Here's more from Made in Space, which is building the 3D printer:
Made in Space delivered their proprietary prototype technology to MSFC on June 17th after passing microgravity tests at Houston’s Johnson Space Center earlier that month. The Engineering Test Unit (ETU) printer, whose design was accomplished in a six month Critical Design Phase (CDP), was subjected to rigorous environmental and functional testing. The results confirmed that the hardware design would survive launch and function in microgravity.
Simulated launch conditions were produced at NASA MSFC to ensure vibrational compliance. The battery of tests also included electromagnetic interference (EMI), acoustic and MSG integration verification. In each case the printer passed all significant tests. Additionally, the fit check indicated no issues with how printer hardware would integrate with the Microgravity Science Glovebox (MSG).
“Passing these developmental tests on the 3D Print test unit shows that our design strategies and philosophies were well-aimed. Our goal going into Critical Design Review (CDR) was to develop a design for a flight-ready unit. We hit our target,” said [Michael] Snyder [Made in Space's director of R&D].
Next up: testing for the flight unit prototype, which begins August 15.