MakerBot was poised to be one of the greatest success stories of the open source hardware movement. Founded on the shared knowledge of the RepRap community, they created the first practical desktop 3D printer aimed at consumers over a decade ago. But today, after being bought out by Stratasys and abandoning their open source roots, the company is all but completely absent in the market they helped to create. Cheaper and better printers, some of which built on that same RepRap lineage, have completely taken over in the consumer space; forcing MakerBot to refocus their efforts on professional and educational customers.
This fundamental restructuring of the company is perhaps nowhere more evident than in the recent unveiling of “SKETCH Classroom”: an $1,800 package that includes lesson plans, a teacher certification program, several rolls of filament, and two of the company’s new SKETCH printers. It even includes access to MakerBot Cloud, a new online service that aims to help teachers juggle student’s print jobs between multiple SKETCH printers.
Of course, the biggest takeaway from this announcement for the average Hackaday reader is that MakerBot is releasing new hardware. Their last printer was clearly not designed (or priced) for makers, and even a current-generation Replicator costs more than the entire SKETCH Classroom package. On the surface, it might seem like this is a return to a more reasonable pricing model for MakeBot’s products; something that could even help them regain some of the market share they’ve lost over the years.
There’s only one problem, MakerBot didn’t actually make the SKETCH. This once industry-leading company has now come full-circle, and is using a rebranded printer as the keystone of their push into the educational market. Whether they were unable to build a printer cheap enough to appeal to schools or simply didn’t want to, the message is clear: if you can’t beat them, join them.
As amazing as prosthetic limbs have become, and as life-changing as they can be for the wearer, they’re still far from perfect. Prosthetic hands, for instance, often lack the precise control needed for fine tasks. That’s a problem for [Bertolt Meyer], an electronic musician with a passion for synthesizers with tiny knobs, a problem he solved by hacking his prosthetic arm to control synthesizers with his mind. (Video, embedded below.)
If that sounds overwrought, it’s not; [Bertolt]’s lower arm prosthesis is electromyographically (EMG) controlled through electrodes placed on the skin of his residual limb. In normal use, he can control the servos inside the hand simply by thinking about moving muscles. After experimenting a bit with an old hand, he discovered that the amplifiers in the prosthesis could produce a proportional control signal based on his inputs, and with a little help from synthesizer manufacturer KOMA Electronik, he came up with a circuit that can replace his hand and generate multiple control voltage channels. Plugged into any of the CV jacks on his Eurorack modular synths, he now has direct mind control of his music.
Gears are fairly straightforward way to couple rotational motion, and the physics topics required to understand them are encountered in an entry level physics classroom, not a university degree. But to really dig down to the root of how gears transfer motion may be somewhat more complex than it seems. [Bartosz Ciechanowski] put together an astonishingly good interactive teaching tool on gears, covering the fundamentals of motion up through multi-stage gear trains.
The post starts at the beginning – not “how to calculate a gear ratio” – but how does rotational motion work at all. The illustrations help give the reader an intuitive sense for how the rate of rotation is measured and what that measurement actually represents in the real world. From there [Bartosz] builds up to describing how two discs touching edge to edge transfer motion and the relationship of their size on that process. After explaining torque he has the fundamentals in place to describe why gears have teeth, and why they work at all.
Well written explanatory copy aside, the real joy in this post is the interactivity. Each concept is illustrated, and each illustration is interactive. Images are accompanied by a slider which lets you adjust what’s shown, either changing the speed of a rotating gear or advancing the motion of two teeth interlocking. We found that being able to move through time this way really helped form an intuitive understanding of the concepts being discussed. This feels like the dream of interactive multimedia textbooks come to life.