I use Blender to create my 3D designs. The designs are then 3D printed by Shapeways in various materials. I’ve done most of my models in sandstone and learnt how to get the prints to come out just the way I want using my own process.
Here is the process that I follow when making sandstone models:
- Design the model in Blender using the default scene unit settings (blender units). I consider each blender unit in the 3D space to represent 1cm in the final design.
- Consider the Shapeways design guidelines for sandstone. In particular, be aware of the minimum wall thickness and escape hole sizes.
- Use the ‘Blender Render’ for assigning material colors to your model.
- If your model will stand on a flat surface, you have to make sure you have a flat bottom or legs to make the model stand upright.
- Use the ‘Print3D’ addon toolbox to confirm that your model is good for printing. You can also use the free Netfabb Basic program to confirm that your 3D design is good.
- Save a copy of the model before making the final changes to make the model printable.
- If your model has a solid body, you need to hollow it out to save printing costs. I use the Blender solidify modifier to make the body solid with an internal wall and then use a boolean modifier to add an escape hole.
- Rotate the model 180 around the z axis so it is facing away from the front view (otherwise the Shapeways image renderer will show you the back of your model)
- Scale the model by a factor of 10 (this will make the model the right scale when imported to Shapeways in millimeters).
- Change the Blender scene units to metric.
- Use the Print3D toolbox option to export the model in the VRML2 format (this format will include the color data needed for printing full color sandstone). It will create a file with the “.wrl” extension.
- Upload the file to Shapeways using millimeter units.
- Shapeways will send you a confirmation email for the upload.
- Some time later your will get a confirmation email that the design has passed some initial tests to make sure your model complies with the printing requirements.
- Then you can place an order with a specific material.
- Another set of tests are done on the design just before printing and it can then still be rejected if it doesn’t comply with the design guidelines. You will get an email explaining why it was rejected.
- You will get another email containing the tracking number for the package delivery after the model is printed.
- In total you will wait about 2 weeks until you get your 3D model delivered.
Printing your model is really the only good way to make sure that your design is printable and that the final 3D object is a practical real-world design. I hope my process will help you to make it easier to get what you want.