Full Color Polyjet Printing: Fusion 360 Tutorial

3/28/2024

We are often asked how to design files for our full color 3D printer, the J750. The process depends entirely on what the goal of the project is, and in which CAD environment the part is being created. For gradients and intricate color patterns, for example, it can be necessary to use an animation-friendly software like Blender. But for typical engineering applications, Fusion 360 (or other CAD programs) is all you need. Here's a quick tutorial to show you how!

This assumes you’re familiar with Fusion 360 and GrabCAD Print, and focuses on a couple tricky aspects of the process specific to those programs, but the general idea should be applicable to almost any software you might want to use to do this.

1: Model all Bodies Separately

Each differently colored area in the print will need to be a separate body. This is easier to do if you’re modeling from scratch and planning for this, but the “Split Body” command in Fusion 360 can be helpful, or going back in your timeline to set your various operations to “New Body” instead of “Join”

For this project, we’re making a USB key with the POP logo. I’ll start by modeling the USB key circuit board itself. Not going for ultimate accuracy here, just getting the basic shape down to ensure the case I make fits well:

Next I build the case up around it. I’ve set the material to clear to give an idea of what the final product will look like:

Then I add in the POP logo .svg file and use the Emboss command to raise the letters:

The “Emboss” command in Fusion doesn’t let you create a new body, unfortunately, so before I used it, I used the “Surface Offset” command to create a surface body on the outside of the case, to use as a tool for the “Split Body” command:

Finally I do the split and change the colors of the letters. These are just the standard Fusion “Paint” appearances, our colors are slightly different, but it gives the idea for now. I also added some internal fillets to the case to make the USB PCB slide in easily.

It’s looking great! Now I just add the QR code and some text to the back, using another .svg file. This text is a little small for an emboss, so I’m just going to extrude them into the case a bit, so they’ll end up flush with the surface. This makes it easy to make them a separate body, I just choose “New Body” in the extrude command:

Modeling the cap is a similar process, it also has separate bodies for co-molded rubber-like material for grip and to protect the contacts of the USB connector:

2. Use the “Export” Command

Now we’ll print the case on the J750 in color. The first step is to export some .stl files for GrabCAD Print to work with. Normally we’d just hit File - 3D Print in Fusion and select the body we want, but in this case we have a bunch of bodies that all need to be the same color, and a few others that want different colors. I’ll hide everything except the parts that get printed black, and do File - Export:

This will allow me to create ONE .stl file for all the black pieces, instead of each little segment of the QR code, each letter, number, dash, and dot being a separate .stl that we have to set up in GrabCAD. I make .stl files for the other parts using the File - 3D Print workflow (export takes longer because it requires “cloud translation” in Fusion). I like to put the hex color code for each part in the filename so it’s handy when I’m setting up the parts in GrabCAD. As a printing service, we would handle things from here (but will show you the process below in case you're curious!)

3. Add as Assembly to GrabCAD

Step 1 in GrabCAD is to ignore the big blue “Add models” button, even though that’s what we’re going to do, and go to File - Add as Assembly:

If we add the .stls separately using the “Add models” command, they’ll get spread out all over the tray, instead of printing as one part. Now we just have to set the colors:

The black and clear just come from the “Tray materials” and will be pure VeroBlack and VeroClear, while the red and blue are easy to set using the color picker since we put the hex code in the filename: