3D printing is going to change the world, we’re told. But it sometimes seems that all we can print is useless plastic tat – or perhaps, if you’re lucky, a fiddly replacement bit for the dishwasher.

But a new technique is giving 3D printing the power not just to make new objects, but to augment and repair things we already own. It should make 3D printing far more useful.

To use Encore, a 3D printing system developed by Xiang Chen and his colleagues at Carnegie Mellon University in Pittsburgh, you must first design the new section you want to add to an object. The software then scans the object you want to modify. It analyses the surface geometry and texture to see where additions can be printed. It then prints the desired extra piece on or around the object.


The team has already used Encore to print the housing and components of a torch around a 9-volt battery, mount a plastic teddy bear on a fridge magnet, to print a handle on a coffee cup and a holder for a four-pack of cans.

Instead of ushering in a world of endless, cheap replacements for our stuff, 3D printing systems like Encore may help us extend the value of the things we already own.

“I think people have long been frustrated that every time we start a 3D printing job we always have to start from scratch,” says Chen.

Patch it up

A similar project from Stefanie Mueller and her colleagues at the Hasso Plattner Institute in Potsdam, Germany, takes the idea a step further. As well as adding to existing objects, it can mill away redundant sections of an object, then print an updated design in its place.

Mueller’s team has used the system to print a new mounting for a smartphone when the old one broke, and to change the mount to fit a larger phone when the phone was upgraded.

“3D printing is on the verge of becoming a mass-market,” says Mueller. Technology analysis company Gartner estimates that about 250,000 consumer printers will be sold in 2015, up from just 35,000 in 2012, but projects that more than a million will be sold in 2017.

Repairing and augmenting, rather than printing a whole new object, saves material and energy. “Since only a fraction of the entire object is refabricated, our approach reduces material consumption and plastic waste,” Mueller and her colleagues write in a paper due to be presented next week at Symposium on User Interface Software and Technology (UIST) in Charlotte, North Carolina.

“Everyone will own a 3D printer in the future, once we have solved the challenges,” says Mueller. “While we are very excited about this future evolution, we are also worried about the potential implications on society, such as sustainability.

“Patching a physical object instead of reprinting it from scratch is a first step towards more sustainable 3D printing.”

Image credit: Xiang Chen