21 August 2012
MAKE a mistake with your average office printer and the worst that happens is a paper jam and some wasted ink. Do the same with a 3D printer, though, and your newly realised creation – anything from a toy to a key piece of machinery – could crumble the second you start using it. That’s because 3D printers cannot yet check if a digital 3D model will hold together when printed.
“Even when a model looks perfectly fine on your computer, its physical representation after 3D printing might not be structurally sound and it can simply break down,” says Ondrej Stava at Adobe in San Jose, California. Now he and colleagues have developed software that can check whether printed models will resist gravity and rough handling, and fixes them if they can’t.
Their program works out the most probable rest positions for a model, such as standing up or on its side and calculates the effects of gravity for each. It also looks at how the model is likely to be held by looking for its centre of mass and any handles, and then gives it a virtual stress test to see whether it can stand up to a strong grip.
“We then choose the most suitable correction to make sure that objects can safely be printed,” Stava says.
The software can modify the model by thickening narrow parts, hollowing out internal sections or adding supporting struts, while ensuring changes to the overall shape are kept to a minimum. The toughened-up model is sent straight to the printer so no modifications to the printing process are needed.
The team tested the program on a printer that builds objects from plastic, but they plan to improve the software to include multiple materials, such as metal, and give it the ability to test models with moving parts. They presented their work last week at the SIGGRAPH conference in Los Angeles.