Exploring CNC

A CNC router turns a digital model into a physical part. The question is whether you understand what's happening between the model and the cut, or you're just clicking "generate toolpath" and hoping.

This site documents an open-source CNC workflow from first principles: designing in FreeCAD, generating toolpaths, understanding the G-code that comes out the other end, and driving the machine with Universal Gcode Sender — not just how to follow a setup guide, but why the workflow is built the way it is.

Who This Is For

Anyone starting out with a hobbyist CNC router — a new build, a used machine, or a kit — who wants to actually understand the process instead of copying setup videos. No prior machining or CAD experience assumed.

Where Do You Start?

Articles are grouped into topics — the subjects of CNC work, like coordinate systems and toolpaths. Each article carries a difficulty tag (Beginner, Intermediate, Advanced) so you can gauge depth at a glance, but there's no paywall or tier to unlock — just start wherever your machine and your questions are.

• New to CNC?

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  Start at the very beginning — no prior knowledge assumed.

  Start with Axes and Coordinate Systems

• Staring at a generated file?

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  Learn the small vocabulary behind every G-code file.

  Start with Reading G-code

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Topics

Machine Foundations

• Axes and Coordinate Systems — What X, Y, and Z actually mean, and why the machine needs two separate zeros

Reading G-code

• Reading G-code — The small vocabulary behind every generated file, and why "modal" state matters

CAD/CAM Workflow, Machine Control, Materials & Cutting, Maintenance & Calibration (coming soon)

Part of the BradPenney.io Network

This site is part of a family of progressive technical learning resources:

• Exploring Electronics — Electronics and physical computing from first principles
• Exploring Linux — Linux for developers and platform engineers
• Exploring Python — Python automation for platform engineers
• Exploring Computer Science — CS theory for working engineers

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