Prepping for 3D Printing – Part II

In order to get all of the ‘kinks’ out of your design you will probably find the following software useful. (Note: This is the way that *I* do it. If you ask a dozen people you will probably get a dozen different ways. Like anything else .. whatever works .. works)

  • MeshLab – [free] an open source for the processing and editing of unstructured 3D triangular meshes, providing a set of tools for editing, cleaning, healing, inspecting, rendering and converting meshes.
  • netfabb Studio Basic – [free] this program provides mesh edit, repair and analysis capabilities.

In the next part I will talk about how we can use these programs to get our file ready to upload. Beyond that .. they have mind-boggling capabilities that I haven’t even began to explore.

Create the STL file
First off – with a model that you are happy with you have to export from Google Sketchup.

File >> Export >> 3D Model

The default Export type should be a COLLADA file (*.dae). You can use the default File name which will be the name of your Sketchup file with a .dae extension or put in something that makes you happy.

Suggestion. The VERY first thing you should do before you go any further is set up a file system. Here’s an example: Suppose you create a 6-in Gate Valve. You might set up your files something like ..

My 3d Files –
— A fire plug
— A Gooseneck Lamp
— A Gate Valve
— — 12-in
— — 6-in
— — — Full scale
— — — 1-48 scale
— — — 1-87 scale

The point is .. if you don’t set up a ‘system’ you will find yourself searching for that file you just KNOW is there .. somewhere.

Now. Open MeshLab and ..

File >> Import Mesh >> .. and browse to where you saved your .dae file you just exported from Sketchup. Leave the “Pre-Open Options” to Full Scene and click “OK”. The file will load (the larger it is the longer it takes – duh). Note. After the object loads to the screen you can move it around using the mouse. Middle mouse button lets you move up/down and left/right while the Left mouse button lets you rotate the object.

MeshLab allows you to do just about anything you can think of with a 3D mesh. It was designed by geek for geeks so can be pretty intense! For now you can ignore all the ‘cool stuff’ since we are only using the program to create a STL at this time .. except .. there are two things I always do with a mesh in MeshLab.

Let’s clean up that mesh a bit. First we want to bring up layers screen. Look at the row of icnons along the top of the screen. The seventh icon from the left looks like a stack of paper. That is the “Show Layers Dialog” button. Press it and the Layers screen opens up on the right. Here, you can do all sorts of mad things .. adding meshes to separate layers, mergeing, duplicating and so on. Just for now, we are going to clean up our single mesh.

Filters >> Cleaning and Repairing >> Remove Duplicate Faces – this normally does nothing since if you are working in Sketchup correctly you have already done this .. but still doesn’t hurt and will catch duped faces.

Filters >> Cleaning and Repairing >> Remove Duplicate Vertex – This is much the same but will remove literally THOUSANDS of duplicate vertexes in a complicated mesh.

With this done make sure that the changes have been applied. In the Layers Dialog box right click your mesh. From the context menu select Freeze Current Matrix.

Now we can export the mesh as a STL

File >> Export Mesh As >> .. From the drop-down on the bottom select ‘STL File Format (*.stl) .. enter a File name or leave as is .. browse to where you want to put it and click ‘Save’.

Follow the Rules
There are several important things that need to be taken care of before you can upload the file. Shapeways has a tutorials on doing this including checking for Watertightness and Manifoldness – Things to keep in mind when designing for 3D printing

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