Ugh! I’ve spent most of the evening battling myself and Google SketchUp! The two of us are formidable foes.

The challenge is this: Shapeways wants a super-clean mesh before they’ll attempt to print. That means normals all have to point the same way, and no hidden faces or lines.

Sadly, SketchUp likes nothing better than creating hidden faces and lines — it works best like this. When you see the slick demos online, rest assured that the resulting model is unprintable.

Doubly sadly, when I started the model, I was seduced by the powerful gestural language that the tool provides, and quickly did things like extruding rounded shapes for the window frames (who knows how they’ll resolve on the printer!), and sloping the window sill so the rain doesn’t run into the car.

So now, we need to make those two surfaces meet cleanly. Should be a simple matter of using the “Intersect” tool in SketchUp, right? Well no, because SketchUp doesn’t like working at the small scale I’m working in at all. I should have realized this was going to be a problem when SketchUp wouldn’t even let me create an arc .015″ in diameter, and I had to draw segments myself.

I probably wasted an hour trying to get it to fill in the odd shape at the foot of the window frames. Finally I gave up, and here is my solution: I drew a rectangle at the foot of the window frame, then bent the bottom of the frame so it fills the rectangle. Voila, the shape on the window sill is easy to fill because it’s all big squares, and the inside will have no hanging surfaces. I haven’t tried to upload yet, but I have high hopes that this will work for me.