Details: To celebrate what would have been Alan Turing's 100th birthday, the Centrum Wiskunde & Informatica (CWI) in Amsterdam ran an exhibition of his work and influence through October 6th, 2012. One of the more abstract ideas, the Turing Machine, was brought to life through LEGO Mindstorms for this exhibit.
If you want to build your own (perhaps with a longer tape), there aren't building instructions (although you can probably figure much of it out from the photos and video), but the full source code is on GitHub.
Details: You may remember having seen this builder's difference engine some years back, but he now has another viral hit and fantastic mechanical computing model working its way across "teh intarwebs". This time he has taken on reproducing the Antikythera Mechanism, an ancient device that predicts eclipses. Discovered off the coast of Antikythera over a hundred years ago, the mechanism appears to have accurately calculated the locations of planets, the moon, and the sun - all based on a date input provided by a hand crank. For more information on the original machine, see the research website and this article in Nature.
Since the original mechanism was rather damaged when it was found, replicating the original gearing exactly wasn't really an option (nevermind the limitations in how many sizes of gears LEGO actually makes...) - so this machine is as close as possible to the original math, but features different actual gearing. More specifically, rather than very precise bronze gears, the exact ratios needed to get the calculations right are handled by differentials. Normally, when you see differentials used in a mechanical computer, they're being used to average two input speeds. That's not the case here. You'll need to look at the original webpage to fully understand exactly what was done here instead, and how that enabled the more advanced gear ratios necessary here. If tomorrow's LMOTD is late, it's probably because I'm still studying the details of this one.
Details: I've previously featured Sariel's first "hand" model, but he has now created a second one. This one makes use of the WeDo Educational Software. LEGO WeDo is only sold through the LEGO company's educational division (see http://www.legoeducation.us/store/), and is designed to work directly with the Power Functions motor system. A USB hub allows a computer to directly control two of the PF motors. Up to 3 hubs can be controlled with the off-the-shelf software, and 2 hubs were used for this particular model. One motor controls the pneumatic hand itself and the pneumatic compressor for that hand, using an autovalve. Two more motors are used for the turntables (one per turntable) to power the wrist and the base of the arm. The fourth motor controls the elevation of the hand through a linkage that does not tilt the hand. Software-wise, there's a task programmed for the arm and the ability to use the keyboard to control the motors individually.
Details: I know I've featured globes before (for some reason the regular search feature here can't find them, but mine as a blog author turns them up here and here, and for some reason a search doesn't turn up the globe tag), but this one is a bit more accurate - it was painstakingly designed with an atlas and a CAD program. As a studs-up ball with brick height (instead of plate height) resolution, it's already a reasonably complex model, but plates and bricks in various colors give the Earth a surprising amount of texture.
Bram's Sphere Generator - tool that allows you to decide all the specifics of a sphere's dimension, and then creates a LDRAW file that shows how to build it with plates in a studs-not-on-top fashion.
Less immediately useful but a bit more convenient for those of us with no studs-not-on-top parts to spare is Timothy P. Smith's Lego Sphere Generator, which also generates output in LDRAW format. This is all studs-up, and the CAD file uses only 1x1 plates.
Another exciting option is LSculpt, which can create studs-out-in-all-directions plans for any shape at all.
There is one more option listed in that 1000steine post I linked to above, but I'd prefer not to recommend expensive software sold on a license basis (all of the options I've listed above are free). (yes, this is in place of a model today - just thought I'd change things up a little)
Details: OK, so scanners have been done with the older Mindstorms RCX units before, but look! NXT! Color! This one is awesome. The resolution isn't particularly great, but you can use Bluetooth to move the images immediately from the NXT's programmable brick to the full-size computer. Come to think of it, I think that the RCX-based scanner I saw was actually just part of a copy machine where it scanned an image with one RCX and then told a second RCX to place the pen in the dark spots. Anyway - this is an excellent model, and there are instructions, photos, details, more video, and programs available at the website above.
Details: For the March 7th, 2006 issue of PC Magazine, the computer magazine hired professional LEGO® artist/sculptor Nathan Sawaya to build a computer sculpture. They wanted to play up the whimsy element of a normal object made out of LEGO® bricks, so bright colors were chosen as the color palette. The final result is, as you can see, quite brilliant. I don't know why green was picked for that keyboard, though. Some plates and special parts were used to make the shapes and ports look fairly realistic. The pixelated effect on the screen is a nice touch - but is that there to show that it's a digital item, or to show that it's made out of LEGO® bricks?
By the way - the site above mentions something about a time lapse video of the building of the CPU part of this sculpture. I wasn't able to find the graphic to link it, but if somebody spots it, let me know.
