Knowledge Base Topic · KB-S05

CNC Accuracy, Calibration and Inspection

Measure repeatability, squareness, reversal, scale, tram, tool length and finished parts before correcting them.

Structured learning collection

10 practical guides

Open one guide at a time or follow the numbered sequence.

10 guides

Three targets comparing accuracy, repeatability and both together

KB-041

CNC Accuracy vs Repeatability: Why the Difference Matters

Separate closeness to a target from consistency between repeated results before adjusting calibration, offsets or machining strategy.

Parallelogram test shape with two measured diagonals

KB-042

How to Test CNC Gantry Squareness with Diagonals and Test Cuts

Use diagonal comparisons and machined geometry to distinguish XY squareness error from tool diameter, scale and measurement problems.

Axis arrows reversing across a visible lost-motion gap

KB-043

CNC Backlash and Lost Motion: Testing Direction Reversals

Recognize reversal-dependent position error, separate mechanical lost motion from scale error and evaluate correction without hiding wear.

Commanded axis distance compared with measured distance

KB-044

CNC Axis Scale Calibration with Commanded and Measured Travel

Calibrate axis distance from a long controlled move while avoiding tool diameter, backlash, instrument and one-point compensation errors.

Indicator arm sweeping left and right across a table

KB-045

CNC Spindle Tram: Reading an Indicator Sweep Across the Table

Understand front-back and left-right tram, indicator sweep geometry, table reference and the finish patterns caused by angular misalignment.

Three cutters of different lengths ending at one Z reference

KB-046

CNC Tool Length Offsets: Measuring and Applying Tool Tip Position

Understand how tool-length measurement maps different physical cutters to a consistent programmed Z reference without confusing work and tool offsets.

Touch probe approaching a known workpiece edge

KB-047

Using a CNC Probe to Find an Edge and Set a Work Offset

Plan probe direction, clearance, trigger behavior, stylus radius and result handling before using contact to establish a CNC work reference.

Calibration coupon containing rectangle, hole and diagonal features

KB-048

Design a CNC Calibration Coupon That Reveals Errors

Combine outside dimensions, pockets, holes, diagonals and repeated features in one traceable coupon without confusing tool and machine effects.

Outside and inside CNC features measured with different contacts

KB-049

How to Measure CNC-Routed Parts Correctly

Match calipers, micrometers, indicators and gauges to the feature while controlling burrs, contact force, temperature and datum choice.

Four dimensional error patterns labeled offset, scale, taper and reversal

KB-050

CNC Dimensional Errors: Diagnose the Pattern First

Diagnose offset, proportional, reversal, taper and location-dependent errors before changing drawings, cutter values or controller compensation.