If you have a bed size other than 200×300 you can change the config on the MicroSD card supplied with the c3d.
1. Access the micro SD card directly from your computer (not from mass storage)
2. Open the config.txt file
3. Find the ## endstops section
4. Find beta_max and change that value to match your bed’s Y dimension
5. Save to micro SD
7. make bed size match in lighburn with origin set to bottom left.