If you’re like me, you’ve looked everywhere for a free CAD program to help aid your CNC projects. You’ve likely found Google Sketchup, but were unable to utilize it because there isn’t a way to export it’s models into a format useful for CNCing. Well stop your search now because I found a way to make the free version of Sketchup work and am now going to share it with you.
Even if you don’t know what a CNC is, this tutorial could still be useful to you, so don’t leave until you check it out.
Note: This trick only seems to work with 3D objects.
This tutorial will show you how to create DXF or STL files from Sketchup models. Well, actually you will learn how to turn Sketchup models into a variety of different file formats, but DXF and STL are generally the most useful to the CNCist. Once created, the these files can be loaded into MeshCam or CAMBAM Plus (or another similar program) and used to generate 3D G-code for your CNC.
The way this works is to first export a model built in Sketchup as a .kmz file. A .kmz file, normally used with Google earth, is really just a .dae file in disguise. By renaming the .kmz as a .zip extension and unpacking it, you will able to retrieve that .dae file and import it into Blender. From Blender, you can export a Sketchup model into just about any file format you could possibly want. (confused yet?)
Note: If you’re exporting to STL, you may want the How To Export STL Files From Google Sketchup tutorial first because it is quicker to export using the plug-in method described in it.
On to the Tutorial
The tutorial which will show you how to do this isn’t actually on my site. It’s on this guy’s here. (Don’t click the link quite yet) I suppose I could have simply redone the entire thing just to keep everything organized in one place, but that would be dishonest because it would be copying someone else’s work.
I do have a few things to say before I send you off to the above site. You see, that site assumes that you already have a couple things installed on your computer. It also assumes your computer is set up to show file extensions. I will tell you how to set these things up now.
Download and Install Blender
This first thing you need to do is download and install Blender. It can be found at www.blender.org. As you can see from the pictures in the gallery, it is one very capable program. What is also very cool about this program is that it is 100% free.
Download and Install Python
The next thing you need to do is download and install python (also free). You can find it at www.python.org. Python is a programming language, and you need to have it installed because Blender has to have access to its libraries for importing the .dae files.
Showing File Extensions
One final thing you need to do is set up Windows so that it will show file extensions. For example, you might have a picture named “mypic.jpeg”, but what Windows likes to do is cut off the .jpeg part so that it only shows up as “mypic”. You won’t be able to rename the .kmz file to a .zip file (or at least not as easily) until you turn this feature off.
You can find a tutorial for showing file extensions in Windows Vista here and another for Windows XP here. You could also google “how to show file extension in (your operating system here)” if you can’t access the above links for some reason.
Well that’s the end of my part of the tutorial. Follow the link here to continue on. Once you finish with that tutorial, you will have loaded a Sketchup model into Blender. From there, it is a simple matter of exporting it back out into whichever file format you need to create your G-code.
If your having trouble exporting your model, it is possible that the method for exporting at the How To Export STL Files From Google Sketchup tutorial might work instead. The method described on that page is also somewhat faster. Hopefully, one of the two, this one or that one, should work.