Quartz: Rhino Python Script.py

# Modified from : https://github.com/timcastelijn/gcode-generator
feedrate= 85   # Carriage Speed | Increment by +- 5 
curve_tolerance=0.008
curve_angle_tolerance=5
z_offset = 0
material_mult = 0.01  # Extrusion Speed: A-Axis | Increments of +- 0.001
extruder_axis = 0   # Rotation A-Axis

import rhinoscriptsyntax as rs
import math

pt_prev = [0,0,0]
path = rs.GetObjects("Select Curves/polylines/arcs/circles", rs.filter.curve, True, True)
filename = rs.SaveFileName ("Save", "Toolpath Files (*.nc)|*.nc||", "/users/timcastelijn/documents")

file = open(filename, 'w')

# write header
file.write("G21\n") # Measurement units to mm
file.write("G90\n") # absolute positioning

for curve in path:

    # fast move to path start
    pt = rs.CurveStartPoint(curve)
    file.write("G00 X%0.4f"%pt.X+" Y%0.4f"%pt.Y+" F%0.4f"%feedrate+"\n")

    # detect type of curve for different G-codes
    if (rs.IsPolyline(curve)) or rs.IsLine(curve):

        points = rs.CurvePoints(curve)
        for pt in points:
            dist = rs.Distance(pt_prev,pt)
#            file.write("dist%0.4f "%dist+"\n")
            pt_prev[0] = pt.X
            pt_prev[1] = pt.Y
            pt_prev[2] = pt.Z
            
            extruder_axis += dist*material_mult
            file.write("G1 X%0.4f"%pt.X+" Y%0.4f"%pt.Y+" Z%0.4f"%(pt.Z+z_offset)+" A%0.4f"%(extruder_axis)+"\n")
    
    elif rs.IsArc(curve):
        normal = rs.CurveTangent(curve, 0)
        
        # get curvepoints
        startpt     = rs.CurveStartPoint(curve)
        endpt       = rs.CurveEndPoint(curve)
        midpt       = rs.ArcCenterPoint(curve)
        
        # calc G2/G3 parameters
        x   = endpt.X
        y   = endpt.Y
        i   = -startpt.X + midpt.X
        j   = -startpt.Y + midpt.Y
        
        # make a distinction between positive and negative direction
        if ((normal[1] > 0) and (startpt.X > midpt.X)) or ((normal[1] < 0) and (startpt.X < midpt.X) or (normal[1]==0 and (normal[0]==1 or normal[0] ==-1) and startpt.X == midpt.X)):
#                file.write(";positive ARC ccw \n")
            file.write("G3 X%0.4f"%x+" Y%0.4f"%y+" I%0.4f"%i+" J%0.4f"%j +"\n")
        else:
#                file.write(";negative ARC cw \n")
            file.write("G2 X%0.4f"%x+" Y%0.4f"%y+" I%0.4f"%i+" J%0.4f"%j +"\n")

    else:
        print "curve detected, subdiv needed"
        
        polyLine    = rs.ConvertCurveToPolyline(curve, curve_angle_tolerance, curve_tolerance)
        points      = rs.CurvePoints(polyLine)

        # insert division points as line
        for pt in points:
            file.write("G01 X%0.4f"%pt.X+" Y%0.4f"%pt.Y+" Z%0.4f"%(pt.Z+z_offset)+"\n")
            pt_prev[0] = pt.X
            pt_prev[1] = pt.Y
            pt_prev[2] = pt.Z
            dist = rs.Distance(pt_prev,pt)
            file.write("dist "%dist+"\n")
        # remove objects after use
        rs.DeleteObjects(polyLine)
file.close()