Portable Classroom Upgrade: Smaller, Cheaper, Faster

[Eric] at MkMe Lab has a dream: to build a cheap, portable system that provides the electronic infrastructure needed to educate kids anywhere in the world. He’s been working on the system for quite a while, and has recently managed to shrink the suitcase-sized system down to a cheaper, smaller form-factor.

The last time we discussed [Eric]’s EduCase project was as part of his Hackaday Prize 2016 entry. There was a lot of skepticism from our readers on the goals of the project, but whatever you think of [Eric]’s motivation, the fact remains that the build is pretty cool. The previous version of the EduCase relied on a Ku-band downlink to receive content from Outernet, and as such needed to stuff a large antenna into the box. That dictated a case in the carry-on luggage size range. The current EduCase is a much slimmed-down affair that relies on an L-band link from the Inmarsat satellites, with a much smaller patch antenna. A low-noise amp and SDR receiver complete the downlink, and a Raspberry Pi provides the UI. [Eric]’s build is just a prototype at this point, but we’re looking forward to seeing everything stuffed into that small Pelican case.

Yes, Outernet is curated content, and so it’s not at all the same experience as the web. But for the right use case, this little package might just do the job. And with a BOM that rings up at $100, the price is right for experimenting.

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Ottawa Maker Faire - Droids and Pick and Place Machines

Ottawa Maker Faire: Droids And Pick And Place Machines

Three things that I love about participating in Maker Faires are seeing all the awesome stuff people have done over the past year, spending time with all my maker friends in one big room over two days and the reactions to what I made. The 2016 Ottawa Maker Faire had all this in spades.

BB-8 – Droid With Magnetic Personality

There’s just something about BB-8 that touches people. I once heard of a study that showed that when buying kid’s toys, adults were attracted to circles, that that’s the reason teddy bears often have round heads with big round eyes. Similar reactions seem to happen with BB-8, the droid from last year’s Star Wars movie. Adults and kids alike pet him, talk baby-talk to him, and call to him with delight in their voice. I got those reactions all throughout the Maker Faire.

But my favorite reaction happened every time I removed the head and lifted the top hemisphere of the ball to expose the electronics inside. Without fail the reaction of adults was one of surprise. I don’t know if it was because of the complexity of the mechanism that was revealed or because it was just more than they expected. To those whom I thought would understand, I gave the same speech:

“This is the remote control receiver taken from a toy truck, which puts out negative and positive voltages for the different directions. That goes to this ugly hack of a board I came up with that converts it all to positive voltages for the Arduino. The Arduino then does pulse width modulation to these H-bridge driver boards, for speed control, which then talk to these two drill motors.”

Bowie and BB-8
Bowie and BB-8

Those I wasn’t sure would understand were given a simpler overview. Mine’s a hamster drive (we previously covered all the possible ways to drive a BB-8) and so I showed how it sits on two Rollerblade wheels inside the ball. I then flipped it over to show the heavy drill batteries underneath, and then explained how the magnets at the top of the drive mechanism attracted the magnets under the head, which got another look of revelation. All went away satisfied.

But BB-8 sometimes needs a break from human interaction and seeks out its own kind, like Bowie which you can read about below along with more awesome Maker Faire exhibits.

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Hackaday Prize Entry: 3D Prints For The Visually Impaired

Students with visual impairments can have difficulty with visual and spatial relationships. 3D printers can print almost everything, and with a lot of CAD work, this project in the Hackaday Prize provides these students with physical objects to learn any subject.

[Joan] and [Whosawhatsis] have already written the book on 3D printed science projects and have produced a 3D printed Braille map of a campus, but for this project, they’re making things a little bit simpler. Visually impaired students are tactile learners and the simplest of their 3D printable objects are fixed volume objects. This collection of 3D printable cylinders, cones, prisms, and pyramids give a physical representation of geometric solids. These objects also have another trick up their sleeve: they all contain the same volume. Fill the cylinder up with water, pour that water into a cone, and the student will discover that they all contain the same volume.  That’s useful for the visually impaired, but would also put these printable shapes at home in any elementary or middle school math class.

This project already has a rather large following, with teachers of the visually impaired contributing on a Google Group, and a ton of people downloading the models. [Joan] and [Whosawhatsis] are getting a lot of great feedback and growing the range of contributors, making this the start of an awesome community and a great Hackaday Prize entry.

Feel Better About Yourself With These Ugly Repairs

A fun thread over at the EEVblog forum starts off with [TerraHertz]’s triangle-peg, square-hole capacitor repair job and goes entertainingly down-hill from there.

Everything from horrifying eBay purchases to work (horror) stories can be found in this thread. But you can learn something too. Did you know the correct way to fix a mercury switch stored in the incorrect orientation is to whack it against a table really hard?

We enjoyed the cigarette box shroud used to fix a graphics card with a defective fan. We’re still not sure about the person who managed to Dremel bits off a graphics card and end up with a working PCI-e card. That one may be a troll.

Regardless, it’s a lot of fun, spanning the hilariously bad and the seriously impressive. We would not be surprised if some of these people met the devil at the crossroads for some soldering skill. Do any of you have an interesting or ugly repair to share? We’d love to see it.

Portable Lightweight Foundry

[Makercise] is getting ready for Maker Faire. One of the things he’d really like to do is some casting demonstrations. However, he has no desire to take his expensive and heavy electric kiln based foundry to Maker Faire. So, he made his own.

He got into metal casting during his excellent work on his Gingery lathe series. He started off by modeling his plan in Fusion 360. He’d use a 16qt cook pot turned upside down as the body for his foundry. The top would be lined with ceramic fiber insulation and the lid made out of foundry cement. He uses a Reil style burner, which he also modeled as an exercise. This design is light and even better, allows him to lift the top of foundry off, leaving the crucible completely exposed for easy removal.

All went well with the first iteration. He moved the handles from the top to the bottom of the pot and filled it with insulation. He built legs for the lid and made a nice refractory cement bowl on the bottom. However, when he fired it up the bowl completely cracked along with his crucible. The bowl from design flaw, the crucible from age.

A bit put off, but determined to continue, he moved forward in a different direction. The ceramic insulation was doing so well for the top of the foundry that he decided to get rid of the cement altogether and line the bottom with it as well. The lid, however, would be pretty bad for this, so he purchased another pot and cut the top portion of it off, giving him a steel bowl that matched the top.

The foundry fires up and has worked well through multiple pours. He made some interesting objects to hopefully sell at Makerfaire and to test the demonstrations he has planned. The final foundry weighs in at a mere 15lbs not including the fuel cylinder, which is pretty dang light. Video after the break.

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Hoverchair For Your Hoverboard Turns Your Segway Into A Go-Kart

Want to get somewhere safely, but all you have is a Segway? An afternoon spent tinkering can turn your Segway into a lounging cruiser with this hoverseat attachment, just like YouTuber [Inflatable Boats]’s hot new ride.

The backbone of the cart is the Segway Mini Pro. An aluminium frame attaches to the Segway via an eye-bolt and two carabiners, the larger of which has some tape wrapped around it to reduce wear. A swivel caster is attached with u-bolts to support the weight  of the rider along the middle of this makeshift go-cart. Pushing on a t-handle made of pvc — connected to the Segway’s knee brace with a simple strap — engages the motor in lieu of the normal lean-to-go-forward action. Turning is simply done by swinging the handle or pressing with your feet.

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Hackaday Prize Entry: A CNC Plasma Table

CNC routers and 3D printers are cool, but the last time I checked, cars and heavy machinery aren’t made out of wood and plastic. If you want a machine that will build other machines, you want a CNC plasma cutter. That’s [willbaden]’s entry for the Hackaday prize. It’s big, massive, and it’s already cutting.

A plasma CNC machine isn’t that much different from a simple CNC router. [will]’s table controller is just a GRBL shield attached to an Arduino, the bearings were stolen from many copy machines, and your motors and drivers are fairly standard, barring the fact they’re excessively huge for a simple 3D printer.

The real trick up [will]’s sleeve is the controller interface. For this, he’s mounted a Raspberry Pi display, a big, shiny, red button, and all the associated electronics behind a beautifully rusty welded enclosure. This part of the build just sends gcode over to the GRBL shield, and is doing so reliably. Right now [will] is looking for some way to save, arrange, and queue jobs on the Pi, a problem that is almost – but not quite – the same job Octoprint does. A software for big, mean CNCs that spew exotic states of matter is an interesting project, and we can’t wait to see where [will] goes with this one.