How to create and prepare design for CNC machines (laser cutter, milling machine, router, etc)

This is a quick write up about how to create and prepare designs for CNC machines (laser cutter, milling machine, etc).

The software tools used are SketchUp and Inkscape.


1. The use of Sketchup is not a must. However, if you have a 3D design and you want to produce it using materials cut with laser cutter / CNC milling machine, it would be easier to first do the 3D design in Sketchup, convert it to 2D, then export the 2D design in SVG format for further process in Inkscape.

2. There are at least 2 file formats supported by Inkscape that could be used by CNC machines. One is PDF (it could be imported and used by CorelDraw), the other is DXF. If you plan to use DXF format, be sure to install the latest Inkscape (v1.0) because the scaling of the objects saved in DXF format is incorrect (too small) in the previous versions. More about this could be found in the link below.

3. Some shops will ask you for design file in DWG format. You could either use PDF to DWG converter (not all of them are free and some of the converted results are not so good or have a watermark on them) or ask whether they could take file in DXF format instead.

Scaling issue saving DXF from Inkscape

The Sketchup Part

Step-1: Launch Sketchup. Before starting the design, be sure to set the Camera to "Standard Views - Top" and enable "Parallel Projection".

Step-2: Create the design.

Step-3: After the design is completed. Holding down the left mouse button then drag the mouse to select the design to be exported as SVG. Once done, click on the SVG plugin icon.

Step-4: Select the path and filename to which the SVG will be exported to at "Save SVG to the following file" then click the Save button to save it.

The Inkscape Part

Step-1: Double click on the saved .svg file to open it.

Below is a front panel design that I designed for one of my projects and I want to create 4 PCs using laser-cut acrylic.

Step-2: The size of the current template isn't enough to hold 4 PCs of the design. To change it, go to "File" -> "Document Properties..." to bring up the document properties window.

Step-3: The size of the template can be changed by changing the Width and the Height under the "Page" tag. Be sure to close the Document Properties window when done.

Step-4: Select the design to be duplicated then use copy and paste to make 3 additional copies.

Step-5: Select the 4 objects. Double click on stroke to bring up the Fill and Stroke window.

Step-6: Go to "Stroke style" then set the width to 0.1 px.

After hitting the Enter key, the lines become much narrower.

Saving the Inkscape design in PDF format

Step-1:  Select all the parts then go to "File" -> "Save As".

Step-2: Select "Portable Document Format (*.pdf)" then click on the "Save" button.

When prompted, use the below settings.

Step-3: Open the saved pdf file to check its content. If all is good, then the file is ready to be sent to the shop to be used by the CNC machines.

Saving the Inkscape design in DXF format

Step-1:  Select all the parts then go to "File" -> "Save As".

Step-2: Select "Desktop Cutting Plotter (AutoCAD DXF R14) (*.dxf)" then click on the "Save" button.

Use the setting below. Then click OK to proceed.

Verify the saved DXF file using AUTODESK VIEWER

1. Lunch the service at https://viewer.autodesk.com/designviews

2. Load the dxf format design file.

3. Check the dimension of the object using the Measure tool.

4. Click on Distance to measure the dimension of the object.

Note that if you use Inkscape version prior to V1.0, the dimension of the measured object will be around 3.5 times smaller.




PDF to DWG (DXF) using free open source Inkscape


Below are some of the results of PDF to DWG conversions.

PDF to AutoCAD -Free Online

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