Opti-Mill is a free, open-source CNC milling companion tool that makes it easy to create G-Code for simple shapes without needing a complex 3D CAD or CAM package. It’s designed for machinists and hobbyists who want to go from concept sketch to machined part — without the software bloat.
Unlike traditional CAD/CAM software that can be overkill for simple jobs, Opti-Mill focuses on quick, straightforward part creation paired with smart machining calculators. This makes it perfect for learning CNC basics, prototyping, or making one-off parts — all while keeping control of your cutting parameters.
Opti-Mill Features:
Generate G-Code for Simple Parts – Create toolpaths for basic milling operations quickly and easily.
Calculate Speeds & Feeds – Determine optimal spindle RPM and feed rates for different materials, tools, and drill sizes. Expandable using JSON file.
Tap Drill Lookup – Built in tap drill size, and clearance drill chart for common thread pitches. Expandable using JSON file.
Material & Tool Database – Access preloaded cutting data or customize it for your machine and tooling.
Interpolation Support – Get accurate data even for in-between drill sizes.
User-Friendly Interface – A clean, organized layout makes it approachable for beginners while still useful for experienced machinists.
Open Source:
Download the application from Github for free under the GNU 3.0 license.
Customize the open source Python and JSON code to meet your needs.
Build together by contributing improvements to the Open Source community.
Please remember this is a project that may or may not continue to grow. I’m just sharing a tool I’ve wanted as a hobby machinist.