Suspension bridges are far and away the target of choice in America’s action blockbusters. In just the past three years, the Golden Gate Bridge has been destroyed by a Kaiju, Godzilla, a Skynet-initiated nuclear blast, and a tsunami. Americans don’t build real bridges anymore, or maintain the ones that we have, but we sure love to blow them up in movies.
There is logic here: A disaster scene involving a famous bridge serves both to root the film in the real world and to demonstrate the enormity and the immediacy of the threat. The unmaking of these huge structures shocks us because many bridges have gained an aura of permanence in our collective consciousness. Although we know when the Brooklyn Bridge was built and who built it, we feel like it has always been there and always will be. The destruction of our familiar human topography is even more disturbing than the deaths of the CGI victims, and I’m not just saying that as a misanthrope who loves bridges.
However, in all of the planning, storyboarding, rendering, and compositing of these special effects shots, nobody pauses to consider how suspension bridges actually behave. I can accept messianic alien orphan superheroes and skyscraper-sized battle robots, but I will not stand for inaccurate portrayals of structural mechanics. It’s fine to bend the laws of physics if the plot warrants it, but most suspension bridge mistakes are so needless and stupid that their only function seems to be irritating engineers.
Continue reading “Suspension Bridges Of Disbelief”
It’s safe to say we’ve hit a bit of a plateau with hobby based 3D printers using FDM technology. Print quality is pretty high, they’re about as fast as they’re going to get, and compared to commercial machines they’re a pretty good bang for your buck. So what’s next? What about printing in color?
It is possible to print in color using a regular 3D printer and a bit of patience, but it’s really not economical or efficient. We’ve seen multiple extruder heads for 3D printing as well, but there are many problems with that due to calibration and trailing plastic from one head to another. So what if you could feed multiple color filaments into a single mixing head?
Well, it turns out you can. Earlier this year RepRap ran a Kickstarter for the development of the Diamond Hotend — a single nozzle multi-color extruder. It’s in production now and appears to work quite well. It’s also compatible with many 3D printers as long as the motherboard has triple extruder support.
However, the big question remains — how do you program a colored print? Using Repetier Host actually. You’ll need to export your 3D model in the .AMF file format, but once you do, you’ll be able to configure it for a color print job inside Repetier Host.
Continue reading “Diamond Hotend Opens The Color Gamut For 3D Printing”
Technology keeps making things smaller, but this is ridiculous. Scientists at Rice University in Houston have just made a tiny submarine with a molecular motor. They call it a unimolecular submersible nanomachine (USN), because it is composed of a single molecule made up of 244 atoms. The really smart bit comes from how it is driven: when the molecule absorbs a photon of light, one of the bonds that holds it together becomes more flexible, and the tail spins a quarter of a rotation to attach to another atom and reach the preferred lower energy state. This motion moves the molecule, and the process repeats. This happens millions of times a second.
I wouldn’t put down a deposit on a nanosub quite yet, though: the motion is random, as there is no way to steer the molecule at present. The researchers figured out that it behaves this way by analyzing the way that the molecule diffuses, because these molecules diffuse 25 per cent quicker with the light source than without. Nope, not very practical, but it is a neat bit of molecular hackery.