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Making Flight Arrows Arrows specifically designed for Flight archery cannot be bought. If you want
to shoot competitive Flight, you must make your own arrows (or find a willing
soul to do it for you). This actually has the advantage that you win or lose by
your own efforts.
a. Target shafts . The British compound record of 817 yards was shot in 1996 with 480 mm (19 inch) Flight arrows made from 4.5 mm Easton PC carbon target arrow shafts. These were the smallest diameter arrow shaft Easton's made. The advantages with this material are that it is stiff and, because the shaft is hollow, it is light (5.49 grains, or 0.356 grams, per inch). It is also very easy to make nocks and points that can be fitted into the ends. But the interior diameter is 2.7 mm, and the arrow's walls are less than 1 mm thick so, when barrelling the arrow for better aerodynamics, one has to be very careful not to weaken the side walls too much. b. Solid carbon rod , introduced into Flight archery by American archer Rulon 'Ike' Hancock in 1975, is what most Flight archers use today. For low poundage recurve Flight bows, with arrow lengths around the minimum 14 inches, 3 mm diameter is sufficient; for heavier recurve or compound Flight bows, 4 mm is preferable. With 3 mm carbon rod, barrelling is not practical and the shaft is left with parallel sides. The use of 4 mm rod allows for a fair degree of aerodynamic shaping. I taper the ends to 3 mm and make 3 mm points and nocks. c. Wood . Until Ike introduced carbon, cedar wood was used exclusively for Flight arrow shafts. And cedar is still used by some archers today. Cedar is light and, unlike carbon, clean and easy to shape. Its one disadvantage is that to get a stiff enough spine, it must have a larger diameter than carbon — and that means more friction through the air. Shooting wooden arrows is a distinct disadvantage in competition with archers shooting carbon. Even so, Flight archers with wooden arrows still manage respectable distances. For my compound bows, shooting between 25kg (55 lbs) and 33 kg (72 lbs) I use
either 4 mm solid carbon arrows at 15 inches long or 4.5 mm hollow arrows at 19
inches long.
Weight of arrow The aim when designing a Flight bow is to get the maximum speed out of it. One
of the parameters which determines speed is the weight of the arrow: the
heavier the arrow, the more energy it takes to overcome its inertia and the
slower it will leave the bow. So the lightest arrow possible is desirable. But
it can be taken too far. There are two trade-offs: firstly with arrow friction
through the air, and secondly arrow to bow tuning.
AerodynamicsSo your bow is efficient, your arrows leave it fast. After that, it is up to the arrow to make the most of that speed. This is where aerodynamics comes in. I have divided this aspect into three: Drag coefficient, Centre of Gravity and Fletching, all of which are interdependent. Drag coefficientThe ideal shape for an arrow is similar to that of the javelin. By making the
arrow a very elongated, slim oval, pointed at both ends, you can decrease its
drag coefficient, and thus air friction, by up to fourteen percent while at the
same time reducing its mass (weight) by nearly twenty percent compared to a
parallel-sided arrow with a similar spine. (The nock spoils it slightly.) This
minimises the trade-off for the Flight arrow of mass versus drag coefficient:
we reduce the drag by reducing the mass ? with no loss of spine.
Centre of Gravity The next consideration is the Centre of Gravity (CofG). A Target arrow's CofG
is usually in the order of 8% to 13% in front of the centre
point of the arrow. This is to make the Target arrow stable which is necessary
for consistent groups on target. In Flight we are not interested in groups, but
in distance.
Figure 1 The disadvantage is that such an arrow is highly unstable. An arrow with a
heavy point and a CofG well in front of the arrow's centre will shoot in stable
flight without fletches. But put the CofG at or behind the mid-point of the
arrow, and it won't shoot without fletches at all. So as the CofG approaches
the centre of the arrow, fletches have to be bigger to stabilise the arrow. And
the bigger the fletches, the more friction there will be through the air.
Figure 2 In an attempt to resolve the debate, an American engineer and archer, Dr
Clarence Hickman, conducted a series of experiments in the 1930s with a hollow
metal arrow. Dr Hickman fitted a moveable weight inside the shaft which allowed
him to vary the arrow's CofG without changing its overall weight. The arrow was
shot using an 11 kg (24 lb) bow mounted at 45E in shooting machine. The results
he achieved showed clearly the advantage to be gained from having the CofG
forward.
Fletching
From what has already been said, you will appreciate that fletches should be as
small and light as possible. The most popular material until the advent of the
computer age was razor blades. These were easy to shape and fix onto the then
popular wooden arrows. Today, pieces of floppy disc are the norm.
Target class arrowsThe Target bow classes are for archers to shoot their standard Target equipment
— and that is what they should do. However, some Target arrows are better than
others for Flight. The simple rule is: the lighter the arrow, the faster it
will leave the bow and the further it will go. Any archery shop catalogue will
tell you the weight of arrows, from which it is easy to work out the ACEs
should be the best.
Last updated 30 January 2003 |
"NH&WL may be the best non-technical book on diet ever written"
Joel Kauffman, PhD, Professor Emeritus, University of the Sciences, Philadelphia, PA |