Gyraline Accuracy VS Hunter Hawkeye:
Why should you trust an iPhone and a 3D printed adapter? The proof is in the data
Gyraline
VS.
Hunter Hawkeye
Why trust an iPhone and a 3D printed adapter? Great question! The proof is in the data
The study at a glance:
10
Number
of Trials
0.01°
Total Toe
Avg Diff
0.07°
Camber
Avg Diff
Production DIY Gyraliner
Adapter Used
iPhone 13
Device Used
Executive Summary
In the automotive industry, achieving precise and repeatable wheel alignment is critical for optimizing vehicle performance, stability, and tire wear. Traditional methods of wheel alignment measurement can be time consuming and require expensive stationary equipment.
This page introduces and analyzes the Gyraline Platform, an innovative handheld tool designed to quickly measure wheel alignments in the field. We will specifically look at the similarity and precision of Gyraline’s camber and total toe measurements when compared to a Hunter Alignment Machine, the current industry standard alignment machine.
Through rigorous testing and analysis, the precision of the Gyraline Platform has been characterized by a measurement range of +/- 0.020° at a 99% confidence interval for total toe measurements. This precision is well within the range of the most stringent industry dictated critical resolution of +/- 0.050°, and is similar to the tools currently trusted in the industry.
Introduction
Wheel alignment is an essential process that ensures an automobile’s wheels are parallel to the vehicle’s centerline, or offset slightly within a specified range. Wheel alignment alters the vehicle’s handling characteristics and has a substantial effect on tire wear.
A wheel alignment can be modified by normal component wear, such as the natural wear on bushings, or inadvertently by impacts, such as from potholes and curbs. In order to correct out of range wheel alignment, a vehicle must have the alignment measured. A user then must adjust the suspension via the vehicle’s onboard adjustment hardware.
Purpose of Study
Traditionally, wheel alignment measurements are conducted on machines which include a vehicle lift, four image or laser targets, and a large camera assembly. These devices are large and stationary, commonly taking up an entire repair bay, and do not allow for mobile operation. Further, they have extended setup times to check each vehicle’s alignment. Gyraline is a newly developed mobile alignment platform that uses a specially cased handheld device and its onboard sensors.
This study looks to measure the repeatability and precision for total toe and camber of the Gyraline Platform alongside that of a Hunter Alignment Machine, the current industry standard wheel alignment machine.
Methodology and Testing
The vehicle of choice for this testing was a 2023 vehicle with ~7,900 miles on the odometer with no known issues.
The Hunter Alignment Machine tested herein is a Hunter Engineering Hawkeye laser alignment machine. It is owned and operated by an OEM dealership, recently calibrated and is a typical example. The Hunter Alignment Machine sensors were removed in between alignment checks and new rolling compensations were performed for each test.
The Gyraline Platform tested herein is the public release of Gyraline DIY 2.00 running on a Gyraline calibrated Apple iPhone 13 Pro. The device was installed in an off the shelf production “Gyraliner DIY” which is the official Gyraline DIY phone encasement that allows for precise Gyraline DIY measurements.
Caster and Ackermann were not captured during this testing for the Hunter Wheel Alignment Machine and Gyraline DIY due to time constraints.
The test procedure was conducted as follows:
| Step | Procedure |
|---|---|
| 1 | Load vehicle onto the Hunter Alignment Machine rack |
| 2 | Raise machine into alignment position |
| 3 | Roll vehicle forward into specified position to capture rolling compensation |
| 4 | Install Hunter Alignment Machine sensors |
| 5 | Conduct rolling compensation per Hunter Alignment Machine interface |
| 6 | Center steering and print Hunter Alignment Machine measurement results |
| 7 | Remove Hunter Alignment Machine sensors but do not move the car |
| 8 | Measure front/rear total toe and camber with Gyraline DIY |
| 9 | Roll the vehicle back to Hunter Alignment Machine rolling compensation start |
| 10 | Repeat steps 3 - 9 until ten datasets are captured each |
Results
Total Toe
Averaged and corrected for one outlier, the Hunter Alignment Machine found the total toe on the front axle to be 0.36°. Gyraline DIY, averaged and corrected for one outliner, found the total toe on the front axle to be 0.35°.
Averaged and corrected for one outlier, the Hunter Alignment Machine found the total toe on the rear axle to be 0.35°. Gyraline DIY, averaged and corrected for one outliner, found the total toe on the rear axle to be 0.36°.
The Hunter Alignment Machine range for total toe measurements at a 99% confidence interval is +/- 0.016°.
Gyraline DIY’s range for total toe measurements at a 99% confidence interval is +/- 0.020°.
Camber
Averaged and corrected for one outlier, the Hunter Alignment Machine found the camber on the front left wheel to be -0.70°. Gyraline DIY, averaged and corrected for one outliner, found the camber on the front left wheel to be -0.76°.
Averaged and corrected for one outlier, the Hunter Alignment Machine found the camber on the front right wheel to be -0.77°. Gyraline DIY, averaged and corrected for one outliner, found the camber on the front right wheel to be -0.79°.
Averaged and corrected for one outlier, the Hunter machine found the camber on the rear left wheel to be -1.41°. Gyraline DIY, averaged and corrected for one outliner, found the camber on the rear left wheel to be -1.59°.
Averaged and corrected for one outlier, the Hunter machine found the camber on the rear right wheel to be -1.48°. Gyraline DIY, averaged and corrected for one outliner, found the camber on the rear right wheel to be -1.50°.
The Hunter Alignment Machine’s range for camber measurements at a 99% confidence interval is +/- 0.056°.Gyraline DIY’s range for camber measurements at a 99% confidence interval is +/- 0.105°.
Analysis
Comparing the data sets and results of the Hunter Alignment Machine and Gyraline DIY, we see that the Hunter Alignment Machine was slightly more precise than Gyraline DIY, but both measured the vehicle’s toe within a range of 0.05°, and camber within a range of 0.25° with a high degree of repeatability. Given the typical manufacturer specification range of 0.20° for toe and 1.00° for camber, Gyraline DIY is able to measure and display wheel alignment data with a high enough precision to determine whether a vehicle’s wheel alignment is within factory specification.
Further, comparing the values of the results we see that the Hunter Alignment Machine’s measurement for total toe front was 0.36° and Gyraline’s average value for total toe front was 0.35°. Similarly, the Hunter Alignment Machine’s measurement for total toe rear was 0.36° and Gyraline DIY average value for total toe rear was 0.35°. Thus, the Hunter Alignment Machine and Gyraline DIY produced measurement values overlapping within each other's range at a 99% confidence interval.
The reader should note that the true alignment of the test vehicle was unknown and neither the Hunter Alignment Machine nor the Gyraline Platform are able to provide a measurement that allows for a determination of the absolute accuracy of any measurement. Analysis of the data is focused on the range between measurements of each of the respective tools and to each other.
The source of the above statements can be found in the following tables.
Conclusion
Through rigorous testing and analysis, Gyraline DIY has been found to be nearly as precise as a Hunter Alignment Machine. While the Hunter Alignment Machine was slightly more precise than Gyraline DIY, both measured the vehicle’s toe within a range of 0.05°, and camber within a range of 0.25° with a high degree of repeatability. Given the typical manufacturer specification range of 0.20° for toe and 1.00° for camber, Gyraline DIY is able to measure and display wheel alignment data with a high enough precision to determine whether a vehicle’s wheel alignment is within factory specification. Further, this precision is well within the range of the most stringent industry dictated critical resolution of +/- 0.050° for toe.