Taking on new kinds of 3D printing projects always leads us to explore new skills and techniques. In this series of posts, we’ll share what we learned about some cool post-processing methods as we made 3D-printed trophies for the first time.
Early this year, Cisco asked us to create a 3D-printed trophy for CyberPatriot IX, a nationwide computer network security skills competition for high school and middle school students created by the Air Force Association. Cisco is one of the sponsors and it hosts the Cisco Networking Challenge during the CyberPatriot National Finals.
“We like to encourage our 3D ThinkLink students to find useful things they can do with a 3D printer and this trophy sounded like a great useful thing to do,” said Tom Meeks, our Director of Instruction.
We experimented with designs for the trophy and settled on one modeled after a Cisco router. After making prototypes with our Z450 powder bed printer, the next challenge was to give it a shiny, metallic finish so it would look like a trophy instead of a piece of electronic equipment.
|Cisco router used as model for trophy design|
The Z450 creates 3D objects by spreading layer after layer of starch-based liquid binder on a bed of gypsum powder. After drying, the parts are coated with a super-glue-like infiltrant or thin liquid epoxy. This strengthens the piece, but the surface still feels rough, like unpolished stone instead of smooth metal.
|Trophy prototype before and after basecoat application|
Working with Bill Leckliter at Chrome Finishes, Inc. in Frederick, Maryland, we learned now to transform our powder-and-glue box into a trophy that appears to be chrome plated using the Cosmichrome process. First, Bill sprayed it with glossy basecoat primer to make the surface smoother. Then he sprayed on the Cosmichrome plating chemicals, which react with the basecoat to produce a metal reflective finish.
|Test object with Cosmichrome coating|
“It turned out beautifully,” said Tom, who mounted the chromed trophy to a black wooden plaque and attached a brushed metal plate to the base for the winners to sign.
|Team Togo members with trophy|
The one-of-a-kind trophy was presented to Cisco Networking Challenge winners Aled Cuda, Kyle Gusdorf, Jonathan Liu, Jaren Mendelsohn and Nikola Pratte – Team Togo from North Hollywood High School in Los Angeles – at the Cyberpatriot IX National Finals in Baltimore in April.
In researching options for this project, Tom also learned that you can get similar results with a do-it-yourself electroplating kit. The key is to coat your 3D-printed object with a thin layer of graphite paint so it will conduct electricity when it’s in the electroplating bath.
Encouraged by success of our Cisco project, we went on to create trophies for our foundation’s annual fundraising golf tournament. But instead of using the powder printer, which few 3D printing facilities have, we made them with common FDM (fused deposition modeling) printers using some new kinds of plastic filament. In our next post, we’ll explain the post-processing techniques we used to do that.