Post-Processing Tips for 3D Printing Trophies: Part 2

Whether they’re Oscar statuettes, youth sports participation awards or anything in between, we tend to think of trophies as shiny metallic objects. But there’s no rule that says they have to be gleaming silver or gold, especially if you’re making them with a 3D printer.

In Part 1 of this post, we shared methods for giving 3D-printed trophies a finish that looks like chrome plating. Now, let’s explore a different approach to post-processing for plastic pieces made with FDM (fused deposition modeling) printers.

After successfully completing our Cisco trophy, we decided to create small trophies for each member of the winning team at our annual fundraising golf tournament. Our Director of Instruction, Tom Meeks, came up with as design featuring a golf ball atop a cylindrical base. And instead of the standard metal-plated finish, Tom wanted the ball to be white – like a real golf ball – and the base to look like wood. 

Finished trophies for YouthQuest's golf tournament

We had initially ruled out using FDM machines for the project because, even when they’re set for the finest detail, the printing process always leaves visible striations as layers of melted filament are stacked up. We wanted to create plastic parts with smooth surfaces – and do it with a minimum amount of effort.

One popular method is sanding the piece and brushing on an epoxy product such as XTC-3D or, for plastics like ABS, Acetone. But that can be time-consuming, mixing the epoxy can be messy and Acetone is potentially dangerous to you and your print if you’re not careful.

Tom’s search for a better solution led him to discover Polymaker. The company makes a PVB filament called PolySmooth, which prints like PLA, but can be smoothed with ethanol or isopropyl alcohol. Post-processing is done by putting prints in the Polysher, a device that generates an alcohol mist inside a see-through tank. Print layer lines virtually disappear, leaving a surface that looks polished – exactly what we wanted for our “golf ball.”

Ball after smoothing in Polysher

To print the base, we could have used any number of filaments made with a mixture of wood and thermoplastic, but they tend to cause extruder clogs. Instead we went with Polymaker’s PolyWood, which doesn’t contain any wood particles but looks and feels much like genuine wood, and can be textured and stained just like the real thing.

Trophy base made of PolyWood before staining

Having filament that’s affected by alcohol also opens up some interesting possibilities for adding colors to 3D printed pieces in post-processing. Tom had been experimenting with the Craftwell eBrush, an electric airbrushing system that uses alcohol-based color makers, before he learned about PolySmooth filament. He’s planning to have our advanced 3D ThinkLink students try using the eBrush on PolySmooth parts to see what kind of results they can produce during our next Immersion Lab Week.

   

Post-Processing Tips for 3D Printing Trophies: Part 1

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.