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New article published in Archery Focus Magazine (TwisterNock)

Khosro/Jeff Hajari
Khosro/Jeff Hajari

The document summarizes tests conducted to evaluate the performance of a new product called the TwisterNock compared to standard pin nocks. The tests showed that at 20 yards, groupings were similar, but at 40 yards the TwisterNock group was 3.5 inches higher and had a smaller grouping size. Broadhead tests also showed the TwisterNock penetrated the target 4 inches deeper and had a smaller grouping. The informal tests suggested the TwisterNock helps stabilize the arrow in flight, leading to improved accuracy and more energy transferred to the target. The results indicated the TwisterNock is an effective design that could benefit hunters.

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We thought the readers of Archery Focus might like to see the lengths we go to to test a new product under development, when we dont have an expensive lab to test things in. The product under development here is the TwisterNock which we think will help hunters get better grouping and more penetration out of their current rigs. The idea of TwisterNock came to me while I was hunting. I still remember my excitement when a deer walked in 20 yards from my tree stand. I took a shot and my arrow hit the deer in the leg. It was an awe- full feeling wounding an animal and not being able to harvest it. I realized that my fletching caught a tree branch in its path and deflected my arrow. Right there sitting in my tree stand, I started thinking of ways to stabilize the arrow and minimizing the need for fletching. I created many designs for a mechanical arrow nock (TwisterNock); some are more complicat- ed and offer more features to archers. Most of them use a spring. Some need to be cocked. For my first production TwisterNock, I chose a design that is the most versatile, and could be used with most common bows, including traditional bows. The design basically consists of two parts, the nock (plunger) and a housing for it. They move relative to one other. There are some guide channels and guide pins that generate rotation when the nock and the housing move. The nock has to be cocked prior to the shot. There is a spring that moves the nock from cocked position when pressure is applied to the nock, that is when it is shot, and then the arrow starts to rotate while still on the bow string. This rotation helps the arrow spine reaction and reduces the arrow flex resulting in better accuracy and more kinetic energy being transferred to the arrow. The Product Testing These tests were conducted on April 7, 2013 to eval- uate the arrow flight patterns using our Mechanical Arrow Nocks (TwisterNock) vs. Standard (Regular) Pin Nocks. We hoped to show increased accuracy, and 14 Archery Focus A Product Comparison: TwisterNocks vs. Pin Nocks by Jeff Hajari
Archery Focus 15 improvement in spine recovery due to the increased recovery time the TwisterNock provides. Equipment Used For This Test Spot Hogg Hooter Shooter Bow ( 2008 BowTech Tribute) with hunting set up 55# draw weight. Multi pin sight(Vital Gear) Drop away rest (Trophy Taker) 6 stabilizer Arrows used Gold Tip X Cutter Pro Arrow weight of 383 grain complete with fletch- ing, Pin Nock and Pin Bushing Arrow Weight of 382 grain with TwisterNock 2 Blazer vanes TwisterNock (Model A1) Nikon Archers Choice rangefinder (for setting target distances) Chronograph (F-1 Shooting Chrony) Testing Process Used The test was done to check the flight pattern and grouping of the arrows with the different nock assem- blies installed. No fine tuning was done to the bow to increase accuracy. This test was performed using three(3) arrows labeled A, B, and C. The arrows were fletched at a 1属 offset using the Bohning Tower Fletching Jig. All tests were performed with the different nock assemblies at 20 and 40 yards. The results were logged and the arrows were then re-fletched at 3属 and the tests repeated. Arrow Speed Testing For this test the chronograph was set at 1 arrow length from the riser, and in front of the bow. All arrows where shot from the same exact position. All speeds listed are in feet per second (fps). Test Arrow A B C 1属 fletch/ Regular Nock 262.1 262.0 261.6 1属 fletch/ TwisterNock 262.7 263.0 262.5 3属 fletch/ Regular Nock 258.5 261.4 262.0 3属 fletch/ TwisterNock 259.5 261.6 264.2 Grouping at 20 yards (with 1属 fletching) Groups of three arrows were shot with both Regular Nock and TwisterNock (see photo next page). At 20 yards, the groupings were the same for both nock assemblies. The TwisterNock did hit slightly higher, but it was too small to measure properly. (A higher hit point indicates the arrow received more energy from the bow.)
Archery Focus Grouping at 40 yards (with 1属 fletching) The three arrow group with the Regular Nock hit 1 below the center with a group size (largest extent) of 112. The three arrow group with the TwisterNock hit 212 above center with a group size of 34. Note The difference in the arrow trajectory at 40 yards showed a 312 difference in the height of the group centers when comparing the Regular Nock to the TwisterNock. Grouping at 20 yards (with 3属 fletching) The three arrow group with Regular Nock hit 12 bellow the center with the group averaging 114 in size. The three arrow group with TwisterNock hit 1 above the center. The group size was 1 34 in a vertical direction only. Note The difference in group center height was 112. TwisterNock arrows impacted higher. Grouping at 40 yards (with 3属 fletching) The three arrow group with the Regular Nock hit 1 34 below the center mark with a 2 grouping. The three arrow group with the TwisterNock hit 78 above the center resulting in a 18 grouping. Note The difference in arrow trajectory at 40 yard between Regular Nock and TwisterNock is 258. Arrows fitted with the TwisterNock impacted higher again. Grouping and Penetration at 20 yards (with broadheads) We decided the results were so good we would go ahead and check performance with a broad head fit- ted. We took a single arrow: 350 grain cut to 30 with a straightness of 賊6 thousandths of an inch. We used a Twister vane sleeve for a G5 Montec broadhead (100 gr, three blade) and shot at a block target. We shot the same arrow, fitted with a regular nock, three(3) times into block target.Then we changed the nock for TwisterNock and shot that arrow three(3) times. We measured the penetration of all shots. The Results The Regular Nock group was 258 while the TwisterNock group was 118. The average penetration of the TwisterNock shots was 4 greater than the Regular Nock arrows. Conclusion While we dont have a fancy testing lab we managed to create some tests that were more similar to what hunters experience out if the field that showed that we were on the right path in the development of our new TwisterNock. 16

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New article published in Archery Focus Magazine (TwisterNock)

  • 1. We thought the readers of Archery Focus might like to see the lengths we go to to test a new product under development, when we dont have an expensive lab to test things in. The product under development here is the TwisterNock which we think will help hunters get better grouping and more penetration out of their current rigs. The idea of TwisterNock came to me while I was hunting. I still remember my excitement when a deer walked in 20 yards from my tree stand. I took a shot and my arrow hit the deer in the leg. It was an awe- full feeling wounding an animal and not being able to harvest it. I realized that my fletching caught a tree branch in its path and deflected my arrow. Right there sitting in my tree stand, I started thinking of ways to stabilize the arrow and minimizing the need for fletching. I created many designs for a mechanical arrow nock (TwisterNock); some are more complicat- ed and offer more features to archers. Most of them use a spring. Some need to be cocked. For my first production TwisterNock, I chose a design that is the most versatile, and could be used with most common bows, including traditional bows. The design basically consists of two parts, the nock (plunger) and a housing for it. They move relative to one other. There are some guide channels and guide pins that generate rotation when the nock and the housing move. The nock has to be cocked prior to the shot. There is a spring that moves the nock from cocked position when pressure is applied to the nock, that is when it is shot, and then the arrow starts to rotate while still on the bow string. This rotation helps the arrow spine reaction and reduces the arrow flex resulting in better accuracy and more kinetic energy being transferred to the arrow. The Product Testing These tests were conducted on April 7, 2013 to eval- uate the arrow flight patterns using our Mechanical Arrow Nocks (TwisterNock) vs. Standard (Regular) Pin Nocks. We hoped to show increased accuracy, and 14 Archery Focus A Product Comparison: TwisterNocks vs. Pin Nocks by Jeff Hajari
  • 2. Archery Focus 15 improvement in spine recovery due to the increased recovery time the TwisterNock provides. Equipment Used For This Test Spot Hogg Hooter Shooter Bow ( 2008 BowTech Tribute) with hunting set up 55# draw weight. Multi pin sight(Vital Gear) Drop away rest (Trophy Taker) 6 stabilizer Arrows used Gold Tip X Cutter Pro Arrow weight of 383 grain complete with fletch- ing, Pin Nock and Pin Bushing Arrow Weight of 382 grain with TwisterNock 2 Blazer vanes TwisterNock (Model A1) Nikon Archers Choice rangefinder (for setting target distances) Chronograph (F-1 Shooting Chrony) Testing Process Used The test was done to check the flight pattern and grouping of the arrows with the different nock assem- blies installed. No fine tuning was done to the bow to increase accuracy. This test was performed using three(3) arrows labeled A, B, and C. The arrows were fletched at a 1属 offset using the Bohning Tower Fletching Jig. All tests were performed with the different nock assemblies at 20 and 40 yards. The results were logged and the arrows were then re-fletched at 3属 and the tests repeated. Arrow Speed Testing For this test the chronograph was set at 1 arrow length from the riser, and in front of the bow. All arrows where shot from the same exact position. All speeds listed are in feet per second (fps). Test Arrow A B C 1属 fletch/ Regular Nock 262.1 262.0 261.6 1属 fletch/ TwisterNock 262.7 263.0 262.5 3属 fletch/ Regular Nock 258.5 261.4 262.0 3属 fletch/ TwisterNock 259.5 261.6 264.2 Grouping at 20 yards (with 1属 fletching) Groups of three arrows were shot with both Regular Nock and TwisterNock (see photo next page). At 20 yards, the groupings were the same for both nock assemblies. The TwisterNock did hit slightly higher, but it was too small to measure properly. (A higher hit point indicates the arrow received more energy from the bow.)
  • 3. Archery Focus Grouping at 40 yards (with 1属 fletching) The three arrow group with the Regular Nock hit 1 below the center with a group size (largest extent) of 112. The three arrow group with the TwisterNock hit 212 above center with a group size of 34. Note The difference in the arrow trajectory at 40 yards showed a 312 difference in the height of the group centers when comparing the Regular Nock to the TwisterNock. Grouping at 20 yards (with 3属 fletching) The three arrow group with Regular Nock hit 12 bellow the center with the group averaging 114 in size. The three arrow group with TwisterNock hit 1 above the center. The group size was 1 34 in a vertical direction only. Note The difference in group center height was 112. TwisterNock arrows impacted higher. Grouping at 40 yards (with 3属 fletching) The three arrow group with the Regular Nock hit 1 34 below the center mark with a 2 grouping. The three arrow group with the TwisterNock hit 78 above the center resulting in a 18 grouping. Note The difference in arrow trajectory at 40 yard between Regular Nock and TwisterNock is 258. Arrows fitted with the TwisterNock impacted higher again. Grouping and Penetration at 20 yards (with broadheads) We decided the results were so good we would go ahead and check performance with a broad head fit- ted. We took a single arrow: 350 grain cut to 30 with a straightness of 賊6 thousandths of an inch. We used a Twister vane sleeve for a G5 Montec broadhead (100 gr, three blade) and shot at a block target. We shot the same arrow, fitted with a regular nock, three(3) times into block target.Then we changed the nock for TwisterNock and shot that arrow three(3) times. We measured the penetration of all shots. The Results The Regular Nock group was 258 while the TwisterNock group was 118. The average penetration of the TwisterNock shots was 4 greater than the Regular Nock arrows. Conclusion While we dont have a fancy testing lab we managed to create some tests that were more similar to what hunters experience out if the field that showed that we were on the right path in the development of our new TwisterNock. 16