Archers Paradox

[maxwell9699]

Having watched a lot of slowmotion filming of arrow flight. How far does an arrow have to travel before it assumes level flight by that I mean stops bending? This presumably would be the same distance that would enable effective bow tuning. i assume there would be a difference between recurve and compound.

[geoffretired]

I have watched slo mo vids of arrows being shot at 70m with recurves and they are still bending back and forth when they land.

[bimble]

Arrows do flex a bit with compound, only vertically (there was a slow-mo of Archery-mum on a thread in the last couple of days).

Just wondering Geoff if that's when they're landing, or jut before they are landing?? If it's as they are landing I would say that the bending there is due to the fact the arrow isn't hitting the boss straight and the rear of the arrow is trying to overtake the front of the arrow.

Originally Posted by geoffretired

I have watched slo mo vids of arrows being shot at 70m with recurves and they are still bending back and forth when they land.

It's honestly scary just how much arrows flex when they hit. Sometimes I'm surprised that they don't break everytime they're shot!!

[King Custard]

I think its safe to assume that an arrow will oscillate till it runs out of energy, is it not?

In which case it's still bending until it disperses that energy into the boss (or the ground)...at which point rapid deceleration will negate that original 'bend' and impart another...

as said though 20 yards should the 'bendiest' part of flight out of the way.

[Jerry Tee]

There will be no difference as long as the bow ( compound or recurve ) is shoot off fingers.

[Mad Archer]

Originally Posted by King Custard

I think its safe to assume that an arrow will oscillate till it runs out of energy, is it not?

In which case it's still bending until it disperses that energy into the boss (or the ground)...at which point rapid deceleration will negate that original 'bend' and impart another...

as said though 20 yards should the 'bendiest' part of flight out of the way.

This must go back to the principle of conservation of energy - energy is never lost, only transformed (I'm ignoring relativity at this point).

As you let go of the arrow, you give it both kinetic (forward motion) and vibrational energy. Leaving out the kinetic part, the vibrational energy remains until it is converted into another form. The only transformations I can think of are the transfer of energy to the air (air resistance) and the internal flexing of the shaft generating heat.

I can't see either of these mechanisms reducing the vibration of the arrow very quickly, so I'm not surprised that slow motion shows the arrow vibrating all the way to the target.

[maxwell9699]

Okay. From the replies so far the consensus appears to be that the arrow is dropping as it reaches the target, is drifting sideways if the wind is blowing but is also oscillating side to side. So that means the archer has to shoot so consistantly that the left right oscillation concides with the gold, and this oscillation is greater at the shorter distances.
Damn this archery is difficult.......anyone got a rifle?

[geoffretired]

I think the left right oscillations have to be ignored as far as shooting into the gold is concerned. When the arrow is bending one way and the other, the point is moving side to side across a narrow range and there is no way of knowing which side it will be on at impact.

[bkupris]

I had a very interesting conversation in the "informal networking lounge" not too long ago with a very credible compound archer about this. Concerning the archers paradox and compound bows-he believes in the concept of setting centre shot slightly off centre to purposely induce a small horizontal arrow oscillation or a "push" on the arrow from a direction other than dead centre.

His thinking was it's better than setting centre shot at dead centre and then with a bad release with the trigger or other form problems the oscillation or "push" induced into the arrow could be more erratic in the horizontal plane.

Sorry going off topic a bit maybe but I found this very interesting and wonder if it is commonplace?

[madhatter]

I shoot compound..fingers..and the arrow rest is slighty off centre.
I seem to recall that it's the first 4inches of the arrow thats touching on it's way out, then it's in free flight....wibbly wobbling all the way to the kill.