Building a Mac OS X version of Candle GRBL controller application with G-Code visualizer written in Qt

As a new owner of a 3018 Pro Milling machine using a GRBL 1.1 controller I needed a program to download G-Code to the CNC Mill.

Windows / Linux users have a few choices including:

While UGS (Universal GCode Platform) does run on Macs, it is Java based and feels a bit resource intensive. So I tried building Candle and it is a fairly easy compile as the developer has done most of the work.



  • Install brew from
  • Install the Qt5 dependency:
    • brew install qt5
  • Determine which version and directory the dependency is located in:
    • ls /usr/local/Cellar/qt@5
  • Download the current version of Candle from
  • Change to the src directory
  • Make the Makefiles with CMake:
    • env Qt5_DIR=/usr/local/Cellar/qt@5/5.15.2 cmake CMakeLists.txt
  • Make with make:
    • make

Why no brew formula?

While I would have liked to write a brew formula to make it easy for others to install Candle, the project fails to meet a number of criteria required. In particular, the version that builds is not a stable released version.


While not included in Brew it still is an easy build and looks like it might be the winning application for running the mill