Which shaft?

    9/32 or 5/16 7

    1. 9/32 (3) 43%
    2. 5/16 (4) 57%

    Background:


    Ive finally compiled all the parts necessary to start my first build. Its going to be a 55" rear handle plus, euro style gun with a poured epoxy enclosed track. stock dimensions right now are 1.8" wide and 1.6 thick. The main use for this gun will be reef hunting but I will b attaching a reel and I would love to take this gun offshore for dolphin some time. I plan to power the gun with between 2 and 3 5/8" power bands. 2 for reef fishing and adding a 3rd for offshore or spooky reef fish.


    Question:


    Im stuck between using a 9/32" and 5/16" shaft for this gun. I currently shoot a riffe 100X with the 7.1 mm (9/32) and have had no problems with it at all. However having a discussion through one of Tinman's threads about shaft diameter, Im torn between the shaft that Im comfortable with (9/32) and that has less recoil and the shaft that has superior range and punch for larger fish but also higher recoil.


    Thanks guys

    The problem with the 7.5 mm is finding a ball cutter to cut the track. 9/32 and 5/16 are much more common sizes that I can use without breaking the bank.


    thanks for the input though. 7.5 mm definitely gives me an in-between size that I hadn't considered

    funny i have nearly the same problem..


    hy there,
    i decided to build my gun up with the ball cuter from neptonics5/16 which gives me a clearance of 0,5 which is abit less then the ball cuter 11/32 that Wood Guy used in his gun building thread.
    ithink it will also fit a 8mm dia. shaft..
    and it will fit for the 9/32 shaft as well..


    I will use the neptonics reef mech which allows both shafts
    BUT :overkill:


    i don t know which shaft will work better..damn
    so at the moment it looks like i m gonna buy both sizes and have a try.
    Somewhere i read that because of the higher mass a5/16 shaft is able to work with longer distance but tends therefor more to bend if shootn on rocks...
    Does one here think this is true?


    creets..

    sometimes i m asking if the freaks know that they are in the majority..

    5/16 with 3 5/8 and a little mass in the launch platform, better accuracy on long shots, deeper penetration into
    head shots on Pargo, grouper and AJ. The 5/16's is less likely to be bent when trying to keep a fish from holing up too deep or too far back in the crevice. The 9/32 can have a little more speed at close range but loses
    it fast after 10 feet with just 2 5/8's bands at 300% elongation. A 5/16 also is more like a Porsche Caynne than a Ferrari...when pulling the resistance of cable (wire rope) or 400lb mono it will not be slowed down as much on long shots pulling a load.


    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.

    Thanks Don,
    the cayenne will be the right one for me:D
    you have taken my last doubts!

    sometimes i m asking if the freaks know that they are in the majority..

    Quote from blankwalker

    Thanks Don,
    the cayenne will be the right one for me:D
    you have taken my last doubts!


    When I started spearfishing over 30 years ago 3/8 for American guns was the norm and 5/16 the light weight.
    I use 9/32 on all of my guns from time to time but my stack of bent shafts is much larger in that diameter.;)
    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.

    The ball cutter that I use for a 9/32" and 5/16" shaft (Tin Man's design) has a 3/16" neck. I'm not positive, but I think the Neptonics ball cutter has a 1/4" neck. No problem for a 5/16" shaft, but a little close for a 9/32" shaft (1/32" difference between shaft diam. and neck size). Tin Man specified a 3/16" neck to leave a little more material above the shaft, so the 9/32" shaft couldn't fall out if the gun was inverted. I haven't used one of Josh's ball cutters for a 9/32" shaft so I can't say whether the 1/4" neck would be a problem with the 9/32" shaft or not. Maybe some of you all have used the ball cutter for a 9/32 shaft and could comment. Josh offers a great ball cutter at a reasonable price for a custom cutter, and I'm not knocking his products. I just wanted to point out the difference in neck size, since the two cutters were brought up.


    Quote from seaweed

    7.5mm, I think 5/16 is to big.


    Agreed! Love it! Cut the track for a 5/16ths shaft. Not enough slop to be concerned with and you will still have the option of going to a 5/16ths. I have also shot a 9/32 shaft out of a 5/16th enclosed track gun with no issues.


    Just make sure the gun is ballasted for a 5/16ths shaft. Shooting a lighter shaft never seems to be an issue. It's when you try and shoot a heavier shaft for which the gun was designed, that issues arise.

    Getting a shaft to fit properly in the track is one of the most aggravating parts of building a gun for me. Not because it is hard, but because I always want it to be "just right". The problem, of course, is that "just right" only applies under one specific combination of circumstances. Throw in a smaller shaft, or some sand, or another coat of epoxy, or an imperfect shaft, or whatever, and the fit changes. I guess what I have learned is that this is one of those places where a speargun builder has to set aside any precision tendencies and be OK with a little slop. So far as I can tell, shooting my 9/32" shaft works fine in my 5/16" gun. Sure, it rattles around uncomfortably when it is unloaded and sitting on the bench. But load a band or two and it's fine.


    So if it's me, I would cut the track for a 5/16" shaft, and feel perfectly comfortable shooting a 9/32" or anything in between. Just be sure not to cut it too deep, so that the shark tabs (or pins, or whatever) stick up high enough.


    An for what it's worth, Bob White at SFS Carbide can modify my cutter drawings to make you any size you want, if you have something specific in mind.

    Edited once, last by Guest ().

    Quote from Tin Man

    Getting a shaft to fit properly in the track is one of the most aggravating parts of building a gun for me. Nto because it is hard, but because I always want it to be "just right". The problem, of course, is that "just right" only applies under one specific combination of circumstances. Throw in a smaller shaft, or some sand, or another coat of epoxy, or an imperfect shaft, or whatever, and the fit changes. I guess what I have learned is that this is one of those places where a speargun builder has to set aside any precision tendencies and be OK with a little slop. So far as I can tell, shooting my 9/32" shaft works fine in my 5/16" gun. Sure, it rattles around uncomfortably when it is unloaded and sitting on the bench. But load a band or two and it's fine.


    So if it's me, I would cut the track for a 5/16" shaft, and feel perfectly comfortable shooting a 9/32" or anything in between. Just be sure not to cut it too deep, so that the shark tabs (or pins, or whatever) stick up high enough.


    An for what it's worth, Bob White at SFS Carbide can modify my cutter drawings to make you any size you want, if you have something specific in mind.


    i actually think that when it comes to tracks looser(within reason) is better . a perfect fit can cause problems . when it comes to this part of the build think ak47 not m16 . it has to work with grit and sand in it and work every time
    phil

    :D


    OK butter bei die fische..


    to create a AK47 gun with a porsche Cayenne shaft i extract from urs both stats it s better to have a clearance of 0,8 rather than 0,52.
    keeping an eye on a small shank as Wood Guy mentioned....alright:cool2:
    no problem!


    my blanks are nearly ready to get it on.
    cant wait for it...

    sometimes i m asking if the freaks know that they are in the majority..

    Quote from Don Paul

    5/16 with 3 5/8 and a little mass in the launch platform, better accuracy on long shots, deeper penetration into
    head shots on Pargo, grouper and AJ. The 5/16's is less likely to be bent when trying to keep a fish from holing up too deep or too far back in the crevice. The 9/32 can have a little more speed at close range but loses
    it fast after 10 feet with just 2 5/8's bands at 300% elongation. A 5/16 also is more like a Porsche Caynne than a Ferrari...when pulling the resistance of cable (wire rope) or 400lb mono it will not be slowed down as much on long shots pulling a load.


    Cheers, Don


    This.

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