Puzzling Out an 80s Puzzle Toy

[Ido Gendel] looks back a time in the 80s when kids would learn by answering the questions to quizzes on their “TOMY Teacher,” or, “Sears Quiz-A-Tron”. There’s a bit of a conundrum with this toy. How did it know which answers were correct. Chip memory of any kind wasn’t the kind of thing you’d sweep into the dust bin if you had extras like it is now; it was expensive.

To use the toy, the child would place the notebook in the plastic frame on the device. They’d open the page with the quiz they would like to take. Printed in the upper left hand corner were three colored squares. There was a matching set of colored buttons on the device. They’d press the corresponding buttons in order from top to bottom and then the machine would magically know which answers on the quiz were correct.

[Ido] wondered how the machine handled this information. Was there an internal table for all 27 possible codes? Did it generate the answer table somehow? He sat down with a spreadsheet filled with the notebook code on the left and the corresponding correct answers on the right. Next he stared at the numbers.

He eventually determined that there was a pattern. The machine was using the colored squares as the input for a function that determined what the answers were. A table would have only taken up 68 bytes, but with one 80s chip on board, sounds to play, and lights to switch on and off, the machine needed all the free space it could get.

Wireless Robotic Gripper With Haptic Feedback

We’re not sure what kind of, “High School,” [Sam Baumgarten] and [Graham Hughes] go to that gave them the tools to execute their robotic gripper so well. We do know that it was not like ours. Apparently some high schools have SLS 3D printers and Solidworks. Rather than a grumpy shop teacher with three fingers who, despite that, kept taking the safety off the table saws and taught drafting on boards with so many phalluses and names carved into the linoleum, half the challenge was not transferring them to the line work.

Our bitterness aside, [Sam] and [Graham] built a pretty dang impressive robotic gripper. In fact, after stalking [Sam]’s linkedin to figure out if he was the teacher or the student, (student) we decided they’re bright enough they could probably have built it out of scraps in a cave. Just like [HomoFaciens], and Ironman.

The gripper itself is three large hobby servos joined to the fingers with a linkage, all 3D printed. The mechanical fingers have force sensors at the contact points and the control glove has tiny vibrating motors at the fingertips. When the force of the grip goes up the motors vibrate more strongly, providing useful feedback. In the video below you can see them performing quite a bunch of fairly fine motor skills with the gripper.

The gripper is mounted on a pole with some abrasive tape, the kind found on skateboard decks. At the back of the pole, the electronics and batteries live inside a project box. This provides a counterbalance to the weight of the hand.

The control glove has flexible resistors on the backs of the fingers. The signal from these are processed by an Arduino which transmits to its  partner arduino in the gipper via an Xbee module.

[Sam] and [Graham] did a great job. They worked through all the design stages seen in professional work today. Starting with a napkin sketch they moved onto digital prototyping and finally ended up with an assembly that worked as planned. A video after the break explaining how it works along with a demo video.

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One Man’s Journey To Build Portable Concrete 3D Printer Produces Its First Tiny House

[Alex Le Roux] want to 3D print houses.  Rather than all the trouble we go through now, the contractor would make a foundation, set-up the 3D printer, feed it concrete, and go to lunch.

It’s by no means the first concrete printer we’ve covered, but the progress he’s made is really interesting. It also doesn’t hurt that he’s claimed to make the first livable structure in the United States. We’re not qualified to verify that statement, maybe a reader can help out, but that’s pretty cool!

The printer is a very scaled gantry system. To avoid having an extremely heavy frame, the eventual design assumes that the concrete will be pumped up to the extruder; for now he is just shoveling it into a funnel as the printer needs it. The extruder appears to be auger based, pushing concrete out of a nozzle. The gantry contains the X and Z. It rides on rails pinned to the ground which function as the Y. This is a good solution that will jive well with most of the skills that construction workers already have.

Having a look inside the controls box we can see that it’s a RAMPS board with the step and direction outputs fed into larger stepper drivers, the laptop is even running pronterface. It seems like he is generating his STLs with Sketch-Up.

[Alex] is working on version three of his printer. He’s also looking for people who would like a small house printed. We assume it’s pretty hard to test the printer after you’ve filled your yard with tiny houses. If you’d like one get in touch with him via the email on his page. His next goal is to print a fully up to code house in Michigan. We’ll certainly be following [Alex]’s tumblr to see what kind of progress he makes next!

Ghostbuster Proton Pack Made from Everything

[John Fin] put a lot of work into his Ghostbuster’s proton pack prop with full-featured user control and effects. What appealed to us well beyond the exquisite build is the extra effort taken to write down the whole process in a PDF for anyone wishing to imitate him.

Mr. Fusion is just a Krups Coffee Grinder. Also, Santa isn't real.
Mr. Fusion is just a Krups Coffee Grinder. Also, Santa isn’t real.

We all know that a lot of famous props are creatively rearranged household items. The famous Mr. Fusion from Back to The Future is actually a Krups coffee grinder with some logos adhered.

[John]’s prop is no different. The cyclotron is a five gallon bucket. A garlic powder container fills another function. As you look at it more and more items can be picked out. Is that a spark plug wire? The handles on that are suspiciously similar to a power tool case’s. It all comes together, and while it’s not screen accurate you’d have to be an extreme prop fanatic to tell.

Naturally, the core of [John]’s prop is an Arduino. It stores the sound files on a SD Card shield. It controls all the lights sounds and motors on the prop. This isn’t quite a point and shoot. You must toggle on the power, generator, and arming mechanisms before actually firing. If you do it out of order, the electronics will issue an alarm as warning, and each step in the process has its own unique audio and animated lighting.

Since the Proton Pack went so well, he also built a PKE meter and Ghost Trap to go along with his backpack. He’s ready to take on Vigo at anytime. You can see a video of his prop in action after the break.

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The Politest Patent Discussion, OSHW v. Patents

We’ve covered [Vijay] refreshable braille display before. Reader, [zakqwy] pointed us to an interesting event that occured in the discussion of its Hackaday.io project page.

[Vijay] was inspired by the work of [Paul D’souza], who he met at Makerfaire Bangalore. [Paul] came up with a way to make a refreshable braille display using small pager motors. [Vijay] saw the light, and also felt that he could make the vibrating motor display in such a way that anyone could make it for themselves at a low cost.

Of course, [Paul], had patented his work, and in this case rightly so. As jaded as we have become with insane patent trolls, our expectation on receiving the tip was that [Paul] had sued [Vijay] out of house and home and kicked his dog while he was at it. A short google search shows that [Paul] is no patent troll, and is a leader in his field. He has done a lot to help the visually impaired with his research and inventions.

Instead we were greeted by a completely different conversation. [Paul] politely mentioned that his lawyer informed him that in order to protect his IP he needed to let [Vijay] know exactly how the information could be used. No cease and desist, in fact he encouraged [Vijay] to continue his open research as long as he made it clear that the methods described could not be used to make a marketable product without infringing on [Paul]’s patents. They’d need to get in touch with [Paul] and work something out before doing such.

[Vijay] responded very well to this information. His original goal was to produce a cheap braille display that could be made and sold by anyone. However, he did use [Paul]’s work as a basis for his variation. Since [Paul]’s commercial interests relied on his patent, there was a clear conflict, and it became obvious to [Vijay] that if he wanted to meet his goal he’d have to pick a new direction. So, he released his old designs as Creative Commons, since the CERN license he was using was invalidated by [Paul]’s patent. He made it very clear that anyone basing their work off those designs would have to get in touch with [Paul]. Undaunted by this, and still passionate about the project, [Vijay] has decided to start from scratch and see if he can invent an entirely new, unprotected mechanism.

Yes, the patent system is actually encouraging innovation by documenting prior work while protecting commercial and time investments of beneficial inventors. Well. That’s unexpected.

Kudos to [Paul] for encouraging the exploration of home hackers rather than playing the part of the evil patent owner we’ve all come to expect from these stories. Also [Vijay], for acting maturely to [Paul]’s polite request and not ceasing his work.

Reverse Engineering the McDonald’s French Fry

McDonald’s is serious about their fries. When they were forced by shifting public opinion (drunkenly swaggering around as it always does) to switch from their beef tallow and cottonseed oil mixture to a vegetable oil mixture; they spent millions to find a solution that retained the taste. How they make the fries is not the worlds most closely guarded secret, but they do have a unique flavor, texture, and appearance which is a product of lots of large scale industrial processes. [J. Kenji López-Alt] decided to reverse engineer the process.

His first problem was of procurement. He could easily buy cooked fries, but he needed the frozen fries from McDonald’s to begin his reverse engineering. McDonald’s refused to sell him uncooked fries, “They just don’t do that,” one employee informed him. He reached out to his audience, and one of them had access to a charlatan. The mountebank made quick work of the McDonald’s employees and soon [J. Kenji] had a few bags of the frozen potato slivers to work with.

What follows next was both entertaining and informative. At one point he actually brought out a Starrett dial caliper to measure the fries; they were 0.25in squares in cross section. Lots of research and experimentation was done to get that texture. For example, McDonald’s fries aren’t just frozen raw potatoes. They are, in fact; blanched, flash fried, frozen and then fried again. Getting this process right was a challenge, but he arrived at similar fries by employing his sous vide cooker.

He then wanted to see if he could come up with a french fry recipe that not only allowed the home chef to make their own McDonald’s fries, but improve on them as well. It gets into some food chemistry here. For example he found that the same effect as blanching could be produced by boiling the fries; if you added vinegar to keep the cell walls from disintegrating.

The article certainly shows how knowledge of the chemistry behind cooking can improve the results.

Minecraft Trojan Horse Teaches Kids to Love Electronics and Code

Kids love Minecraft, and a clever educator can leverage that love to teach some very practical skills. The summer class offered by the Children’s Museum in Bozeman Montana would have blown my mind if such a thing existed when we were younger. (Rather than begging one of the dads in my Boy Scout Troop to pirate Visual Studio for me, which was delivered in the form of an alarmingly tall stack of CDs.) The kids in Bozeman get to learn hardware, software, their integration, and all while playing Minecraft.

Minecraft is an immersive universe that has proven to suck in creative minds. It’s the bait that pulls the kids into the summer class but Serialcraft delivers on making the learning just as addictive. This is accomplished by providing students with physical objects that are tied to the Minecraft world in meaningful ways we just haven’t seen before (at least not all at one time). On the surface this adds physical LEDs, toggle switches, potentiometers, and joysticks to the game. But the physical controls invite understanding of the mechanisms themselves, and they’re intertwined in exciting ways, through command blocks and other in-game components that feel intuitive to the students. From their understanding of the game’s mechanics they understand the physical objects and immediately want to experiment with them in the same way they would new blocks in the game.

The thing that makes this magic possible is a Minecraft mod written by [John Allwine], who gave us a demonstration of the integration at Maker Faire Bay Area 2016. The mod allows the user to access the inputs and output of the Arduino, in this case a Pololu A-Star 32U4, from within Minecraft. For the class this is all packaged nicely in the form of a laser cut controller. It has some LEDs, two joysticks, buttons, potentiometers, and a photosensor.

As you can see in the video below the break, it’s really cool. The kids have a great time with it too. For example, [John] showed them how they can attach their unique controller to a piston in the world. Since this piston can be controlled by them alone, they quickly figured out how to make secret safe rooms for their items.

Another troublesome discovery, was that the photo transistor on the controller set the light level in the game world by altering the time of day. Kids would occasionally get up and change the world from day to night, by turning the lights in the room on or off. A feature that has a certain appeal for any Minecraft player, is rigging one of the LEDs on the controller to change brightness depending on proximity to a creeper.

There’s a lot more to the library, which is available on GitHub. The kids (and adults) have a great time learning to link the real world with the world’s most accessible fantasy world creation kit.  Great work [John]!

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