shaft overhang

    Quote from Dan

    Depends, are you hitting stuff? :)


    With two 16mm bands, a 26" and a 28.5", one on your pursuit helper fin tab and one on your secound fin tab, the recoil is too strong for me to tell how bad I am missing lol.

    Diesel, in this case shaft overhang is not your main consideration. I believe you need a gun with more mass, and/or longer bands, or bands with a smoother pull. It's difficult to become accurate with a speargun when you flinch every time you shoot it. Power is of no use when you can't hit the target.

    I use Riffe Godzilla bands...the yellow ones. To be honest, I cannot pull neither of the bands on the last tab, and I am about 6'4" and 265 lol.

    I use to use a single 19mm 32" band, and the gun was underpowered significantly. This is why is use two 16mm bands between 26 and 28 inches. I might just get another 28.5 band and take off the 26.

    Quote from Diesel

    I use to use a single 19mm 32" band, and the gun was underpowered significantly. This is why is use two 16mm bands between 26 and 28 inches. I might just get another 28.5 band and take off the 26.


    Diesel, there is a relationship between band, shaft & gun mass…to balance the outcome for accuracy…just play around with band stretch till you get the least recoil with the shortest bands.


    This is how I would do it.
    - Calculate band length according to the regular 3:1 stretch ratio and stick to 16mm bands….at this -stage, it doesn't matter what brand of rubber you're using.
    - IMPORTANT….for wishbone, go for the Italian style wishbone where you have a knot at the end of each rubber and a separate cord attaching both ends of the bands (if you need help making this knot let me know).
    - Tie the cords with the end knots so that the total length of each wishbone, from rubber end to rubber end is no more than 12cm (assuming you're using 2 Bands)
    - Test your gun in very stable conditions…I use a plastic water bottle in a pool.
    - If you miss after several trials or gun is shooting a bit low, replace the cords and this time increase cord length so that the distance between each rubber end is 14cm…i.e., go in increments of 2cm.
    - Depending on your gun mass and shaft size, at one stage your gun will shoot smoothly.


    The Italian knot makes it very easy to change the cords on location…actually, I would prepare several different cord lengths before testing.


    Good Luck


    Ihab


    This is very useful, thanks Ihab.:thumbsup2:

    Sadot Hernàndez.

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