This is Going to be Reviting!

By Timothy Shotts

This is going to be a two-part tutorial to create STL (stereo lithography) files for the CNC and 3D printers.  I primarily use Rhino, Sketchup, and Revit for modeling so that’s what I’ll go over here.  I’ve broken it down into two sections – Sketchup to STL, and Revit to STL.  For reference, I will be using Rhino5, Sketchup Pro 2013, and Revit 2013, so YMMV.

Part 1:  Sketchup to .STL

Rhino5 will not open a Sketchup file more recent than V8, so down-save a copy of your model.

1.  Open your Sketchup V8 file in Rhino

Accept the default SKP Import Options

2.  When I import files into Rhino, they come in as millimeters, so I’m going to change the units to inches for the CNC.

In Rhino’s Command line, type “units”

Now my site model is 11,520” x 11,520”.  Great!  Almost done.

3.  Scale to the correct size.

I want my model’s scale to be at 1”=64’, so in Rhino’s command line I’ll type in “Scale”, select all my geometry, set the origin to (0,0,0), and the scale factor will be 1/768  1/768

Now my site model is 15” x 15”, a very manageable size.

4.  Export model as a STL file.

Select all your geometry to export, and type “export” into the command line.

Make sure your Export Options window looks like this.

CONGRATULATIONS! You are now ready to CNC your Sketchup model.

Part 2:  Revit to .STL

1.  Go to the Default 3D View

2.  Export a DXF file

DXF Export window will open and click Next…

Make certain that the file type is a 2010 DXF.  Rhino5 will not open a 2013 file.

3:  Open file in Rhino5

Since my Revit model was in feet and inches, I am going to import my file into Revit using inch units.

Double-check that your model is at the correct scale.

4.  Scale your model for fabrication.

I’m going to 3D print this model at 1:100 scale, or 1/1200

Great!  Now I have a 3D model that is about 4” x 5” and will fit on the Replicator’s platform.

5.  Change units.

The Replicator needs the units to be in millimeters.  You can do this in the Makerbot software, but I prefer to do it beforehand.

In Rhino, type “Units” into the command line, change the Model Units to Millimeters, and choose “Yes” to scale the model.

6.  Export model as a STL file.

Select all your geometry to export, and type “export” into the command line.

Make sure your Export Options window looks like this.

CONGRATULATIONS! You are now ready to 3D print your Revit model.