Tag Archives: Tuning

Preparing X10 Arrows, or “how much is too much?”

Arrows need to be assembled, unless you are working with fiberglass arrows.

For the vast majority of archers, this is the priority in arrows:

  • Right Length (so the arrow does not fall off the rest and go through the hand)
  • Sufficient Stiffness (so the arrow doesn’t whip against the bow as it is shot)
  • Correct nock (so that it does not fall off the string)

Once the archer is beyond the first few weeks/months, and wants to “move up” and buy her/his own gear, I usually suggest purchases in this order:

Finger tab – the most personal piece of archery gear, and one of the most critical. At this writing I recommend ONLY the Black Mamba finger tabs.  I’ll write about them soon and why an archer would want them over the others out there on the market.

Arm guard – needs to not be the bicep-to-wrist covering length which just potentiates bad habits. The simpler the better, and the smoother, the better.

Riser – Generally has to be bought at the same time as limbs, but some clubs will have loaner limbs (desirable especially in younger archers where strength and bone growth plates are still active).

Limbs – as skill evolves, so does strength.  Limbs are the energy handling part of the bow and the dynamics dictate a *lot* of things.  I suggest any archer always save every pair of limbs owned, so as to have a library to choose from as future circumstances (say, recovery from injury, change in methods) might dictate.

sight, plunger, clicker – these are relatively inexpensive and purchase usually comes with the riser if the archer is inclined to acquire accuracy at  longer distances.  Barebow archers sneer at these, of course.

ARROWS.  back on topic!

Arrows are chosen by environment:  Hunting, Outdoor Target/3D/Field, Indoor Target.

Hunting arrows carry heavy tips and need lots of stiffness.  Enough said since they are a whole ‘nother topic.

Indoor – briefly, they can be thicker, cheaper, aluminum arrows with larger feather vanes.  Since indoor distances tend to the 18 meter length, you want aerodynamics exerting effects faster, hence the larger vanes/feathers.  Some archers feel they get a scoring advantage with large shafts (“guppies”) that might cut a line and yield an extra point.  Most world records, however, have been set with slender arrows in recent years, though not all.

To the outdoor target/3D arrow:  The hollow, carbon, or carbon/aluminum arrow, especially the X10!

These are a good example of the height to which our civilization’s technical abilities have risen (much like the riser and the limbs).  The most medals, probably 99% of all archery Olympic medals since 1972 (when archery was re-introduced into the Olympics) have been won with an Easton Arrow, and the majority of those were with the X10 arrow, an aluminum tube-wrapped-in-carbon-fibers-embedded-in-a-carbon-resin shaft which is barrel shaped to provide an accurate, aerodynamic performance even without vanes.   These shafts are strictly uniform in weight and stiffness, such that the factory actually rates them into batches of 12 shafts that are closely identical (not perfectly, however!).

The arrowheads for X10s are actually called points, and the most common form in use is a stainless steel point with a smaller shaft portion that is inserted into the hollow front end of the X10.  By the way, what I describe for the X10 goes for the other similar shafts, including the all-carbon versions.

The points have notches in the insertion part, so that you can change the net weight of the point by breaking off a section.  Breaking a section off is fairly simple, requiring two sets of pliers, and a careful technique to avoid bending the rest of the point’s shaft.

To mate them with the shafts, the points are heated slightly with a clean flame, some special hot glue (supplied by the manufacturer) applied to the insert portion, then pushed into the front end of the arrow shaft and held steady for a few seconds until the glue “sets”.  Excess glue is removed with fingers.  With a little practice, the fix is permanent and the points are in for good, but can still be removed with gentle heating of the tip if needed.  Heat must never be applied directly to the carbon shaft as it will cause the front of the arrow to weaken and perhaps crack sometime during its future.  If the glue become liquid or fluid when applied to the insert shaft, it is too hot for the carbon , so wait until the glue become viscous before inserting.  If you cannot hold the point in your bare fingers, it is likely too hot.

In preparing one archer for a major world championship event, I was driven to get everything as right as possible.  Since I had a scale at the pharmacy that measures accurately down to just a few mg, I decided to really get precise.

First, I got 2 dozen new X10s courtesy of my archer’s sponsor, Easton, and I confirmed the arrows were all the same rating.

After cutting each new shaft (of 2 dozen) with meticulous care, working outside with an Apple arrow saw, I used a can of compressed air, with a straw attached, to blow out all dust from inside the shafts.  (never breathe the dust during cutting/cleaning)

Then use a paper towel soaked with either 70 or 91% rubbing alcohol to rub down the outside of the shafts.  Use just enough pressure to feel the shafts resonate as you do this, and change the surface of paper contacting the shaft frequently. You’ll see a good deal of dark residue the first pass, and less with the next pass.  Don’t overdo this, and be careful using 91% alcohol as it is flammable – burns with an invisible flame (!). Also, while some will recommend using acetone or mineral spirits, I dislike (as a pharmacist) using such toxic chemicals that are sure to be absorbed through the skin.  Some may also harm the resin, shortening the life of the arrows and/or affecting accuracy as they age.

Next, clean the inside of the tube where the points and pins (for pin nocks) will be glued.  I use 8″ long pipe cleaners which come in packs of 30 or 100 at party stores and Arts/Crafts stores.  Cut them in half with scissors once and you have a lifetime of cleaners.  Dip one end of a cleaner into the alcohol for an inch or two, then insert carefully into the arrow shaft.  Some will drip, so be careful.  Insert/remove the cleaner once or twice each end, and discard.  Take a dry cleaner and follow the same in and out a couple of times.  The cleaner should not have much dark residue discoloration – if you are in doubt, repeat the process.  NOTE that you don’t need to clean any deeper than the point will reach.

Here’s where I got really obsessive-compulsive.  I do realize that the density of the resin causes a variance in the “per inch of shaft” weight and stiffness, and it’s impossible for me to equalize that variance.  But I can take some steps to even out the net weight of the arrow, and the variance between point weights.

I weighed each arrow shaft at this point, and used post-it notes to label each, and I laid them down in order of weight.

I also recorded the weight of each on paper, and then found the average weight, the max, and the min weights.  There were almost no identical weights, by the way, given that my scale was so precise.  It is able to weigh a single grain of salt, for example.

Next, I took the points, and thoroughly cleaned them with alcohol to remove all machine residues and grime.  You want to do this in any case, even if you are not going to weigh them – the cleaner the “glue” sites are the better the glue will work.

If you weigh all of the points, each will vary slightly as well.  If you have to break off a section (or two) in order to get to the right dynamic spine of the arrow, you introduce even more variability to the arrow weight, the spine, and the grouping behavior of the final arrow product.

I broke off a section for each point, and then I did the same weighing series, and post-it labeling.  I compared the max weights and min weights, to calculate what was the best combined weight I could use as a target value for all arrows.  In other words, how could I combine a given point with a given shaft, and end up with the arrows weighing as close as possible to each other.

I had some combinations that were “outliers” on the too-heavy side, even after swapping combinations around.  For those, I carefully lightened them up using a dremel/grinding wheel on the break-of end of the point, and then carefully cleaned them.

When gluing the points, I was careful to apply enough glue to fill the break-off valleys.  I doubt the glue all stayed there in those valleys, but I know that at the start of insertion the amount of glue was the same.  Once they were all glued, I was surprised at how little more weight they gained from the glue, and there was next to nothing in the way of variance.  Also, clean your fingertips with alcohol frequently to eliminate the oils that will leave discolorations, if you are as obsessive as I am ;)

I was likewise very careful gluing in the pin nocks, regarding weights and glue use.  The final 24 arrow products were all as uniform as I could make them in terms of weight overall.

My archer was able to shoot groups with bare X10 shafts from 70 meters which made this next much easier – remember that X10s have good aerodynamics due to barreling which no other shafts do.  If your archer isn’t that consistent then use a distance that works best.  All shafts were uniquely numbered, and we kept track of the top performers over several days, selecting Team A and Team B groups.  We then fletched 8 of each team with kurly-vanes, leaving 4 bare shafts for tuning purposes in each team.  I don’t see any functional difference between spinwings and kurlys, but the archer liked the bling factor of the kurlys (red holograms in particular), and whatever makes the archer happy…

At the end of the tuning process the bare shafts were impacting at 10 to 11 o’clock, within 2 rings of the fletched group center at 70 meters, so we then fletched the rest of the arrows and called it a done deal.

I did not do this before Athens, and I have always fretted about leaving something on the table ever since.  Doing whatever YOU feel is worthwhile, will leave you able to sleep nights as a coach.

Note: if I was doing this again, I would consider: fletch ALL of the arrows initially, then TAPE down with vane tape the vanes, so they have the weight at the back end with none of the aerodynamics, and compare behavior.  An engineer I greatly admire at Hoyt used this method, and I’ve sometimes wondered whether the ensuing drag was a greater influence than the weight, in terms of evening behavior out when bare-shaft-testing the bow’s tune.  It’s probably a wash for all but the top 1% of archers, but it certainly bears testing.

Know The Bow. Teach The Bow. Tune The Bow.

If you want to really get to know a new bow well, or perhaps just learn more about the influence a given part of the modern recurve/Olympic bow has on the system then you might consider following the example of the military.

Most will know that the typical soldier is taught to completely dismantle and then properly reassemble a weapon, so often that they will dream about it and even do it blindfolded.  NOT suggesting anything quite so drastic for you or your archer, but as a coach you should do what I am about to suggest.  Once you have done it you may see the value in having your students do this, particularly those that are showing promise of becoming dedicated to the sport.  As I well know, the coach does not get to be there at the most important matches and it is coach’s duty to prepare the archer for those moments.  Knowing the bow and ALL of the components and how/why/when to change them effectively is crucial to reaching the top step.

Start with:  riser, limbs, served bowstring, arrow rest properly attached relative to the thickness of the arrow shafts, arrow shafts with nocks/points(no fletching), clicker if you will use one, and plunger.

Set the plunger to have no give, using Rick Stonebraker’s matchstick method, or else if it is a Beiter you can probably just tighten the spring down till it doesn’t move.  We want raw influence, no “buffering” by the spring that might lessen visual evidence.  Set the depth of the plunger to the skinny/shallow side, where it is just barely touching the side of the arrow shaft.  Set the brace height to a middle-of-the-mfr-spec, and set the tiller to zero.  Put the nocking point(s) to zero with a bow square.  These settings are going to wrong to some degree (we want that!), and you are going to set them right by shooting bare shafts (only) close enough to the bale to not miss it, but far enough away to allow the arrows to be in the air as long as possible.  You will want to pay attention to the symptoms, that is the way the arrows fly.  Minnowing up and down, porpoising left and right, wobbling because of excessive weakness, flailing because of a grossly high angle of attack from a really wrong nocking point, skewing due to the hugely wrong centershot, are the clues you want to see, and ultimately eliminate on your way to perfection.

Also you want to note the angle of the arrow in the target.  It will be off perpendicular, but with tuning you can make it less of an angle, and if you play your cards right, they will look just like fletching arrows!  With X10 arrows, the barreling causes enough aerodynamic influences that even at 70 meters an elite archer will find his way to the gold routinely, regardless of whether there are vanes on the shafts.

Let’s start with the premise, that a perfect tune for the archer’s technique will result in the energy from the bow pushing through the center mass of the arrow completely, yes, well, “perfectly”.  When it does that, it is a joy to witness, a knowledge of perfection for a brief moment.  The feeling every archer strives for, “YEAH, I did that…”.  When a bare shaft arrow porpoises, when it fish-tails, flails about, energy is being lost because it was injected off-center.  So tuning is bringing the elements to balance, to harmony, to reduce the energy wasted outside of the center axis of the arrow.   “Tuned”, the arrow behaves like a dart, and its flight is a beautiful thing of purity to behold.

SO!  With the plunger “off” and the tension on the spring 100% so it doesn’t give, the center shot off, the arrow will minnow left/right.  With the nocking point wrong, the arrow shaft will porpoise, up and down.  Fix the nocking point first because it is simplest.  For this exercise, use a tied-on floss nock, with sufficient tension so it can be rotated/screwed up and down the serving but stay set between shots.   Shoot, adjust, shoot, till the arrow no longer porpoises up and down, or at least, does so as little as possible.

Next, change the center shot gradually by moving the plunger deeper into the riser and pushing the arrow further from the riser.  As with the nocking point, you are learning the impact on the flight of the arrow this device has.  And as the minnowing decreases you know you are getting closer to the better center shot setting.  As it re-increases you know you have probably passed that point.

Through all of this you must decide each shot whether your release messed with the arrow too much and caused an energy diversion, or whether your release was as good as the tune at that point.  Do you see truth or artifact?  When you minimize minnowing, you might re-visit the nocking point position.

I was taught by the greatest coach I have ever met that tuning is like kneading dough.  Adjusting the nocking point in the right direction is like pushing a ball of dough down, which makes it (the arrow pattern) squeeze wider.  So you adjust the plunger, squeezing the ball taller, more vertical (the arrow pattern).  Working in the right direction you gradually end up with a round ball of dough (the arrow pattern) that is smaller than when you began.    The size of the ball at the end depends also on the spine of the shaft – a just-right spine’s doughball will be smaller than that of an arrow with too weak of a spine.  You ask about the too-stiff spine?  It will be smaller still but only when the release is perfectly consistent.  A too-stiff arrow will likely be unforgiving of an inconsistent release. And once you have fletchings on the arrow, a too-weak spine will be more at risk for hitting the bow particularly with inconsistent releases.  A slower release – stiff fingers – magnifies the flexing of the arrow, all other things being equal, resembling a weaker shaft – “dynamic” flexing.

Once honed to the best bare-shaft arrow behavior, the perfect plunger depth/center shot, the ideal nocking point (for that brace height/tiller), it’s time to start weakening the totally stiff plunger to find the best arrow flight again.

React to the arrow flight, the angle in the target, and the pattern of impact points on the target face.  Remember that you will need to make smaller adjustments – for example, you may find that moving the nocking point by a single serving thread diameter yields a profoundly better tweak to the group!

Remember that fletchings serve to average out the imperfections – in the arrow shaft.  The point weight/forward-of-center. The tune.  The release.  The wind.  By causing the arrow to rotate through 360 degrees continually, the vanes reduce the flaws.  They were critical when arrows were wood and vanes were feathers.  As long as the device loosing the arrow is human fingers, there will be imperfections that vanes can mitigate.

SO that begs the question, in a perfectly tuned compound bow shooting with no winds, why are vanes useful?  Well, a compound bow needs tuning as well.  I suspect that due to the built-in accuracy associated with a bowstring in tracks with a string-guide, with a magnified sight with a level, and yes, with a defined wall and a mechanical release, most compounders never learn to micro-tune and are unknowingly relying on the vanes to mitigate subtle flaws in the tune.

Doing the things I suggest will result in a much better awareness/knowledge of the bow, the arrow, and the relationship the archer has to both.  It may even result in better scores.