CNC Probe Repeatability Comparison: Which Mounting Method Delivers the Best Accuracy?

In high-precision machining, every micron matters. That’s why we carried out a practical test to compare the measurement repeatability of the DIG3D.R rotary CNC probe using three different mounting methods commonly used in CNC environments.

🔬 Tested Mounting Methods:

1. • Fixed rotary probe (DIG3D.R) – rigidly mounted to the Z-axis

   • ISO20 tool holder – used for comfortable tool exchange or in automatic tool changers (ATC)

   • Direct spindle insertion – probe manually inserted into the collet before each measurement

Each approach has its own impact on precision, setup time, and ease of use. Our goal was to find the most effective combination of performance and practicality.

✅ Measurement Results

For each setup, we performed 10 full measurement cycles by probing the center of a hole. After every cycle, the absolute coordinates were recorded, and the total deviation in X and Y axes was calculated.

The results clearly show that the DIG3D.R rotary probe offers the best balance of speed and precision, especially due to its fully integrated mounting and automatic actuation.

⚙️ What Affects Repeatability?

• • Mechanical rigidity of the machine – stable and backlash-free axis movement is key

  • Mounting method – each method introduces different levels of mechanical variation

  • Collet quality – low-quality collets can add up to 0.1 mm in deviation

  • Automation level – software-controlled probing eliminates human error and saves time

🏁 Conclusion

If you’re looking for the most accurate and efficient way to perform probing cycles on your CNC machine, DIG3D.R is the clear winner.
Its design eliminates the need for probe insertion or tool changes and allows for fully automated measurement routines—controlled directly from your CNC program.
With repeatability as low as 3 microns and setup time under 2 seconds, this solution delivers performance you can rely on.