Tapered shafts

[portinfer]

I was idly wondering if there is any advantage to using a tapered shaft - maybe with more thickness at the sharp end.

Would this have better dynamics over a longer range ?

Just an idle thought but I guess someone with a handle on ballistics can put me out of my misery (not literally please).

Ed

 

[spaghetti]

what does tapered mean in english? is it "very sharp-pointed" as my dictionary say, or what else?
By now, I may say that any "step" between sharpend-end and flopper is certainly a loss of penetration power, but in my language misery i'm not sure that this helps your question. Embarassed.

 

[portinfer]

Ciao Spaghett - no what I meant was if you change the thickness of the shaft over the entire length.

So at the trigger end it is 6mm and then it thickens towards the sharp end to something like 8mm... Just a weird idea...

 

[spaghetti]

you mean slim in the tail and progressively fat to the point? Like a mortar grenade? If so, advantage could be a greater shock power to knock out fishes like groupers in cave or even bass (bass has tender meat: you often loose them if they react after being badly hit, but if you stone them with a heavy shaft reaction is feeble).
Misadvantage could be in ballistic issues: thicker end could make shafts sink in the beyond part. Also, slimmer tail (the part in contact with the wishbone) could badly affect recoil, cause a slimmer mass in that section is less capable to absorb power from slings. Not a scientific answer, just common sense as it seems to me. There must be a reason if shafts like that are not on the market...

 

[socalspearo]

Interesting idea! Intuitively I don't think that having a thicker shaft near the tip would be good for a few reasons.
1: Shaft whip is caused when the bands try to accelerate the rear end of the shaft faster than the tip can be accelerated. The result is that the shaft bends rather than trnsferring all of the power from the bands through the axis of the shaft to the tip. The result is an innacurate shot. Adding weight near the tip and taking weight away from the back would compound this problem by making the tip more difficult to accelerate and making the rest of the shaft less resistant to bending (smaller 2nd moment of area...for the engineers out there )
2: Same thing spaghetti said, heavy tip will cause the shaft to drop quickly.

However, the opposite might be a good idea. Having a shaft with a larger diameter at the base than at the tip. Or possibly having a shaft that got thicker towards the middle then tapered down toward the ends.

My suspicion is that while these changes might slightly improve shaft performance, it would not be worth the additional cost to make them.

Interesting idea though.

 

[Mako]

I agree that tapered on both ends would be the cat's meow. And not worth the additional cost.

It's kinda like the roller gun concept. Good in theory but adding a 2nd band works even better for less money.

 

[Huan]

I agree that tapered on both ends would be the cat's meow. And not worth the additional cost.

It's kinda like the roller gun concept. Good in theory but adding a 2nd band works even better for less money.

The advantage with rollers is that a very powerful gun can be made with a very short length.
You can't do that with a double rubber gun.
interesting idea re: the teardrop shaft, but I wouldn't like to machine it, or pay for it.

 

[portinfer]

Like I say : I was daydreaming... but in practice how about buying a fatter shaft - ie an 8mm shaft and then machining it down ... could you just rub it down by hand ?! ... Probably not
Ed

 

[Huan]

Anything is possible but I wouldn't like to try rubbing it down by hand....
Especially not hardened spearshaft material.
but hey! what the hell go ahead and buy a devoto shaft and try out your theory, if it is any good I'll buy one off you