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Wednesday, August 31, 2011

Creating physical objects using 3D printer technology

Sept. 5, 2011
by Mark Ollig


Astronaut and mechanical engineer, Mike Massimo mentioned how cool it would be having a science-fiction replicator, so that a tool used on earth could all of a sudden be made to appear in space.

“But we don’t have that yet,” he said.

What we currently do have might not be exactly like the replicator seen on the TV science fiction series “Star Trek,” but today’s 3D (three-dimensional) printers are getting closer to Massimo’s vision.

I recently watched a 2011 National Geographic video which showed how a crescent wrench was created using a 3D printer manufactured by a company started in 1994, called Z Corporation.

David Kaplan, a theoretical physicist, was covering the story for the National Geographic channel and brought his own crescent wrench to Z Corporation for replicating.

One can think of 3D printing as a process of fitting together loose materials to create a solid object.

It can also be compared to “additive manufacturing technology,” whereby a three-dimensional object is manufactured by placing down repeated layers of material.

The secret ingredient used in this particular 3D replication of a crescent wrench is a specially engineered composite material, which starts out as a powder, and has a binder material added to it, which solidifies the powder particles together to shape a structure.

So think of the powder as the plaster material or paper, and the binder material as an adhesive or the ink.

Inside the 3D printer, there is a print head for the binder materials to solidify the parts.

Another print head inside the 3D printer ejects specific fluids used for coloring different parts.

Joe Titlow, vice president of product management for Z Corporation, showed how an existing object (in this case, a crescent wrench) would normally be scanned into a software program and physically replicated via a 3D printer.

Titlow demonstrated the surface scanning technique on Kaplan’s crescent wrench and showed how the dimensional details of the crescent wrench would be used with a 3D computer-aided design (CAD) and computer-aided manufacturing (CAD) program.

The scanner would measure and send every dimensional aspect of an object into the 3D scanner computer program, which would then create a final 3D image that would be sent to the 3D printer.

The 3D scanner Titlow used in the demonstration was a hand-held device.

Digital editing can be performed on a scanned image before being printed.

An interesting twist to this is when Kaplan wanted to make the adjustable captive worm screw on the crescent wrench the color red. The 3D program designer clicked onto the crescent wrench image’s captive worm screw and then clicked a palette color which made the captive worm screw red.

After visually inspecting the edited 3D image on the screen, Titlow clicked “print” and the words “initiate build” were seen on the computer display screen.

The 3D ZPrinter 650 being used suddenly came to life and began operating.

It started to create a cross-section of the crescent wrench inside the powder – it was printing out a physical crescent wrench.

After the process completed, the newly created and “solidified” crescent wrench lay covered inside a small mound of excess powder particles.

Kaplan reached inside this powder mound with his hand and removed the newly created crescent wrench.

With a look of wonderment on his face, he blew off the excess powder and held up the new crescent wrench in his hand.

It looked very much like the crescent wrench he brought in with him, although the nylon plastic was whiter in color and it had a red captive worm screw.

He then tested the newly manufactured crescent wrench by tightening a bolt, (which I saw him do). Kaplan said on the video that he was able to do this “reasonably well.”

Surprisingly, it was later revealed by Kaplan himself (in a separate video I watched) that when he tried to tighten the bolt as hard as he could, the new crescent wrench manufactured by the 3D printer broke.

Kaplan said he was told there were methods of making a newly made crescent wrench stronger.

He also made it known the scanner used in the demonstration did not scan the internal structure of his crescent wrench.

Kaplan also revealed the crescent wrench he had brought with him was not the actual scanned image used; Z Corporation used an existing 3D software template image of a similar crescent wrench when manufacturing it on the 3D printer.

I can only assume Z Corporation’s existing 3D software template image of a crescent wrench was used to save time from having to edit a newly scanned 3D image of the crescent wrench Kaplan had brought with him.

Kaplan did, however, make it very clear that the new crescent wrench was, in fact, created using the 3D printer.

This is an exciting technology, and we will be hearing more about it.

The demonstration video can be seen at http://tinyurl.com/4yjph96.

A video explaining the 3D ZPrinter 650 can be seen at http://tinyurl.com/3mcj3j5.