3D printers are amazing tools: design an object on your computer, hit control-P, and when you come back from lunch, a nice warm plastic part is waiting for you. For a few years now, I’ve been making prototype plastic parts on a trusty
Stratasys Dimension. It’s quick and makes robust ABS parts at the touch of a button: I just draw in Solidworks and usually have a finished part the next day. But at the scale of parts for the robotic construction kit that we’re working on, we’ve run up against a resolution wall. The Dimension, with a resolution of about 178 microns, just can’t print print the fine details I need at this stage of design.
Enter the
Objet Eden. It’s different technology; the material is deposited by a bunch of print heads in parallel, much more like an inkjet printer than the “hot glue gun on a robot” style of FDM. And the parts are beautiful. Layers are only 16 microns (16 microns!) thick, so parts are smooth to the touch, even shiny, when they come out. The picture above is a test print of a 40mm cube, and it’s perfectly smooth; no ridges or bumps. It’s fast, too — these parts printed in 80 minutes. The material seems strong and durable, and the support material washes off with water. The only catch is that the machine costs about $115,000.
Educational robotics is a mess. There are a bunch of different platforms, and teaching materials can be ad-hoc. The contests have been successful but the First people don’t talk to the Botball people. That’s why we’re pleased that iRobot has started putting together SPARK, an educational resource site for teachers and students. They’re collecting information and activities and trying to start a lively educational robotics community.
It’s nice to see Modular Robotics listed up there next to heavyweights like LEGO and VEX. Thanks, iRobot, for developing an inclusive community site dedicated to improving educational robotics. 
I was skeptical. $0.99 for a charger with free shipping? But the seller had 1,377,576 feedbacks with a 99.7% success rate. Anyway, what did I have to lose; ninety-nine cents? But two days later the charger you see above arrived at my door and I’m pleased to report that it works swimmingly.
Truthfully, though, I don’t understand how this can happen. I’m currently spending a lot of time and energy trying to reduce the cost of our robots, and while I can imagine being able to make this charger so that it sells for $0.99, I have no idea how they can ship it to me (from CA to NY!) for free. It began its journey with DHL and then was transferred to the US Postal Service, so I’m not even sure where it originated from. Shenzhen? 
Our roBlocks prototype (above) uses seven tiny magnets on each face of each cube. On each connector, there are protruding keys (with silver cylinder magnets) and recessed keys (with gold cube magnets). When you put two blocks together, the cylinders (polarized N) attract the cubes (polarized S) and (click!) the magnetic attraction force holds them together. Little magnets are expensive, though, and can also be dangerous if little kids can get their hands on them. So we’re thinking about replacing the recessed magnets with regular old steel, but I had a hard time figuring out how this would effect the magnetic attraction force. Would it reduce it by 50% since we’re eliminating one magnet? Would it be the same since the single magnet induces poles in the steel? I asked some of the engineers in my lab and they had answers as varied as mine. I even called my friend Pete who’s an astrophysicist at a Lawrence Livermore, but that just led to a lot of mumbling and Greek letters. Finally, I broke down and called 
Last weekend I got to play with an amazing group of people at a two day workshop in Boston. It was called 
It turns out I really had no idea how things are made! We just spent a week in Shenzhen and Guanzhou, two manufacturing cities close to Hong Kong. This is where our shoelaces, iPods, dog toys, cameras, T-shirts, bicycles, and laptops come from. We toured a bunch of different factories and tried to understand firsthand what it means to make the decision to mass-produce a piece of consumer electronics. We were only allowed to see the best (in the human rights and environmental sense) factories, but it was an eye opener how much manual labor is involved in production. This disposable cap on my water bottle was probably directly handled by six different people before it was packed to ship. One of the best parts of the trip was getting to spend some time with the amazing people in our group. Many more photos and videos on their blogs and flickrs:
I’m at the National Science Foundation in Washington, DC for the annual Emerging Frontiers in Research and Innovation meeting. 
