Ottawa Maker Faire: Droids And Pick And Place Machines

October 22, 2016 by Steven Dufresne 4 Comments

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

Explaining BB-8 at the Ottawa Maker Faire (source: Ottawa Mommy Club)

My BB-8 droid

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.”

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

October 19, 2016 by Brian Benchoff 7 Comments

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.

Fridge Parts Make Air Compressor That’s Easy On The Ears

October 12, 2016 by Dan Maloney 46 Comments

Compressed air is great to have around the shop. The trouble is, most affordable compressors are somewhere between “wake the dead” and “the reason Pete Townshend is deaf” on the decibel scale. But with a little ingenuity and a willingness to compromise on performance, you might find this ultra-quiet, ultra-cheap air compressor a welcome way to keep the peace in your shop.

Yes, this compressor under-performs even a Harbor Freight pancake compressor which can be had for $60 and is ready to work right out of the box. In fact, [Eric Strebel]’s design sort of requires you to buy an air tank, and the easiest way to do that might be just to buy the compressor in the first place. But the off the shelf unit won’t run as quietly as this one does, what with a refrigerator compressor swapped in for the original motor and pump. There’s also a silencer on the input side, fashioned from a shaving cream can and some metal wool. The video below shows the build, and the results are impressive, at least from a noise perspective. Whether it suits your shop depends on your application – it certainly won’t run an impact wrench, but it’ll blow chips off your mill or dust out of your computer.

Fridge compressors are a natural starting point for air compressor builds, like this fire extinguisher based design, or this high-pressure tandem compressor. But if you need high flow and don’t care about the racket, try ganging four HF compressors in parallel.

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Peculiar Fluid Dynamics Creates Hot And Cold Air

October 11, 2016 by Dan Maloney 61 Comments

We’re fascinated by things with no moving parts or active components that work simply by virtue of the shape they contain — think waveguides and resonators for microwave radiation. A similarly mystical device from the pneumatics world is the Hilsch Vortex Tube, and [This Old Tony] decided to explore its mysteries by whipping up a DIY version in his shop.

Invented in the 1930s, vortex tubes are really just hollow tubes with an offset swirl chamber. Incoming compressed air accelerates in the swirl chamber and heads up the periphery of the long end of the tube, gaining energy until it hits a conical nozzle. Some of the outer vortex escapes as hot air, while the rest reflects off the nozzle and heads back down the pipe as a second vortex inside the outer one. The inner vortex loses energy and escapes from the short end as a blast of cold air – down to -50°C in some cases. [Tony]’s build doesn’t quite approach that performance, but he does manage to prove the principle while getting a few good-natured jabs into fellow vloggers [AvE] and [Abom79].

We’ve covered vortex tubes before, but as usual [Tony]’s build shines because he machines everything himself, and because he tries to understand what’s making it work. The FLIR images and the great video quality are a bonus, too.

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Feel Better About Yourself With These Ugly Repairs

October 7, 2016 by Gerrit Coetzee 50 Comments

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.

Tiny Smoothies At Maker Faire

October 5, 2016 by Brian Benchoff 43 Comments

For almost the last decade, desktop 3D printing has, at its heart, been centered around 8-bit microcontrollers. The ATmegas and other Atmel chips are good enough to move a few steppers and squirt some plastic. With faster processors, you get smoother acceleration, leading to better prints. Modern ARM devices have a lot of peripherals, allowing for onboard WiFi and Ethernet connectivity. The future is 32-bit print controllers.

Right now there are a few 32-bit controllers, from the very weird, out-of-nowhere controller for the Monoprice Mini 3D printer to the more traditional SmoothieBoard. Only one of these boards has the open hardware cred for a proper 3D printer controller, and a this year’s Maker Faire, Cohesion3D introduced a few machine control boards built on top of Smoothie that add a few interesting features and techniques.

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Maker Faire Multicolor And Multi Material 3D Printing

October 3, 2016 by Brian Benchoff 25 Comments

The next frontier of desktop 3D printing is multi-material and multi-color prints. Right now, you can buy a dual toolhead for a Lulzbot, and dual toolheads from other companies exist, although they are a bit rare. In the next few years, we’re going to see a lot of printers able to print dissolvable supports and full-color 3D printers.

Printing in more than one color is almost here, but that doesn’t mean we’re on the cusp of a complete revolution. Multi-material printing is lagging a little bit behind; you’ll be able to print two colors of PLA next year, but printing an object in PLA and ABS is going to be a bit tricky. Printing something in PLA and nylon will be very hard. Color mixing, likewise, will be tricky. We can do it, the tools are getting there, but think of this year as a preview of what we’ll be doing in five years.

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