CAM Files Protocol

Computer Aided Manufacturing (CAM) files are toolpath files that enable a computer-controlled machine - such as a CNC Torch Table or a CNC Milling Machines - to produce parts automatically by using the CAM files as blueprints.

Examples of CAM files:

• DXF format for scale-model laser cutting - OSE Rapid Prototyping
• STL format for 3D printing - tubing for the Tractor Construction Set - scale models OSE Rapid Prototyping
• DXL format for cutting steel sheet via CNC Torch Table - the Brick Press CEB_Press_CAM_Files

Protocol

Special Note: The 'Sketchup SKP files to DXF or STL' plugin must first be installed locally. If you do not have the 'Export to DXF or STL' option under Tools, the plugin will need to be downloaded and installed. See below for installation instructions.

1. Open original file in SketchUp.
2. Ensure that all objects to be exported are aligned flat to the plane of the Z-axis. *Note: 3D objects aligned vertically will NOT be exported successfully.

It is possible to do this stage entirely in the original sketchup file. you can copy each piece and lay it out on the plane. because these are references to the original geometry, any changes to the model will be reflected in this layout. this layout can easily be exported again after changes are made to the model. make a separate component for the DXF export and paste in place all the components laid out. Be sure to delete any construction lines, radius cross hairs etc. It needs to be clean line work or the cnc cut may slice through undesirable places!

1. Select all objects that are needed for the CAM file. *Note: Ensure that all edges of desired objects are selected, faces are NOT exported during conversion, this is normal.
2. Go to File Menu and select command Tools > Export to DXF or STL.
3. Select "inches" in dialogue box drop down menu (selected by default), click OK.
4. In second dialogue box, entities to export, choose best option from drop down that matches needs of destination CAM software. *Note: The most often used type is 'polylines', and are typical for DXF files.
5. For STL export, select 'stl' from the second dialogue box (entities). The option is located at bottom of list in drop-down menu, below 'polylines'.
6. In the save dialogue, name the file (ensure file extension is correct), choose location, click OK. *Note: Ignore 'Save as type:' drop down menu.
7. Final dialogue box will report number of faces, lines, and objects converted. Click OK. *Note: Do not be alarmed by the 'objects ignored' count, the script must alter the objects' properties in order to convert the file.
8. Your CAM file is ready.
9. Documentation: Open CAM file in appropriate software, capture screen shots and embed images next to your CAM file on wiki.

Plugin Installation

1. Windows - Go to www.guitar-list.com/download-software/convert-sketchup-skp-files-dxf-or-stl in a web browser and download the appropriate version (skp_to_dxf.np for SketchUp 2014).
2. Navigate to your SketchUp Tools folder, for SketchUp 2014 in Microsoft Windows - C:/Program Files(x86)/SketchUp/SketchUp 2014/Tools
3. Linux - may have issues running Sketchup 2014 (2013 version worked) - now working on my Dell Inspiron - MJ
4. Copy the skp_to_dxf.np file into the Tools folder.
5. Restart SketchUp, installation is complete.

Other Resources

[some useful info on cutting tolerances, kerf etc to take into account when laying out CAM files]