@jim said:
The biggest limitation is that SketchUp does not have true arcs or circles. Everything is exported as line segments, and unless you used a lot of them, the segments could be visible on the finished part. Of course, this does depend on other factors such as the radius of the curve and precision of the machine. A small radius will probably not have visible segments, for example.
The shop is going to take the .dxf and generate gcode to run on the cutting machine. The gcode ironically does support true arcs, but again Sketchup exports only line segments so that is what the machine will cut. The more segments you model with, the smoother the finished part.
CNC machines and 3d printing have become affordable at a hobbyists budget. It's really too bad because Sketchup seems like a perfect fit otherwise, but this lack of curves makes it hard to recommend Sketchup for applications like cnc and 3d printing.
Wrong!
The plugin Phlatscript (sketchup to gcode) can transform the segments of an arc in instructions that specify a radius in the gcode.