Sketchup 3D printable objects tutorial

Draft

Introduction

Google sketchup is currently probably the easiest 3D modeling program. It can be used to create simple 3D models for printing with a 3D printer like the RapMan

Prerequisites: Know how to print with a RapMan (or similar)

Tools needed

(1) Download Google SketchUp. We will work with the free version. The professional version not only has more features, but also could export directly to .OBJ which then can be imported to skeinforge.

(2) Download MeshLab. We will need this to convert SketchUP output to the .STL format.

(3) Download netfabb (free Studio version). This is needed to fix the STL file.

(4) Download Skeinforge. This can import STL and generate the g-code. Note: A next version of netfabb can do this too.

Sketchup basics

Settings and concepts

Startup

Select the template: Product and Woodworking

Configure the Interface

The interface can be configured:

• Select Menu: View->Toolbars->Large Tool Set

The Axis

The push/pull tool with an example

The Push/Pull Tool allows to push and pull faces to add volume to or subtract volume from models.

To create a small solid cuboid (3D rectangle):

• Zoom in a lot (mouse wheel) and make sure that you can see the origin (use the hand tool to drag)
• Select the rectangle tool: Draw a rectangle by clicking to a first point, dragging and then ckick/releasing the mouse. Make it about 60mm
• Select the Push/pull Tool: Click on the rectangle and move up (about 5mm)

To create a a void (empty) space:

• Principle: Draw a 2D shape on a 3D geometry (e.g. the cuboid above) and then push until it is "on face", i.e. exactly meets the back end.
• Now make a hole with the circle tool.
• Select the Push/pull tool, move over it the circle (it should high-light with blue dots). Now push it down (slowly!) until the tool says "on face". Release the mouse and you will see a hole.

Now let's make holes with letters as shown in Gift Tags by Roboteernat.

Select the 3D tool

• Set height to 100mm
• Untick extruded (letters must remain 2D)
• Set form filled
• Click "Place" and place it on the rectangle (make sure it's "on face")
• Right-click (object must be selected) and explode
• Push each letter down as explained above. This is a bit tricky, tilt the object (e.g. to a 60 degree angle) and zoom in (else you can't select the letters). Make sure to push util the tools says "on face" !

Export as Collada

• File->Export->3D Model; Select Collada

Sketchup to STL

Since the free version of sketchup doesn't allow you to export directly to .STL, there are two options:

1. Export to Collada .dae (a known 3D file format for exchange) and then import to a tool that can translate .dae to .stl
2. Install a plugin, e.g. Convert Sketchup SKP files to DXF or STL

We will use option 1, i.e. use Meshlab to translate Collada to .STL. Since the Collada export is not necessarily great, importing the result to a tool doesn't mean that export to STL wil be correct.

• Open MeshLab and import the Collada .DAE file
• You should see the object from the top (z axis is forward/backward)
• Export to .STL

STL to g-code

Size may be wrong, e.g. when we imported the object we made above to NetLab, the object was ok, i.e. not fixing was needed, but it shrunk to very small. ...

• Rezize and fix the object with Netfabb
• Import to Skeinforge and generate the gcode

Links

• Google Sketchup
  • Help/Manual
  • tutorials with models