Create a Fusion 360 Model from an Eagle BRD File

by | Sep 30, 2017 | Fusion 360, Robotics |

Whether you are working on a robotics project, a consumer product, an IoT device, or any other design involving printed circuit boards and hardware coming together in an assembly, it is highly useful to have a 3D CAD model of your PCB, along with the ECAD schematic and board files. This is especially the case for projects involving a PCB housed in a 3D printed or injection molded enclosure. Without a 3D model of your PCB it can be very difficult to evaluate the way the PCB will fit inside the enclosure. It can get very expensive and very time consuming to produce multiple prototypes just to work out things like mounting boss positions, spacing for electronic components, and cutouts for LEDs, buttons, or ports.

This tutorial will demonstrate how to build a 3D model in Autodesk Fusion 360 from a BRD file created with Autodesk Eagle.¬†If you don’t use these two software packages for your own design work, the general technique presented in this tutorial can be used in most other design software.

In this tutorial I will be working with the design files for an in-development IoT product, the Wello connected doorbell.

BRD example

This tutorial starts with a completed BRD file created in Autodesk Eagle.

3D model example

This tutorial demonstrates how to create an accurate 3D model of the PCB from the Eagle BRD file.

We don’t need, and in fact we really do not want, all of the Eagle BRD layers to be imported into Fusion 360. In general, we want to keep the visible layers to an absolute minimum because the more layers we import into Fusion 360, the more difficult the model will be to create. So, in Autodesk Eagle, click the Layer settings icon in the upper-left corner of the window. Then, click the Select None button to deselect all layers.

Hide all layers by clicking the Select None button.

With all the layers hidden, we can choose only the layers necessary to build the 3D model of the PCB. The exact layers you choose to select will depend somewhat on the design of your PCB, but in general you will want the board outline, and at least one layer that allows you to locate the components on the board. I typically use the Dimension, tPlace, and tStop layers.

Select the minimum layers required to locate components on the board.

If your design has a lot of through-hole components, you may also want to select the Pads layer.

With a skeleton crew of layers selected, we will export the BRD file in a format that can be imported into Fusion 360. Specifically, we will export the BRD as a DXF drawing. To do this, select File > Export > DXF.

Export the BRD as a DXF

In the dialog box that appears, choose a location to save the DXF file.

Now that we have a CAD drawing file of our Eagle BRD design, we can import that drawing into Fusion 360. Start a new document in Fusion 360, then, in the ribbon at the top of the screen, choose Insert > Insert DXF.

Import the DXF into Fusion 360

A dialog box will appear prompting you to select a plane onto which to import the drawing. I recommend choosing the plane with an orientation closest to the orientation that the PCB will mount into your enclosure. After you select a plane, navigate to the location where you saved the DXF from Eagle.

Choose a drawing to import.

Depending upon the complexity of your design, and the number of layers you selected in Eagle, it might take Fusion 360 a minute to import the drawing. Just be patient and eventually the DXF file will be imported into a sketch.

Import the DXF as a sketch in Fusion 360

At this point we have a nice (albeit somewhat messy) sketch of our BRD file in Fusioin 360 containing the board outline and features to locate all of the electronic components on the board. Now we can work from this sketch to create a 3D model of the board. The first thing to do is extrude the outline of the PCB to create a body that represents the actual PCB itself.

Now, we could simply select every single shape in the sketch at the same time and extrude all of it at once. However, with so many sketch features and probably a bunch of other lines, taking this approach is very annoying, quite slow, and prone to producing issues in the extruded body.

I find that a better approach is to create a new sketch on the same plane as the one onto which you imported the DXF and then trace the board outline. This way you end up with a clean sketch of the board outline. So, start by creating a new sketch from the navigation ribbon at the top of the screen.

Create a new sketch on the same plan as the imported DXF.

In your new sketch, simply trace over the outline of your PCB. If there are any holes in your PCB, like mounting holes or holes for PTH components, you can use circles to trace out these holes. Once you’ve traced around your board outline, you can extrude the shape to create a representation of your PCB. The distance you extrude the shape will depend upon the thickness of your manufactured PCB. For example, I use OSH Park to get all of my PCBs fabricated and they use a board thicknes of 1.6mm. Whatever thickness you are using, extrude the shape using a negative value of that thickness. This way, you will end up with a body in the shape of your PCB with the DXF sketch for locating components on top of the body.

Extrude PCB board outline (dimension layer).

When you are done, you will have a body the shape and thickness of your PCB, with a sketch on top for locating components in the next step.

The sketch on top of the body will allow you to locate the components on the board.

Now that you have a model of the PCB itself, it is time to add electronic components to the board. For almost all common components, and many less common components as well, and SMD packages, you can get 3D models from a couple sources. First, GrabCad is a site for sharing 3D models; GrabCad is actually integrated directly with Fusion 360 as a publication option under File > Share. I have yet to use any electronic component in any of my PCB designs that I have not been able to find on GrabCad. A second good resource is SnapEDA. I frequently use SnapEDA while designing in Eagle because it is a great site for getting Eagle footprints for all kinds of components. In addition to Eagle libraries, SnapEDA also offers 3D models of many components.

Once you obtain 3D models of all the components used in your PCB design, the components can be placed onto the board model just like any other component in a Fusion 360 assembly. The sketch created by the DXF you imported will show you the accurate position of each component.

Add components to the board.

Depending upon how many components your PCB contains, it can take some time to get all of the components placed. If you have any components arranged in a consistent pattern, for example groups of passive components like resistors and capacitors, you can make use of the patterning tools in Fusion 360 to speed up the process. By the time you are done, you will have an accurate 3D model of your PCB that can be used in the rest of your design work.