New to CNC: Best way to generate the g-code for this sign

[drphil]

I have completed building my machine and have it working well, except for having a motor to become demagnitized. Waiting for replacement now. I have cut several demo projects without problem. I trying to cut the picture of the sign below. The blackouts are for privacy. I have drawn the image in Inkscape, so I have in in DXF and SVG formats. The pic is for ease of show here. I have tried various ways of encoding to G-code but have been unhappy with the results. The idea is to have all the white areas removed -.25" from the block faced leaving the black areas in standout. I have messed around with pycam, g-simple, lazycam and kcam. The best result was with image-to-gcode; however, with a 1/16" bit it took hours to complete and may have helped with the demagnetizing of my x-axis stepper. This is a large plaque about 15" x 15". I need some help and advice.

stumped.