Edge Break

The sharp edges of most precision machined surface are “broken” through a process called “edge break.” Edge break is accomplished by rounding off the corner, or by machining a flat “chamfer” to reduce the sharpness of the edge. The process is intended to ensure part longevity, safe handling, and proper performance.

Edge break serves several purposes depending on the application. Radiused and chamfered edges limit possible fracture points for components that are subject to high stresses or loads. Where component edges may effect air flow, such as turbine blades and nozzles, tight edge break tolerances ensure proper aerodynamic performance. Chamfers may also be added to fasteners to ensure that they do not protrude from shafts or casings. Lastly, in all of these cases, edge breaking reduces injuries from sharp edges and burrs, both in the production environment and in the field. 

Stylus-based profilers can also struggle to measure over sharp edges without breaking the stylus tip. The stylus profiler’s limited vertical range may prevent it from being able to measure large chamfers on machined holes. Add in the technology’s susceptibility to vibration, and it’s clear how this “fast” method can often take more than 30 minutes of setup and scan time to achieve a single high-quality trace.

Other methods, such as laser-based gage guns, provide some shop-floor capability for edge break and chamfer measurements, but only over a single line. Alignment errors persist, and low resolution means they cannot measure fine geometries. Material finish, reflectivity and slope can also affect measurement results.

3D measurement provides accurate, repeatable edge break analysis

4D InSpec is a handheld, 3D measurement device that uses polarized structured light for rapid, simple, shop-floor measurement of edge break, chamfer angles, and other precision part geometries.  Accuracy, repeatability, reproducibility, and durability make the 4D InSpec the right tool for measuring edge break in shop-floor environments.

The strength of this, you can see by picturing a measurement that behaves like the illustration below. By using planes connected in 3D to represent the chamfer and joining sides, the essential parameters become independent of orientation of the gauge–all profiles are calculated in respect to the direction of the planes.

How edge-break measurement works

The handheld 4D InSpec can be aimed directly at the edge to be measured. Alignment is trivial because it’s easy to get the correct distance, and angle variability is robust. The system provides immediate feedback to generate highly repeatable, 3D measurements of the entire edge—not just a single trace.

Having a 3D measurement alone is insufficient to analyze edge break, however. The software included with the 4D InSpec aligns plane and cylinder fits to the geometry, rather than treating the measurement as a series of adjacent traces. This method compensates for tilt and rotation of the instrument with respect to the multiple surfaces being measured.

Using this method, measurement results are based on the 3D plane and cylinder fits, rather than a single trace or even an average across multiple traces. This method greatly improves accuracy, records the results numerically, and makes for much more repeatable measurements.

Stylus-based profilers can also struggle to measure over sharp edges without breaking the stylus tip. The stylus profiler’s limited vertical range may prevent it from being able to measure large chamfers on machined holes. Add in the technology’s susceptibility to vibration, and it’s clear how this “fast” method can often take more than 30 minutes of setup and scan time to achieve a single high-quality trace.

Other methods, such as laser-based gage guns, provide some shop-floor capability for edge break and chamfer measurements, but only over a single line. Alignment errors persist, and low resolution means they cannot measure fine geometries. Material finish, reflectivity and slope can also affect measurement results.

3D measurement provides accurate, repeatable edge break analysis

4D InSpec is a handheld, 3D measurement device that uses polarized structured light for rapid, simple, shop-floor measurement of edge break, chamfer angles, and other precision part geometries.  Accuracy, repeatability, reproducibility, and durability make the 4D InSpec the right tool for measuring edge break in shop-floor environments.

The strength of this, you can see by picturing a measurement that behaves like the illustration below. By using planes connected in 3D to represent the chamfer and joining sides, the essential parameters become independent of orientation of the gauge–all profiles are calculated in respect to the direction of the planes.

How edge-break measurement works

The handheld 4D InSpec can be aimed directly at the edge to be measured. Alignment is trivial because it’s easy to get the correct distance, and angle variability is robust. The system provides immediate feedback to generate highly repeatable, 3D measurements of the entire edge—not just a single trace.

Having a 3D measurement alone is insufficient to analyze edge break, however. The software included with the 4D InSpec aligns plane and cylinder fits to the geometry, rather than treating the measurement as a series of adjacent traces. This method compensates for tilt and rotation of the instrument with respect to the multiple surfaces being measured.

Using this method, measurement results are based on the 3D plane and cylinder fits, rather than a single trace or even an average across multiple traces. This method greatly improves accuracy, records the results numerically, and makes for much more repeatable measurements.