Shooting Machine for Recurve (Hooter Shooter) "Home made" video slow motion

M

Moose

Guest
Like the fingers, nice idea, shows how well matched the arrows are to the bow as you could almost remove the button when shooting from the machine.

Would be interesting to use the machine to test arrow stiffness and bare shaft tuning to see how much use bare shaft tells you other than your technique has errors

Courtesy of iMoose
 

geoffretired

Supporter
Supporter
Moose, what do you think would happen if the machine shot fletched and bare shaft arrows? Take some that could be matched and some that would be quite well outside the range.
I'd expect to see bare and fletched together for matched sets. Bare and fletched in separate groups for unmatched, as they are when shot by archers.I'd expect good groups in all cases, with the machine.
Perhaps a spread if the match was poor enough to give contacts.
 
M

Moose

Guest
I would expect that unless the spine was well out that the bare and fletched should group together

Would also be interesting to see what happens with these arrows with no button

My theory is that when the arrows are only a little off spine and especially when too stiff that it is the loose that causes the bare shaft to drift and not the arrow

Reason for this theory comes from compound by removing the archers paradox we shoot stiff arrows (weak arrows will be a problem for everyone) as that relies on something correcting the bend when the arrow starts to move, therefore the more paradox the more the fletchings need to do something.

Courtesy of iMoose
 

geoffretired

Supporter
Supporter
My theory is that when the arrows are only a little off spine and especially when too stiff that it is the loose that causes the bare shaft to drift and not the arrow
Bow hand torque can produce the same effect, specially noticeable on compounds.
When you say the "loose" causes the drift, do you mean the bad looses or all looses?
All looses put a bend in the arrow during the power stroke, so the timing of the power stroke to the point of release and the flex rate of the arrow, when matched, can give the situation where all arrows (fletched or not) land in one group.
 

hooktonboy

The American
Ironman
American Shoot
My theory is that when the arrows are only a little off spine and especially when too stiff that it is the loose that causes the bare shaft to drift and not the arrow
Interesting. I think its the excessive stiffness - i.e. if the arrow doesn't bend enough it goes where is is pointed..... Difference between bare and fletched is drag?
 

joetapley

New member
I always imagined that the button would be doing a lot more.
You can't tell from a video how much a button is "doing". If say you replaced the button with a bolt then on the video you would see nothing yet the button would be doing a great deal more. The button spring act as a force limiter between the riser and the arrow. When the arrow is released the front of the arrow presses sideways on the riser. This force increases until the spring preset force is reached. The force does not significantly increase further, instead the button plunger moves into the barrel. The overall force between arrow shaft and plunger is a combination of the spring force and the inertial force from the plunger acceleration (the latter effect is the reason high quality buttons have very light plungers).

By changing the spring tension you can control the sideways force on the arrow shaft from the button. The effect of the button plunger on the arrow is the same as that when any force is applied to any object, a linear acceleration and an angular acceleration. In the case of the button spring the arrow property you are adjusting is the rotation of the arrow - this is the "tuning" parameter applicable to the button spring and is the main adjustment related to bare shaft tuning.

So with the mechanical release (nice job - but don't take it as being too realistic) you will still be able to move the fletched and bare shaft arrows around as normal with button spring variation as long as you have gone through the usual bow set-up routine. Should mention I suppose that bare shaft tuning has nothing to do with "spine". Archers often confuse bow set-up and bow tuning.
 

E=cap

New member
My machine is not to setup the bow, but to sort the arrows with the paradox effect, like an olympic archer. I improved between 2010 and 2011, 15 points my average on Fita and gain 26 places on French ranking.

If you have only one arrow on your quiver shoot only 9 at 1 cm of the 10 when you shoot perfectly, 12 points can be lost. And it's very easy to see the arrow which touch only 9 or 8 zone often, and exclude but not those touching 9 or 10 zone, we are not a machine, the best shooters can sometime score 350/360 points at 70 meters, my machine, with a new set of 12 Nano Pro always 360/360.

I did a test last year with the 6 best models of arrow and you can see the result:



Each set purchased on archery shop, not selected by Easton, Carbon Express, Sky Art or by Beiter machine.
Duret? on yellow means hardness, test with a tools of 2 pounds project on the middle of the arrow and the mesure on mm is the crash.
 

joetapley

New member
My machine is not to setup the bow, but to sort the arrows with the paradox effect, like an olympic archer. I improved between 2010 and 2011, 15 points my average on Fita and gain 26 places on French ranking.
I see the point. I agree results probably more relevant than say Beiter radial spine test (though not so fast :) ) as your testing the whole arrow rather than just one aspect. A mechanical equivalent of the Frangilli 70m bareshaft selection process.

Query: on the target face image - what was the distance/target size and what are the large black numbers e.g. X10-358-13x.

I assume durete is a metric Easton spine value?

PS penny dropped: Numbers are some relative score and number of inner ten values.
 

E=cap

New member
Test was done at 70 meters on 122 cm target.
from left to right on the top on black: Model of the arrow, score of 3 ends x 12 arrows, number of X10 on 36 arrows.
On white, speed of the arrow with Easton chronometer.
On blue, weigh on the arrow in grain.
On Yellow the mesure between the intact shaft and the shaft after the crach by the tools in millimeter.
After this experience, I know now, why you paid 100 to 200 euros more a set of 12 arrows between
More expensive set:
Easton X10
Carbon Express Nano Pro
Sky Art B92
and less expensive set:
Easton ACE
Carbon Express Nano XR
Sky Art Jade
 

julle

New member
damn, so ace's turned out to be the worst shooting arrow of the bunch? where they the right spine, or are they just really badly matched?
 

joetapley

New member
damn, so ace's turned out to be the worst shooting arrow of the bunch? where they the right spine, or are they just really badly matched?
Test says nothing about which is best or worst arrow. Only testing a small sample (12 arrows) and measuring overall consistency of manufacture. (In fact using fletched arrows distorts the results somewhat and really bare shaft arrows only should be used if you are trying to compare different arrow shafts).

To get a set of six shafts for top level competition then from reports you need to start with something like a population of 50 - 100 arrows.

Nearly all independent shaft tests/views I've seen reported by quality archers end up with something like 1) Nano Pro 2) ACE .... so no need for any despondency :) . Unless you can put in qualifying scores for the AGB Olympic team I wouldn't bother to much about which arrow shaft you use.
 

E=cap

New member
damn, so ace's turned out to be the worst shooting arrow of the bunch? where they the right spine, or are they just really badly matched?

I used 12 shafts totaly new from my archery shop and each arrow was setup with a special tools to put the 3 spin-wing exactly at the same place,
The tools is not that Beiter or Spiga produce, but one I design.
X10 was spine 600
Nano Pro was spine 600
B92 was spine 600
ACE was spine 620
Nano XR was spine 630
Jade was spine 620

With my bow force, each model was perfectly setup, so my test was very equal for the 6 models.
Maybe with the same test with 6 new sets, we can have a little difference, but I tested a lot of Nano XR (mine) et a lot of X10 (friends)
and the result was very near from my first picture showing on this forum.
 

Vittorio

Member
The test results (remarkable, anyhow!) says how good is one set of arrows today, as purchased from a shop the day before. Results are related to the yeld you can get of good to bad arrows from a set of different arrows. Nothing statisycally valid, but for sure a good indication. If arrows were numbered and registered for each shot, we could easily see how many relly good arrows were available in each set.

From all tests performed in the years, for sure Nano Pro have been the most consistent in one single setm of 12, with a yeld for bare shaft of around 10/11 over 12 that may become 12 over 12 with fletching.
For ACE's is a different story. Yeld until the 2000 was close to 70%, or 8 over 12,while X10 were at that time just over 50%. But in recent years yeld is dramatically dropped for ACE's, and is not uncommon to get very bad sets with less than 50% yeld, while X10 have slightly increased their consistency.
Also, not statisticallly valid numbers, just refrences from several test performed in the years.
At present, at national team level, it is known "by experience" that to get 12 workable arrows for top level competition you will need probaly 13 Nano Pro, 20 X10 and 30 ACE's. Other arrows are usully not used at top level, so I have no references for them.
A good question for Easton should be why their quality for ACE's is dropped so much in the years. Some malicious comment has been that if they did not drop the quality of ACE's sets, they could not sell X10 as "better" arrows.... I can't beleive this, I just imagine that material (carbon) quality and some production process are changed during the years.
Unfortunately for archer's pockets, above yeld numbers have nothing to do with arrow performance when shot with fingers from a recurve bow in a top level competition. Just changes the real final cost of a top performing selected arrow...

Quite often I have imagined a situation were the amateur archer returns "not good" shafts to the shop and gets replacement for them... It may happen, if archer is in a condition to measure tolerances of the arrows he has bought and demonstrate they are out of published specs and tolerancies. But I'm curious to hear if it really ever happened anywere ...
 

julle

New member
o thanks for saying that vittorio, my confidence just dropped like a brick :p
I always noticed flyers in my ace sets, but never really investigated it because i was just to scared to realize they really are bad, and that wouldn't do me any good because I don't have money to buy another set :p It's just totally ridiculous that we have to pay this kind of price for shafts. Last year I had a complete set break just behind the point, the shop nor easton did anything about it.....
Vittorio, I read your book and saw the picture of Michelle with the bare shaft test, i'm wondering what happens to the cast offs? Do you just send them back to the factory?
 

joetapley

New member
At present, at national team level, it is known "by experience" that to get 12 workable arrows for top level competition you will need probaly 13 Nano Pro, 20 X10 and 30 ACE's.
Thanks for the correction/update - must be getting more pessimistic with age

vittorio, my confidence just dropped like a brick :p
The key comment here is "Unfortunately for archer's pockets, above yield numbers have nothing to do with arrow performance when shot with fingers from a recurve bow in a top level competition. Just changes the real final cost of a top performing selected arrow..."

If someone makes a consistent Ford Escort and somebody else makes an inconsistent Ferrari, in the race the Ferrari is still going to win.

I've seen the "all arrows fail behind the point" syndrome a fair number of times. The usual reason IMO is shop fitted points. Assemble arrows yourself if you want it done properly.
 
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