Firenock:AeroBolts


Introduction of AeroBolt
    At the beginning of building AeroBolt in 2011, Firenock used common off the shelf components to build Aerobolt to address the issue of the weak front commonly found in high speed crossbow bolts.  The first generation of Aerobolt (Aerobolt I) performed fine, but Firenock found that common off the shelf components had concentricity issue and fundamental design issue and thus could not unleash the full power Aerobolt.  With our research data and with the introduction of Firenock AeroSystem, Aerobolt II was made which concentricity issue and weak front end issue were resolved and made Aerobolt II the best bolt available for today's archers.  Three models of AeroBolt II are now available, they are AeroBolt II-200 (AB20), AeroBolt II Dragon Slayer (ABDS), and Aerobolt II-G (AB2G).
    All AeroBolt™ II is loaded with Firenock US patented Self Concentric Technology / FACT Technology (Firenock Arrow Concentric Technology) and Hybrid Insert System.  The beauty of Self Concentric Technology is that AeroPoint and AeroInsert will self concentric to the shaft once assembled even without tuning.  Meanwhile, AeroPoint is equipped with our patented Double O-Rings System to eliminate the issue of loosening even after continuous shooting.  Hybrid Insert System (i.e. Firenock Patented Double Shoulder Insert with Carbon Extension) which not only strengthened the arrow front end but gave Aerobolt II a variable spine characteristic which this unique characteristic shortened the oscillation cycle of arrow (i.e. Aerobolt can fly straight and conserve energy).  These Technologies allowed Aerobolt II to fly straight and hit accurately and AeroPoint would not come off even after continuous shoot.

The AeroBolt™ II-200 (AB20)
AB20 crossbow arrow is engineered and designed for general purpose.  AB20 can achieve maximum flight stability and maximum speed with AeroPoint and most Aerodynamic design broadhead such as Traumahawk. AB20 is offered in lengths from 20" to 26” and is built with 0.001" straightness shaft.  The weight of AB20 (26”) with AeroPoint, AeroInsert, and Hybrid Insert is 325 grain excluding nock and point.  The amazing straight flight of AB20 is due to AB20 has a variable spine design (as a result of effect of Hybrid Insert), its spine in the front is 0.060” and at the back is 0.200". As a quality mark of Aerobolt II, they are spine indexed, hand marked with weight, length and manufacture date.

AeroBolt™ II Dragon Slayer (ABDS)
ABDS crossbow arrow is the big brother of the AeroBolt II.  ABDS is built for African Big Game and is heavy in weight as many African range game laws have stated you must use no less than a 1000 grain archery projectile for taking the African big 5.  ABDS is offered from 16" to 26" and is engineered to give maximum momentum and penetration power.  Unlike any other crossbow bolts, it has a 0.092" thickness of carbon throughout its entire length.  Unlike AB20 having one inner partial shaft configuration l, ABDS has two inner shafts that go through most of the length of ABDS.  The inner 2 shafts are engineered to be super heavy and super stout.  In addition, ABDS comes standard with Firenock AeroInsert-DS (S=Stainless) and Firenock 0.244" extreme shock end cap to fit the Firenock F, D, J, M, Q and V lighted nocks.  With this special construction, all components on ABDS are supported by 2 shafts and even 3 shafts.  With a 26" ABDS, the expected total weight (excluding point and nock) is about 750 grain (including Aerovane II).  This specification makes ABDS the ultimate African big game crossbow shaft.  From our field staff reports, it is also found that it is the best bolt for the huge 700lbs+ wild boars that roam the lower states such as Georgia and Texas.

The AeroBolt™ II-G (AB2G)
AB2G crossbow arrow is also designed for big game but with a light weight specification (325 grain??) and is designed to fit Firenock Aerodynamics Traumahawk broadhead.  The AeroBolt II-G design is different from AeroBolt II-200.  Aerobolt II-G is designed to have maximum front end mass in order to provide maximum to penetrate deep or pass through the big game animal.  Among the Aerobolts, AB2G can give you the flattest trajectory flight and a much longer distance with power.

Features of AeroBolt II-G:

  1. Spin over 2500 rpm with virtually no drag effect
  2. Frontal focus mass is over 200 grain
  3. Super straightness (0.006" or better)
  4. Fitted with Self Concentric AeroPoint 175 grain AeroPoint (10mm wide, 9mm base) as standard / Traumahawk as an option
  5. Equipped with Hybrid Insert System (40+ million modular carbon) for strong reinforced front end, straight and oscillating free flight
  6. Durable high modular carbon outer shaft (33 million modular carbon)
  7. Fitted with Aerovane III for quiet, light weight and no drag Aerodynamic high speed spin
  8. Initial first bend Indexed to achieve repeatable accuracy shot after shot
  9. Weight variation between bolts is within 3 grain to achieve repeatable accuracy

Note: All AeroBolt II are fletched with Aerovane™ II or Aerovane™ III vanes.  The standard vane configuration of Aerobolt II is 3 vanes (white, yellow and red). Custom vane color configuration, 2 vanes and 4 vanes are also available, but with extra charge.  You can also order your AeroBolt II without vane.  All Aerovanes on AeroBolt II are fletched with Firenock Precision Aerovane Jig and super strong Aerovane Glue AG0600.  You can also choose material for AeroInsert: DA is Aluminum (17 grain) and DS is Stainless (50 grain).  Furthermore, you can order Aerobolt II in your prefer weight and length.

The weight and length of standard configurations of AeroBolt no nock, point and vane are:

  Name   Length (in)   Insert Used (optional)   Carbon Insert Length   ~ Weight (gn)
  AB2 200   22   AID22A (AID22S)   7.5"   285
  AB2 200   26   AID22A (AID22S)   5.5"   305
  AB2 G   22   AIH22S   7.5"   385
  AB2 G   26   AIH22S   5.5"   401
  AB2 DS   22   AID22S   Full Double   625
  AB2 DS   26   AID22S   Full Double   725

VIDEO
   If you wonder how loud and what it looks like when one shoots AeroBolt II, here is a video provided by a new customer shooting his AeroBolt II 100 yards under 15 miles breeze and he has shot AeroBolt II for only 3 days.

AeroBolt II-200 24" out of Scorpyd Ventilator 150 at 366 fps with 15-25 mph cross wind at 100 yards with Hartcraft Trophy 1 broadhead

AeroBolt II-200 24" out of Scorpyd Ventilator 150 at 366 fps with 15-25 mph cross wind at 100 yards with Smoke Ramcat 100 broadhead

Label for AeroBolt II - 200 and AeroBolt II Dragon Slayer

AeroBolt II-200 (3-arrow)
AeroBolt II-G (3-arrow)
AeroBolt II-Dragon Slayer (3-arrow)

WHY AeroBolt II IS PRICED AND BUILT IN THIS WAY?
    Most people will find that most crossbow arrows are performing quite well.  But why AeroBolt II is better than the other arrows? Why the price of AeroBolt II is significantly higher?  Why Firenock built AeroBolt II like this?  What are the reasons behind these questions?  You will understand and be convinced after reading the below: a short review of research and development of AeroBolt and its design and technologies.  Furthermore, with better understanding of AeroBolt II technologies, you should acquaint what you can expect and what you can achieve the most from shooting with AeroBolt.
    Back in 2009 when Jim Kempf of Scorpyd requested for a heavier spine crossbow bolt due to the introduction of the RDT165, the concept of AeroBolt was born.  AeroBolt I was first built with Gold Tip Laser II, Laser III, other Gold Tip shafts, and Gold Tip Series 22 insert.  At that time, AeroBolts were nothing more than a piece of Gold Tip shaft ( 0.298” OD) Laser II or Laser III glued with a Gold Tip Series 22 insert.  Aerobolt I gave Jim the arrow he needed at that time as this specification gave Aerobolt I a heavier resulting spine and lessened the issue of not locating the spine due to dual shaft construction.  During the test of Aerobolt I, interesting facts were discovered and these leaded us to develop new concepts, break through manufacturing processes, improved design and eventually resulted in 4 US Patents.

Development of never harden 2 part epoxy
    When the AeroBolt I was made, CA base glue was used to secure the system.  But after a few shots, like many had tried, the CA base glue just cracked and caused layer separation of the carbon.  This issue was worst when the arrow was shot repeatedly and particularly for arrows with lower spine.  After dissecting the shaft, it was found that the CA glue was indeed cracked and became powder leading to layer separation and the failure of CA glue allowed the arrow to flex more and resulted in more cracks.
    A variety of glues, Super Glue, CA GEL, 5 minutes, 10 minutes, and even 30 minutes epoxy were tested, but they all failed.  Through the tests, we found that glue had a higher flexibility after cured, better result could be achieved. These results coincided with the idea that glue failure was due to the flex of the arrow during launch which leaded to carbon layer separation, then resulted in inconsistent of spine and finally ended up with inconsistent arrow flight.
    After repeated testing, a rare, expensive 2 part epoxy was found to be ideal as the epoxy is considerable flexible even it is totally cured.  Furthermore, the epoxy allows close to 2 hours work time, but this epoxy has high cP (i.e. does not flow and spread well).  To encounter high cP while gluing an inner shaft (as long as 13”) into the main shaft, usual apply and spread method would not work. Thus a special gluing process was developed to achieve perfect gluing between the 2 shafts.

Development of ultra sound cleaning process
    After extensive testing, Firenock found that high quality glue only works when all components are perfectly clean (no dirt, carbon powder, oil etc).  To clean the components properly, Firenock custom made a tall and narrow dual transducer ultra sound cleaner and uses Acetone as a solvent at room temperature to clean the arrow shafts before gluing and assembling.

Development of AeroInsert-D/H (Double and Hybrid Insert)
    The inherent issue of using a Gold Tip series 22 insert was observed while we have started to build the AeroBolt.  Gold Tip insert was short and did not have a lot of gluing surface.  The result of small gluing surface caused arrow shaft to crack right behind the insert when the arrow was shot at an extreme angle.  With the understanding of this issue, Firenock made AeroInsert-D to solve the issues.  AeroInsert is not just a metal insert, it is a hybrid insert which it is a metal insert inserted into a carbon tube; this hybrid insert is then inserted into the crossbow arrow shaft.  Below are the features of Firenock AeroInsert-D/H:

  • Large gluing surface: As AeroInsert-D is long, it can provide larger gluing surface than conventional insert.  As the gluing surface is larger, force can distribute more evenly and thus less stress will be asserted to the arrow shaft.
  • Small run out: As AeroInsert-D end is added with a piece of carbon shaft (i.e. Hybrid Insert), run out would become nearly zero as the long length of hybrid insert would eliminate the run out after the Hybrid Insert is inserted completely into the arrow shaft.  In case of the Tac 15’s 26.25” long arrow, the Hybrid Insert can be as long as 5.5" and as long as 13.5".

Development of FACT (Firenock Arrow Concentric Technology)
    After long discussion with archery arrow expert like Randy White, Tim Gillingham, one issue is obvious but always overlooked, it is the issue of concentricity.  Concentricity is not only important in arrows, but in bow as well as between arrow and bow.  On the present market, according to Firenock research, there is not a crossbow arrow or arrow rest that can provide good enough concentricity to ensure accuracy of an arrow.  With AeroInsert D, Firenock believed that the insert to shaft concentricity has been addressed.  With AeroPoint / Traumahawk, the concentricity of the field point/broad head to Insert has been addressed.

Development of Self Harmonic Dampening AeroBolt
    What is Harmonic Dampening? Harmonic Dampening was first observed when AeroBolt I was being tested.  During the test, we observed that the oscillation of AeroBolt I stopped only after about 5-10 feet.  This observation was unusual as a general arrow would usually oscillate at least 20 yards.  In general, the lighter the spine and the longer the arrow, the more the arrow will oscillate and will take longer time to stop oscillating till the arrow goes into a full gyro spin (i.e. not oscillating).  Also from our tests, it was discovered that the heavier the material used to build the arrow, the arrow will oscillate more and the arrow will lose more energy in terms of KE as more mass is being moved.  For Aerobolt, Hybrid Insert changed the above as the spine of arrow shaft changed completely, you will find Aerobolt stop oscillating soon after shot and can fly straighter and more accurate than any other bolts.

Development of Professional Arrow Preparation System (PAPS)
    Locating spine of an arrow is important as it tells you how the arrow will oscillate when it is shot.  In general, most will use the RAM Spine finder machine, however RAM Spine finder machine takes too long to spine an arrow and it is not reliable.  Thus Firenock built PAPS.  PAPS is a easy to use tool, you can find the softest side of natural spine of an arrow easily within 5 seconds.  We believe the softest side of natural spine is more important than the hardest side as an arrow will flex towards it softest side when it is launched (i.e. an arrow will flex towards the lowest resistance side).  Meanwhile, the hardest side only gives an indication of the hardest spine rating which it is not critical for arrow accuracy.  With PAPS, repeated accurate shooting among a bundle of Aerobolts without tuning is made possible.

Using Aerovane to Lift instead of using drag to spin
    AeroBolt uses Aerovane as its standard vanes.  Aerovane is using Aerodynamics to create spin instead of using drag (typical vanes use drag to cause the arrow to spin).  Due to using drag to spin, a lot of archers prefers to use a much heavier field point and/or broadhead as heavier field point can compensate the drag caused by typical vanes.  With this heavy setting, the front heavier point will be the dominant force to drag down the arrow and the vanes the back will stabilize the arrow from the drop and force air passing the vanes causing spin.  This also explains why some arrows need heavy FOC (Front of Center) in order to fly right.
    For Aerobolt with Aerovane, Aerovane is using lift to spin the arrow, not using drag to spin the arrow.  The working principle of Aerovane is just like an airplane wing; air moves at different speed above and below the vane surface due to the unique shape of Aerovane and thus creates lift.  The use of lift explains why an arrow equipped with Aerovane does not need heavy FOC in order to fly true.  By not needing a heavy FOC, the hang time of an archery projectile will be significantly increased.  Case in point, an identical archery projectile in weight when fletched with Aerovane II leaving the bow at 380 fps will have the same flight characteristics of an arrow fletched with typical vanes at 2.5 degree offset shooting at 420 fps.

Using Gluing instead of mechanical way to secure insert
    As the front end of the arrow will encounter extreme amount of force and vibration in all unpredictable direction upon impact, mechanical insert will focus the force and vibration upon impact and can damage the shaft inner surface.  For safety and reliability, spreading force over a large surface is the best way to resolve this problem, thus Firenock developed Hybrid Insert System, which our Hybrid Insert is long, made of carbon, protected by Metal AeroInsert on the front end and the Hybrid Insert system is glued into the arrow and thus impact force and vibration can be relieved upon impact.

Spine Indexing and Matching
    In order to allow archer to shoot Aerobolt with repeated accuracy, Firenock spine indexed and made Aerobolt within +/- 3 grain to ensure every Aerobolt will behave / shoot the same.

From the above, you should understand why AeroBolt can oscillate less, fly straighter and reach long distance than any other bolts and why Aerobolt can have less FOC as it is using lift instead of drag to spin arrow.
In summary, the combination of Self Concentric Technology, Hybrid Insert System and Aerovane make AeroBolt oscillating less, stabilizing itself faster and achieving gyro spin faster than any other bolts in which achieving gyro spin means less energy is lost and energy can be transferred efficiently to achieve a flatter, more accurate and more powerful shot.