CNC Testing and Calibration Explained

CNC calibration is the process of verifying and adjusting machine tool accuracy through precision measurement of linear axes, rotary components, and geometric relationships. It's important because even new machines can have shipping damage or installation errors, and all machines experience wear over time. Proper calibration ensures parts are machined to specification, reduces scrap, prevents unexpected downtime, and provides documented proof that equipment performs as promised.

Calibration frequency depends on machine usage, part tolerances, and production requirements. New machines should be calibrated before warranty expiration to document baseline performance. Production machines typically benefit from annual calibration, though high-precision or high-volume operations may require more frequent verification. Ballbar testing can be performed quarterly as a quick health check between comprehensive calibrations.

Laser interferometry uses wavelength of light to measure machine axis positioning with extreme precision. Sarkinen Calibrating's Renishaw system achieves accuracy to 1.0 part per million (one millionth of an inch per inch), which exceeds the required 10:1 ratio for proper calibration. All measurements are traceable to NIST and International Standards, providing documented proof of machine accuracy for quality systems and customer audits.

Ballbar testing uses a telescoping bar with precision sensors to trace circular paths and evaluate machine performance. The Renishaw QC20-W wireless ballbar quickly identifies backlash, servo mismatch, axis reversal errors, squareness problems, and overall circularity issues. It's one of the fastest ways to assess machine health, validate recent service work, and support maintenance planning with minimal production disruption.

Yes, and this is highly recommended. Shipping and installation often introduce alignment errors or hidden damage that may not be immediately apparent. Calibrating new machines while under warranty provides documented evidence if the machine doesn't meet manufacturer specifications, allowing you to address issues before the warranty expires and ensuring you receive the accuracy you paid for.

Sarkinen Calibrating primarily serves Portland OR and SW Washington with faster response times than out-of-area providers. We also have capabilities to help customers outside this primary service area in Oregon, Washington, Northern California, and Idaho. Our local presence minimizes scheduling delays and reduces downtime for calibration work.

Calibration time varies by machine size, number of axes, and scope of work. Ballbar testing can be completed in a few hours, while comprehensive laser interferometer calibration of all axes may take one to two days. We work to minimize production disruption and can often schedule work during planned downtime or off-shifts to accommodate your production schedule.

You receive comprehensive reports showing measurement data, identified issues, before-and-after comparisons, and specific recommendations. All measurements are NIST-traceable, providing documented proof for quality management systems, customer audits, and ISO compliance. Reports clearly explain how any detected errors affect part accuracy and what corrective actions will restore optimal performance.