Changing Material Colors for FDM 3D Printers | A Tip from a Tech

Stratasys FDM 3D Printers like the F900 and those in the F123 Series can print a variety of colors in ABS and ASA. Swapping between colors of the same material is a fairly simple process since the printer doesn’t require a tip change or recalibration – just unload the old material and reload the new one.

However, depending on what color is being swapped out, it may be necessary to perform an extra purge from the tip in order to fully flush out the old material. This step is especially critical when changing out a dark color (e.g. black or blue) to a lighter color such as ivory. Keep reading for more tips and tricks for color changing on FDM 3D Printers.

Changing color mid-print

Stratasys FDM 3D printers allow users to pause a print mid-build in order to change materials. The printer will do this automatically if it runs out of materials, but you can also program a layer pause in programs like GrabCAD Print. By doing this you can change the color of the layers from that point on, provided you continue using the same type of material. Here’s an example using a Stratasys Fortus 250 3D Printer.

First, open your part in GrabCAD Print and check that all of the typical print settings are adjusted. 

In this example, my goal was to have the base layers print black and the raised parts to print in white. 

Once all of your print details are finalized select “show slice preview” located in the upper right. 

For the purpose of inserting a pause, I find it easier to view it in the single-layer range.

This option will show only the currently selected layer, which you can adjust using the sliding bar on the left or the input box on the right.

At this point, I’ll look for the layer that is the very top of the base of the part, right before the raised details show themselves, then move up to the next layer, which will display only said details.

This is the layer I want to add the Z pause in because the printer will stop printing bringing before starting this layer. In my example, I’ll put the Z Pause on layer 23. 

Once layer 22 is complete, the print will pause, (since we have a GrabCAD Print Server setup, GrabCAD Print Mobile will alert me)  and I can then switch materials. 

At this point, I can now unload the model material and replace it with white. Considering the number of necessary layers still, I’m not concerned if my first layer of white isn’t perfect, so I didn’t bother to initiate additional purges beyond the purge that occurs once a new spool of material is loaded. 

Lastly, we can hit “resume” and the F250 picked right back up where it left off eventually yielding a finished product.

I hope you found this tip helpful, for more 3D printing tips and tricks.

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About the Author

Travis Testerman is a 3D Printing Field Technician based out of Fisher Unitech Headquarters in Pleasant Ridge, Michigan. Travis is a certified expert for the maintenance and operations of Stratasys 3D printers. As a field technician, Travis meets with customers daily and is adept at identifying 3D printing challenges and educating his customers about best practices for use and maintenance.