FAQ and Troubleshooting

bCNC is not starting

Do you have latest git master or latest stable version? Do you have all dependencies installed? Do you use right python version (2.7 vs 3)?

My machine sometimes suddenly stops in mysterious ways

Do you have unshielded cables too close to each other? Too long USB cable? Does this happen with other g-code senders?

bCNC shows error:X

Click on it to get details or read latest GRBL error code table: https://github.com/gnea/grbl/wiki/Grbl-v1.1-Interface#grbl-response-messages

bCNC refuses to run my perfectly good g-code

Try different g-code sender and let us know if it fails only in bCNC

Connect to motion controller using plain old terminal emulator, eg. Putty on windows, or screen for Linux users: screen /dev/ttyUSB3 115200 (to exit: ctrl+a k y) Paste the commands directly to this window

I think that bCNC sends bullcrap to my motion controller

You can use following command to connect to debug serial traffic. ttyUSB0 is real HW, ttyUSB23 is gonna be new fake device to which you'll connect the bCNC in order to intercept trafic:

interceptty -l /dev/ttyUSB0 /dev/ttyUSB23 | interceptty-nicedump

Rendering is slow and some lines are missing. Rendering burned my house down, ate my wife and druged my dog.

We know. Increase timeout in top right corner and wait.

In machines with High DPI (i.e. 4K and higher monitors) the interface font is extremely small

If you are using Windows 10, you can customize how each application behaves in regard to the HiDPI settings for windows. Just right click on the shortcut for bCNC, click on Properties, Compatibility, Change High DPI settings, and you can try some of the settings there.

Windows 10 HiDPI settings