CNC Surfacing / Thicknessing G-code Generator

Assumes XY zero = front-left of the workpiece and Z0 = spoilboard/bed. Toolpath overlaps edges by the margin you set.

Stock dimensions
Overcuts past the stock boundary on all sides.
If your Z0 is the bed/spoilboard, this is stock top height.
The program faces down to this height above the bed.
Tooling
Typical surfacing: 50–70%.
Machine + feeds
Retract height for rapid XY moves (clamp clearance).
GRBL may ignore RPM control depending on your setup.
Output 

      
    


    
    

      Top-down preview
      

        
        

          Stock outline
          Cut coverage (tool edge)