CNC knowledge base
Practical CNC preview and file guides
Use these field-oriented references to interpret machining files, test assumptions and compare programmed motion with the expected finished part. Each guide explains what the source data can prove, what may be missing and which checks still belong at the machine.
Work through a downloadable example
Compare a complete NC file with calculated dimensions, a reference drawing and block-by-block explanations. Each file is small enough to inspect by hand.
A 6 mm cutter: measure a straight channel
Download a short NC example and verify a 6 mm-wide, 4 mm-deep channel using the cutter radius and programmed endpoints.
Four blind holes from one G81 cycle
Download a four-hole NC program and check modal G81 drilling, 8 mm diameter, 12 mm depth and 80 x 40 mm center spacing.
Why a closed contour leaves a solid center
Download a rectangular contour example and compare its 6 mm swept groove with the 74 x 34 mm uncut central island.
Start with the fundamentals
Core concepts for any supported machining format.
CNC file formats explained
Compare NC, TAP, NGC, MPR, HOP, PLT, XML and NCD data before previewing a program.
How to read a CNC toolpath
Understand tool centerlines, removed volume, drilling, channels and density.
CNC Z zero and cutting depth
Identify top, bottom and positive-Z conventions without confusing travel with cutting.
Cutter diameter and compensation
Check centerline, inside and outside processing and the true width of a selected cutter.
MPR and HOP troubleshooting
Review panel variables, repeated operations, machining faces and missing tool data.
CNC preview verification checklist
Use a repeatable sequence before accepting a visual result or machining a part.
Troubleshoot specific operations
Focused references built around common preview failures.
G81, G82 and G83 drilling cycles explained
Understand G81, G82 and G83 CNC drilling cycles, retract planes, peck depth and the checks needed for an accurate hole preview.
Horizontal holes and edge drilling in CNC previews
Learn how edge, side and horizontal drilling operations use face, direction, center height, diameter and depth data.
How to preview PLT CNC files with depth and thickness
Understand why PLT machining paths often need user-supplied cutter diameter, cutting depth and stock thickness.
CNC simulation density, accuracy and performance
Choose an appropriate CNC solid simulation density and understand why large cutters, long files and fine grids affect processing time.
Reading CNC technical drawings and hole dimensions
Learn how a browser-generated CNC technical drawing should show overall size, hole locations, channels, notches and selected dimensions.
Height maps versus solid CNC simulation
Compare displacement height maps with solid CNC previews and learn where each method works for relief paths, holes and edge machining.