LAST ?? on spine(from me!)
So I'm clear on all this... 28" is the standard measurement.
add 5# for every 2" additional draw-length.
What about the additional length of the arrow sticking out in front? I know one doesn't need much extra,but currently the arrow head rests on my thumb knuckle,and makes me nervous. Also I want to try the bow hand technique with the forefinger supporting the arrow,so 35-36" would do it. How much heavier would anyone estimate the spine should be for that?
Remember my other post info(32-33"draw,40-43# at that draw,33" long,55-60#spined PO cedar shafts,125gr field points,and the arrows tend to stick with the shafts angled away to the right.)
thanks for any more thoughts,And I won't bug you anymore! :-)
And I know you are all estimating,not actually seeing my equipment,so no I won't ever complain!)
Any additional lenght, sticking out or not, will make the shaft act more flexible, though not always something to be bothered about. You could probably decrease the pile weight.
Shooting with a thumb ring, the main effect of spine I see is in the distribution of arrows to the left or right of the centreline of the target. With a consistent aim it is easy to see the dynamic action spine. This is not quite the same with a three finger release where there are issues with the arrows passing the bow as well. I know people who have compensated for arrows that were too stiff by making them longer than necessary which corrected their flight. This is not an optimum solution because the longer arrow is heavier and therefore does not have a flat trajectory. This means more compensation when aiming. at different distances.
Old Arabic works mention three different positions for the arrowhead at full draw, the greater, the intermediate and the lesser. In flight shooting, there was another called the jinkilbaz in Taybugha which has been interpreted as "hawk's claw". Even when the arrowhead was in advance of the back of the bow, it was still in contact with the thumb. In the Middle East, the choice of these draws was determined by stature and the relation of the shape of the body to the length of the arms.
thanks for the input. I'm trying to narrow down my problems(which are many... :-( ) I'm trying to shoot Khalka or Buriat style,which, as you are likely aware,involves coming either to about the pectoral muscle of the draw hand, or closer to the clavicle. I have difficulty maintaining consistency there,as I'm frequently eyeing(somewhat nervously I might add....) the arrow point as it's coming backward over my thumb. A longer shaft(2") would fix that.
I've mentioned that my shots nearly always stick with the nock end angled a bit right of center(no matter if they are accurate or not) occasionally they slalom a bit on the way, but not consistently, and usually I can feel it was something I did wrong with the thumb-ring. I promise not to hold anyone accountable here- Can you make an educated guess as to whether my current spine(55-60) is too weak, too strong, or is it just me? If it's too weak,then I can go for the longer,heavier spined bamboo, and heavier points if I need to. I do understand that the heavier arrows have poorer trajectory.
Thanks,
Boghadair
Promise not to drive you crazy any more! :D
Grozer Chinese Biocomposite. 33# at 28" and 40# at 32"(measured on an electronic scale. Target shooting,field courses. occasional clout shoot, but I'm sure that's under 200 yds.no hunting
Boghadair
Bamboo arrows would be very out of place for that style. An (Asian) Poplar, birch, pine or similar barreled shaft would be appropriate.
I think we have been over all the diagnostic techniques for arrows. It takes some experimenting to get to the optimum ammunition.
Mongolians using thumb release are turning increasingly to shooting on the left of the bow. Make a different thumb ring. Try everything. That is a light bow and you are unlikely to do damage. By all means read your old threads.
Khalkha and Buriat are tribal distinctions,the Khalkha being a majority, and living in the middle and more southern regions,while the Buriat inhabit country much more towards Siberia. their equipment is similar for the Naadam(which is the national sports festival, focused on horse-racing,archery and wrestling.) yes the arrows and targets are totally different for that, with sort of woven leather baskets laying on the ground being the targets. The folk I shoot with here use field points and foam targets,so my reference to shooting style is primarily in regards to the draw and release.
Does no one here want to make an educated guess(based on my observation that my arrows all mostly end up with the nock angled off to the right) as to whether 55-60# is too stiff, or not stiff enough?
Thanks,
Boghadair
Jack is accurate in stating that many modern Mongol archers are now shooting on the left side of the bow. Professor Seded Batkhuyag explain this to me as being a way to correct an aiming problem that they were having. This shows that Mongolian archery is still dynamic and prepared to experiment.
In the Middle East, having the arrows not landing perfectly straight and horizontal in the target was considered to be a fault. Slapping of the nock against the arrow pass on the bow is considered to introduce irregularity in the flight of the arrow. several things can cause this. If your arrow wags in flight, this might be the cause. If it travels nock right for the whole of the flight there could be another cause.
In general I would look at how tight the nock grips the string (excessive tightness affects the regularity of the flight of the arrow). Check how hard your index finger is pressing against the nock of the arrow. If the nock is loose and the pressure is slight, the arrow might be getting an off-centre push from the string. if the nock is a good fit and the pressure is too strong then deflection can be introduced.
It is important that the arrow be perfectly straight at full draw and not bent by the pressure of the index finger. If it is not stiff enough this bending can accidentally occur.
One test is to double the distance and see if the arrow still lands nock right.
both helpful answers.(Not that Jack and the rest of the group aren't!)
there are only a few thumb-ring shooters around here,and they know less than I do,so I'm pretty much on my own. I'm not at all insulted by the implication that my shooting form might need work.Whatever it is at the moment, it's not consistent! At 20 yds, I may get 6/6 in a standard FITA target face,but maybe that's 50-60% of 120 shots. 75/80% hits is more likely at the moment.
currently my ammo has plastic snap-on nocks, and even though they are all the same type, they varied in tightness on the string,so I did take a file to enlarge the slots. As I understand it,(maybe from Stephen Selby) an arrow hanging from the string should drop off after a tap on the string?
as for length, PO doesn't seem to be available more than 32" anywhere,and I'm not equipped to foot shafts. I'll see if I can get the long bamboo and experiment
Many thanks to all of you for your input.
Boghadair
I'll see what happens at 40 yds.
Thanks,
Some batches of plastic nocks can vary quite a lot, but you are right, a tap on the string with your finger should see the arrow fall.
Have a friend at your club check the arrow flight, they will see more than you and may even see a possible release fault (even if they have no idea of correct form)
Arrow experimentation is a great pastime, often you will find more than one set up will suit your bow. Be aware that the usual push on piles may cause a headache when using bamboo shafts because they are hollow, this is why I advised a self nock which is the easiest option. Up front you may need a small piece of wood (from an old POC arrow) glued into the bamboo to stop the glue going up the shaft.
I made bamboo arrows of various weights from the Pseudosasa Japonica I have in my garden. All were around 8mm diameter but the density of each culm sidewall varies a great deal, the difference in some shafts was as much as 100 grains. The bow is around 48# at 30" and I had good results with (finished) arrows of 350grains up to 420grains and no noticeable difference in flight. Obviously over 50m or more there would be a difference in cast but at 20m performance was just about equal. All these arrows had light 60grain piles.
Good luck.
The follow through can also be an issue with a long draw. The Koreans, Manchus and Japanese all end the follow through with the drawing hand pointing directly away from the target. However, the hand is travelling backwards in a straight line relative to the arrow flight. The straight line disengagement from the string is what reduces the tendency of the hand to pluck the string on release and thereby add instability to the arrow flight.
Stephen's comment about the nock dropping off the string at a tap is a good rule of thumb, but even looser nocks will work if handled carefully. Their problem is that you require more concentration on the position of the arrow and that is not what you need right now.
Good luck.
Bede, it seems I confused the matter taking simplified approach but didn?t we were writing about the same thing actually? Of course lengthening the arrow won't change it stiffness, but the longer arrow will act in flight like a more whippy arrow, do you agree?Bede wrote:
I have to disagree with Ashbow. It has been my experience, and it is also present in the literature, that mass in advance of the back of the bow does affect the spine, though it has no influence on the stiffness of the shaft.
Shooting with a thumb ring, the main effect of spine I see is in the distribution of arrows to the left or right of the centreline of the target. With a consistent aim it is easy to see the dynamic action spine. This is not quite the same with a three finger release where there are issues with the arrows passing the bow as well. I know people who have compensated for arrows that were too stiff by making them longer than necessary which corrected their flight. This is not an optimum solution because the longer arrow is heavier and therefore does not have a flat trajectory. This means more compensation when aiming. at different distances.
The stiffness of the shaft is today often regarded as the ?static spine?, meanwhile it seems that many people tend to regard the spine value literally as stiffness. I?m really horrible at physics, but I?m aware that the spine when considered as a dynamic characteristic is affected by more factors than just stiffness.
The longer than the draw arrow is good for the short distance accuracy, at least with the three-finger release.
I find you comment very true, I still tend to bend the arrows (spined 50-55# with a 50# @ 28? bow) at the full draw because of the index finger pressure, of course my technique is still far from good.Bede wrote:
It is important that the arrow be perfectly straight at full draw and not bent by the pressure of the index finger. If it is not stiff enough this bending can accidentally occur.
Boghadair, I would go for Orda Khan?s advice, if you can try to play with lighter pile weights first and then see what happens.
It seems we are on the same track. Stiffness is measured with arrows suspended between centres as a deflection. This is then applied to the model of a standard arrow and said to be the spine of the shaft. This is only true of the arrow thought of in the model. If the arrow is cut shorter than standard it is stiffer and its spine goes up. If the bow is heavier that in the standard model, the stiffness of the arrow is the same but the spine goes down.
What this means is that stiffness is the measurement and spine is a quality taking into account the environment (the bow weight, brace height, the speed of return of the limbs etc.). Once you have tested a certain type of arrow on your bow, you can relate that to spine charts and work out whether an arrow will perform well on your bow or not.