After you're done diving you can paddle home on that gun :D Nice pic!


    Yeah I busted Jay's balls about not having cup holders, It had a metal ET and shot with a big woosh and
    very little recoil. At DEMA it drew a huge crowd at the Rife booth. The gun was bought by a friend in
    Japan, and yes it did kill a fish.;) I had no part in it's build, I was just the test driver.
    Cheers, Don

    "Great mother ocean brought forth all life, it is my eternal home'' Don Berry from Blue Water Hunters.


    Spearfishing Store the freediving and spearfishing equipment specialists.

    Quote from Pucho

    Looks like an old wood surfboard:@, how much shaft overhang on that gun?


    I'll post some more to night.
    Cheers, Don


    1. Jay Riffe with brother
    2.Larry Heinrick gun left. John Warren Tuna gun
    3.Don Paul's Double trouble

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