Basic workflow for 3D design in Sketchup and 3D printing @ home:
1. Pull your free copy of Sketchup down at: http://sketchup.google.com/
2. Install Sketchup
3. Download additional ruby scripts that will help you develop solid objects in Sketchup:
a. Allows you to export .stl files directly from Sketchup - http://guitar-list.com/download-software/convert-sketchup-skp-files-dxf-or-stl
b. Solid Inspector helps you track and deal with any lines/surfaces that otherwise invalidate your object being “manifold” which means you have reversed faces or cavity openings in your structure http://forums.sketchucation.com/viewtopic.php?f=323&t=30504
4. Drop the above downloaded ruby scripts into your Sketchup installation directory under the “Plugins” folder: Windows – (P:\Program Files (x86)\Google\Google SketchUp 8\Plugins), Mac – (HD/Library/Application Support/Google Sketchup 8/Plugins)
5. Startup Sketchup and chose the “Product Design and Woodworking” template that is in millimeters; get creative (about as far as I can go in this write up, good thing Sketchup is very intuitive, start here for help designing: http://sketchup.google.com/intl/en/training/videos/new_to_gsu.html )
6. Once you think you have something ready for export, make sure you have exploded any groups and run the Solid Inspector from the “Tools” menu. Look for red circles and evaluate what you need to change/delete in order to acquire an air tight manifold structure.
7. Now that your “solid” you can export the selected object/group in Sketchup using the “Export to DXF or STL” tool from your “Tools” menu bar. When prompted chose Millimeters for your export unit and “stl” for your “Export to DXF options” then save to disk.
8. I take that .stl file and open it in ReplicatorG (free): http://replicat.org which is a nice suite that allows you to interface with your printer and generate the code needed for digestion by your printer.
9. I position the object on the virtual build platform in ReplicatorG and rotate/scale if necessary
10. I then generate or “slice” my Gcode from my specified Skeinforge settings: http://fabmetheus.crsndoo.com/wiki/index.php/Skeinforge (don't let this scare you too much, most 3D printers have templates to utilize and Skeinforge is actually packaged with the ReplicatorG from above)
11. **Notice that everything above this point can be done without an actual 3D printer! You could stop here and simply upload your .stl file from step 7 to: http://www.shapeways.com/ and have your object mailed to you (for a fee of course)**
12. Once I have my Gcode processed I visually review the textual Gcode and then click "build". The instructions are sent via USB to my 3D printer and it begins its extrusion process usually set at 30mm/second
13. At this point your done, sit back and watch your bot go! It is very, very rewarding watching your digital design develop right before your eyes. Be sure to share your designs with others as this community is very open and has tons of shared assets out there for you to utilize! Here is a video from my 1st run on my bot; it was like 2:AM and I was running completely on Mountain Dew and just had to film my 1st calibration cube print because I was so stoked that I got it all assembled in a day’s time and it didn’t explode in my face! http://www.youtube.com/watch?v=Y8kbnj0_Spk