Components | Restorative Lift

Test Equipment

The restorative-lift protocol was run on both the standard-speed and high-speed component test sets. The two sets share every piece of equipment listed below; only the bow setup differs.

• Bow: Hoyt AX-3 33, run in two configurations:
  • 28″ draw length, 70 lb draw weight for the standard-speed vane test. (~290fps)
  • 29″ draw length, 80 lb draw weight for the high-speed vane test. (~325fps)
• Indoor facility: Easton Salt Lake Archery Center (Easton Foundation), Salt Lake City, UT.
• Shooter: Easton Archery's custom shooting machine, used to ensure precise, repeatable shots and eliminate shooter variability.
• Mass measurement: Last Chance Archery Pro Grain Scale 2.0. Every arrow was weighed and per-build averages were used in downstream calculations.
• Fletching jigs: a left-helical Bitzenburger jig, a right-helical Bitzenburger jig, and an Arizona E-Z Fletch were used to fletch arrows across three deliberate helical conditions per vane.
• Environmental measurement: Kestrel 5700 Elite. Density altitude averaged 5670 ft across the test sessions.

Overview

Restorative lift refers to the aerodynamic forces that help stabilize and re-align an arrow's flight path following a disturbance or initial misalignment (e.g. an out-of-tune bow or torqued shot). Direct measurement of aerodynamic lift in free flight is extremely challenging, so this study uses controlled horizontal misalignment to quantify each build's ability to recover (or not recover) from an imposed angular deviation. The result is a practical real-world proxy for restorative lift based on observed group position at distance.

Lateral Torque Setup

For this protocol the bow was set up with a consistent lateral torque about its vertical axis, applied via a pulley system attached to the shooting machine. A 1.25 lb weight hangs through the pulley and pulls horizontally on the bow at a point 6″ from the stabilizer bushing, rotating the bow roughly 2° and producing a paper tear of approximately 1″ nock-right at 15 ft. Every torqued shot in 2026 sees the same induced launch error.

Arrows and Points

For each build, the following arrows were shot through the torqued setup at the 70-yard target:

• 6 Gold Tip field points
• 6 Iron Will Wide fixed-blade broadheads

The 2026 protocol increases the per-group sample size to n = 6 for both field-point and broadhead conditions (vs. n = 4 in 2025). Larger per-group sample sizes give the per-build mean point of impact (and its 95% confidence interval) more statistical power for the lift-proxy comparison described below.

Photo Capture

Every group was photographed at the target with a Panasonic Lumix S5IIX paired with a 70 mm lens, mounted in a consistent position relative to the target between sessions. Each frame includes the floor / tape / pin / background reference annotations described in the photo-analysis pipeline so the image can be levelled, scaled, and origin-corrected to a common inch-space coordinate system.

The full annotation, coordinate-transform, calibration and statistics workflow is documented separately on Photo Capture & Analysis; that page is the canonical source for how each impact photograph is converted into the (x, y) coordinates and 95% t-distribution confidence intervals used here.

Lift Proxy (New in 2026)

What we did

For each build (vane × fletch helical × shaft) the shooting machine fired 6 torqued Gold Tip field points and 6 torqued Iron Will Wide broadheads through the same induced lateral bow torque, at the same target, on the same arrows. We then cycled through the full vane lineup and repeated. On every build the launch disturbance is the same; what changes between the two groups on a build is only the point, and what changes across builds is only the vane.

What we measure

The 2026 restorative-lift proxy is the lateral drift between the torqued broadhead group and the torqued field-point group on the same build:

That difference is a real-world readout of how much further the broadhead-tipped arrow drifted than the field-point arrow off the same launch error.

What it tells us about the vane: aerodynamic jump

Aerodynamic jump is the angular deviation a fin-stabilized projectile picks up while it yaws back into alignment after a disturbance at launch. While the arrow is yawed, the aerodynamic normal force at the tail pushes the center of gravity sideways; by the time yaw is damped out, the velocity vector is bent off the bore line and the arrow flies down a new, offset path. A faster-recovering arrow spends less time yawed, so its CG is redirected less, so it lands closer to where the clean shot would have. Field points generate very little of this jump because their shape is symmetric around the arrow shaft; broadhead blades sit forward of the CG and amplify the jump-producing forces. The drift between the field-point and broadhead groups on a single build is therefore a direct in-flight readout of how much jump-amplification the vane was able to suppress.

What it tells us about the vane: static margin

Static margin is the distance between the arrow's center of pressure (CP) and its center of gravity (CG); larger static margin means a stiffer restoring moment and faster yaw recovery. Across the vane lineup on the same shaft, point, insert, and nock the arrow mass distribution is held essentially constant (vane mass is small), so the CG barely moves between vanes. What does change is the tail-end aerodynamic loading, which is exactly what sets CP. Each vane is therefore a controlled change in static margin with CG held fixed, and the field-point vs. broadhead drift across builds is a clean ranking of how quickly each vane recovers from the same broadhead-induced disturbance. Lower drift means a vane that pushes CP further aft, gives a larger static margin, recovers faster, and produces less aerodynamic jump.

Statistics

95% confidence intervals on the per-group mean point of impact are computed using the t-distribution (df = n − 1) on the transformed inch-space coordinates. The CI on the drift metric is the propagated combination of the two contributing groups' x-position CIs (clamped at 0 because the metric is reported as an absolute value). See the Photo Capture & Analysis page for the full t-distribution recipe.