A while ago my mother sent me a link to the above video. Apparently it was making the rounds as an example of an amazing new technology, even though this tech has been around for years. Still, if my mother, who last time I checked does not regularly look into rapid prototyping technologies, saw this, it must be fairly popular, so I decided to give it a look.
It shows a guy going to Z Corporation to demo the capabilities of 3D printers. A rep from the company shows him around, explains how the machines work, and shows him some objects that came out of their printers. So far, so good.
Then he asks them to reproduce a crescent wrench. They take a wrench, scan it using a high-precision 3D scanner, and then print a copy of it.
Except they don’t really.
Here’s the thing: I’m very familiar with the technologies used in this video. I know what they can and cannot do. They can indeed scan a wrench into a 3D model with incredible accuracy. They can also print a wrench with moving parts that works well. However, what they cannot do is print the scanned model and expect it to work like the original.
3D scanners, accurate though they might be, cannot see inside a multi-part assembly and discern where the gaps between the parts are. This means that while they did print a fully functional crescent wrench, the model they printed was not the one they scanned in.
Many people noticed this. To his credit, David Kaplan, they guy in the video, posted a response in which he admits to this, explains what happened, takes responsibility, and apologizes. Personally, I suspect that while he does take responsibility, this slight deception was not David’s idea, but rather came out of someone else’s desire for a simple, easy to understand narrative.
Still, it really bugs me when this happens. Both 3D scanning and printing are amazing technologies; one does not need to employ sleight-of-hand to show this. However, when deception is used, even one as minimal as this, it causes people to call into question all the other claims made in the video. Put simply, if they’ll lie about one small thing, they might lie about anything, and their credibility as educators is shot.