Welcome back to the Fusion Mastery series! In the previous installment, we dove into the world of Fusion Team, where we learned how to collaborate with anyone, on any device. While Fusion Team is perfect for collaborating on Fusion 360 designs, what happens if you need to work on a design from another CAD tool? That’s where the age-old practice of importing and exporting comes into play. In this article we’ll be covering how to import and export any CAD file in Fusion 360, and also review the variety of CAD files you’ll see out in the wild.

Native vs. Neutral File Formats

If you’ve ever opened a generic CAD file in Fusion 360, chances are the results have been inconsistent. One might be comprised of hundreds of surface bodies, while another might not show up at all. And what happened to some of the minute detail from the original model? Importing and exporting any kind of CAD file can introduce translation issues.

The freedom of design files jumping from tool to tool, increases a potential for a sacrifice in quality. Knowing this, it’s important to choose the right file type to maximize the quality of your design as it gets sent from one engineer to another.

CAD file formats can be categorized into one of two buckets – native and neutral. Native file formats are native to the tool they originated from. This means the maker of the software owns the file format technology and can make changes to it as they please.

Neutral file formats originate from some kind of standards-making organization. This group considers not just one tool, but how their file format will be used across the entire spectrum of CAD software. The goal is to make these file formats easily exchangeable between any CAD tool.

With all that in mind, let’s talk about some of the most popular neutral file formats you’ll want to consider when exporting your next design:

STEP

The Standard for Exchange of Product Data (STEP) is one of the most popular neutral file types and is governed by ISO standards. If you’ve worked with just about any 3d CAD too, you’ve likely already handled a STEP file. This format has a number of advantages over other neutral formats, including:

• More data. STEP files include tolerance information, which provides useful data for precise machining applications.
• More versatility. The STEP format is governed by ISO standards and has been adapted to support many specialized engineering disciplines over the years.
• More intelligence. STEP files reference each individual part within a design instead of replicating the same part X amount of times, this makes it perfect for assemblies.

IGES

The Initial Graphics Exchange Specification (IGES) used to be the reigning champion of CAD file formats until STEP came along. This file format includes geometric data for a model, but doesn’t contain any information about the relationship parts have within an assembly. It also doesn’t support solid modeling out of the box.

You might still find IGES files floating around, but we wouldn’t recommend using them for translating your modern CAD designs. As of this writing, the IGES standard will not be seeing any future updates.

Parasolid

The Parasolid file format is owned by Siemens and can be licensed by any company that wants to hand over the dough. This format includes a CAD kernel that ensures its compatibility across a variety of tools. Parasolid supports a variety of modeling techniques, including:

• Solid modeling
• Freeform surface/sheet modeling
• Graphic rendering support including tessellation

DXF

The Drawing Exchange Format (DXF) is the native 2D file format for AutoCAD. We’re including it here because AutoCAD is so widely used, and nearly every CAD software supports DXF. This format is great for bridging the gap between old and new software, but it doesn’t support the latest technologies like solid modeling.

STL

The Standard Tessellation Language (STL) file format is widely used in 3D printing, scanning, and some CAM applications. This file format represents a model in a pure triangular mesh, but doesn’t include any of the object’s rich parametric data. These limitations make STL fine for 3D printing, but not preferred for 3D CAD tools.

Native vs. Neutral

We won’t be covering the specifics of native file formats since they are reserved for their particular CAD tool. However, it’s important to talk about the distinction between native and neutral in your everyday design workflow. Your CAD tool will obviously work best in its own native file format without any loss of data or quality.

When you start translating CAD data from native formats to neutral, it’s normal to see a certain loss in features and quality. For example, if you export a design as a STEP or IGES file, you lose all parametric data. This basically turns your design into an empty model that you would have to add intelligence back into in another CAD tool.

Point being, when working with neutral file formats be prepared to spend some time “massaging” an imported file back its original glory. If you want to skip all of this busywork, then consider getting your fellow designers a free trial of Fusion 360, no file imports/exports required!

When working with native file types in Fusion 360, be on the lookout for two types:

• F3D. This is the default file type for a single design, which can include single/multiple components.
• F3Z. This packaged file is used for distributed designs, that contain externally referenced F3D files.

That covers the basics of CAD file types, let’s learn how to import and export in Fusion 360 now!

Importing a CAD File in Fusion 360

First off, you’ll need a CAD file to practice your importing skills with. Here’s a sample IGES file to download.

Importing generic CAD files works just the same as uploading a Fusion 360 design. You’ll first swing open the Data panel, navigate to a project, and select the Upload button.

From here you can select the IGES file you just downloaded and press the Upload button. Once the upload process completes go ahead and close the Job Status window.

Open the sample IGES file in your canvas and you should see a fancy looking model like the one below:

There are a few things to make note of about importing generic CAD files like this one. First, after importing your file it’s going to default to the Sculpt workspace. This can be changed in the Fusion 360 preference as shown below:

Second, you’ll also notice that this file does not include a design timeline at the bottom of the canvas. To turn this on, right-click the file name in your Browser and select Capture Design History.

Select the + icon on your newly added timeline and you’ll see two entries, one for the initial import and another for something called Base Feature 1. This is just a generic name that a solid or surface body is given when imported.

Lastly, some imported objects come into Fusion as a collection of individual bodies instead of one solid body. In your browser, expand the Import:1 folder, then expand Bodies. You’ll see an Unstitched folder with 6 individual bodies inside.

How did this happen? When you save an IGES file there are usually options to save it as a surface or a collection of surface bodies. We can quickly stitch these bodies together by first switching to the Patch workspace.

Within the Patch workspace, select all of the bodies listed in the Unstitched folder by shift + left-clicking. Once they’re all selected, expand the Modify options in the Patch workspace toolbar and choose Stitch. We’ll keep all of the options in the Stitch dialog at default and select OK.

Once the stitch is complete, take a look at your browser. Those 6 unstitched bodies should now be one Body 7.

At this point our IGS model has been successfully imported and stitched together in Fusion 360. Save the file, give it a change description, and you’re now working on V2!

Exporting a CAD File in Fusion 360

Now that we’ve seen how to import a generic CAD file, how can you export this same file to another CAD user? There are two options to explore:

Exporting From Fusion 360

With your IGES file still open, select File > Export. The Export dialog will open, giving you a few file type options, along with the ability to save the file to Fusion cloud or your computer.

You might notice that the dropdown of supported file types is a little light. If you don’t see your format in the list then it’s time to head into Fusion Team.

Exporting From Fusion Team

Fusion Team isn’t just a great place to review designs, it’s also where you’ll find a ton of file format options. To get to Fusion Team from Fusion 360, select the Open Details on Web link for your imported design in the data panel.

Once your design is open in Fusion Team, select the Export icon in the top right to get a lengthy list of export options.

Select one of the available file types and then select OK on the export dialog. Your exported file will be emailed to you soon!

This workflow works great if you know what type of file your fellow CADster needs, but what if you don’t know? In this situation you can share a link to your design in Fusion Team and let them decide.

To do this, select the Share icon in the top right corner of Fusion Team. In the Share dialog, copy the link that’s provided and send it to your fellow CAD user.

After opening the share link in a browser, they’ll see your design and a handy Download button in the top right corner. Selecting this will give them all the export options you already saw.

All they need to do now is choose one of the file formats and enter their email to have the file sent their way. Done and done.

You’re Now a Certified File Juggling Pro

Importing and exporting CAD files has never been ideal, but it’s an important part of an engineering workflow in today’s world of distributed teams. Until that magical day arrives when there’s one CAD tool to rule them all, get used to working on projects where different files from a variety of tools are being tossed back and forth. Just remember, translating a design from native to neutral is going to require some post-import love. You might need to spend some time stitching surface bodies together or adding parametric data back in. That’s just a part of the flow.

Already tired of the back-and-forth of import/export just reading this blog? Fusion 360 makes it easy to collaborate and share designs with everyone on your team without ever tossing files around. Try Fusion 360 for free today!