Paint The Rainbow With This Skittle-Dropping Pixel Art Robot

July 12, 2019 by Dan Maloney 7 Comments

We hackers just can’t get enough of sorters for confections like Skittles and M&Ms, the latter clearly being the superior candy in terms of both sorting and snackability. Sorting isn’t just about taking a hopper of every color and making neat monochromatic piles, though. [JohnO3] noticed that all those colorful candies would make dandy pixel art, so he built a bot to build up images a Skittle at a time.

Dubbed the “Pixel8R” after the eight colors in a regulation bag of Skittles, the machine is a largish affair with hoppers for each color up top and a “canvas” below with Skittle-sized channels and a clear acrylic cover. The hoppers each have a rotating disc with a hole to meter a single Skittle at a time into a funnel which is connected to a tube that moves along the top of the canvas one column at a time. [JohnO3] has developed a software toolchain to go from image files to Skittles using GIMP and a Python script, and the image builds up a row at a time until 2,760 Skittle-pixels have been placed.

The downside: sorting the Skittles into the hoppers. [JohnO3] does this manually now, but we’d love to see a sorter like this one sitting up above the hoppers. Or, he could switch to M&Ms and order single color bags. But where’s the fun in that?

[via r/arduino]

A Guide To Shop Equipment Nobody Thinks About: Clean, Organized, And Efficient

July 7, 2019 by Tom Nardi 27 Comments

When planning out a workspace at home, the job, or at a makerspace, we all tend to focus on the fun parts. Where the equipment will go, how you’ll power it, what kind of lights you’ll get, etc, etc. It’s easy to devote all your attention to these high-level concepts, which often means the little details end up getting addressed on the fly. If they get addressed at all.

But whether we want to admit it or not, an organized workspace tends to be more efficient. That’s why [Eric Weinhoffer] has put together a blog post that details all those mundane details that we tend to forget about. It’s not exactly exciting stuff, and contains precisely as much discussion about whiteboards as you probably expect. That said, it’s thorough and clearly comes from folks who’ve had more than a little experience with setting up an efficient shop.

So what’s the first thing most shops don’t have enough of? Labels. [Eric] says you should put labels on everything, parts bins, tools, machines, if it’s something you need to keep track of, then stick a label on it. This does mean you’ll likely have to buy a label maker, but hey, at least that means a new gadget to play with.

Of course, those self-stick labels don’t work on everything. That’s why [Eric] always has a few rolls of masking tape (such as the blue 3M tape you might be using on your 3D printer bed) and some quality markers on hand to make arbitrary labels. Apparently there’s even such a thing as dry erase tape, which lets you throw an impromptu writing surface anywhere you want.

[Eric] also suggests investing in some collapsible cardboard bins which can be broken down and stored flat when not in use. If you’ve got the kind of situation where you’ll always have more or less the same amount of stuff then plastic is probably your best bet, but in a more dynamic environment, being able to collapse the bins when they aren’t in use is a capability we never even realized we needed until now.

As you might imagine, the post also touches on the issues of keeping sufficient safety gear available. We’ve talked about this in the past, but it’s one of those things that really can’t be said too many times. Having a wall of meticulously labeled storage bins is great, but it’s going to be the last thing on your mind if you manage to get an eye full of superglue.

Locking Up Lock Washers

July 3, 2019 by Al Williams 41 Comments

We’ll admit most of us are more comfortable with solder and software than mechanical things. However, between robots, 3D printers, and various other mechanical devices, we sometimes have to dig into springs, belleville washers, and linear actuators. Unless you are a mechanical engineer, you might not realize there’s a lot of nuances to something even as simple as a nut and bolt. How many threads do you need to engage? Do lock washers work? [Engineer Dog] has a post that answers these and many other questions.

The top ten list starts off with something controversial: split ring lock washers don’t work. The original post cites a paper that claims they don’t except in very special circumstances. However, he updated the post later to say that some people disagree with his cited study. In the end, you’ll have to decide, but given there are other options, maybe we’ll start using those more often.

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This MDF Sound Bar Sounds Great

July 3, 2019 by Brian Benchoff 12 Comments

Everyone should build a speaker cabinet at least once in their life, if only so they can realize how much thought goes into building a simple box. [John] of ibuildit.ca wanted a sound bar for his home theater setup, and that means building a sound bar. The result is beautiful, and a demonstration of how much you can do with just a router and a table saw.

[John] built this sound bar almost entirely out of MDF, which isn’t the best material but it works well enough for a speaker cab that’s meant to be mounted to a wall. The sides were constructed first, with a rabbet holding the front and back on. Both the woofer and tweeter are inset into the front, and a standard piece of plumbing pipe serves as the bass port. Slap a round over bit into the router and do some light sanding, and everything looks great with a coat of black paint.

As with any speaker enclosure, the design is effectively parametric, designed entirely around the drivers being used. In this case, [John] is using a spreadsheet named ‘Unibox’ that gives you all the formulas and graphs for designing a speaker enclosure.

With the box built and the speakers installed, the only matter left were a few aesthetic choices. [John] went with a standard black finish with a very nice wooden grille held onto the front with magnets. It’s a design that pops, but the true test of a speaker is how it sounds. That’s a bit hard to convey over the Internet, but [John] included a few sound samples at the end of the build video, available below.

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Ramen Lamp Has Us Feeling Hungry

July 2, 2019 by Lewin Day 7 Comments

Ramen comes in many forms, and whether you’re eating the 10 cent instant packets during the school year, or dining out at a fancy noodle bar, it’s a tasty meal either way. [ramenkingandi] has long been in love with the classic Japanese fare, and decided to create a homage to the dish – in lamp form.

The lamp build begins, somewhat unsurprisingly, with a lamp – but not how you’d think. A Walmart floor lamp is harvested for its lampshade, which approximates the dimensions of a typical ramen bowl. It’s then fitted with warm yellow LEDs to give it a pleasing glow. Polymer clay is used to create fake ramen ingredients – including noodles, pork, and choy sum. Jewelery wire is used to suspend the chopsticks in mid-air, before resin is poured into the bowl and the ingredients arranged on top. For a final touch, the bowl is painted with an artistic stripe to hide the electronics inside, and the lamp is complete.

It’s a great example of fake Japanese food, which is actually a huge industry in that part of the world. We’d love to have this lamp on display in our own home, fully expecting ramen consumption to increase considerably over time.

Lamps are a common feature around these parts – and some of them have even learned to leap.

AI Recognizes And Locks Out Murder Cats

July 1, 2019 by Dan Maloney 56 Comments

Anyone with a cat knows that the little purring ball of fluff in your lap is one tiny step away from turning into a bloodthirsty serial killer. Give kitty half a chance and something small and defenseless is going to meet a slow, painful end. And your little killer is as likely as not to show off its handiwork by bringing home its victim – “Look what I did for you, human! Are you not proud?”

As useful as a murder-cat can be, dragging the bodies home for you to deal with can be – inconvenient. To thwart his adorable serial killer [Metric], Amazon engineer [Ben Hamm] turned to an AI system to lock his prey-laden cat out of the house. [Metric] comes and goes as he pleases through a cat flap, which thanks to a solenoid and an Arduino is now lockable. The decision to block entrance to [Metric] is based on an Amazon AWS DeepLens AI camera, which watches the approach to the cat flap. [Ben] trained three models: one to determine if [Metric] was in the scene, one to determine whether he’s coming or going, and one to see if he’s alone or accompanied by a lifeless friend, in which case he’s locked out for 15 minutes and an automatic donation is made to the Audubon Society – that last bit is pure genius. The video below is a brief but hilarious summary of the project for an audience in Seattle that really seems quite amused by the whole thing.

So your cat isn’t quite the murder fiend that [Metric] is? An RFID-based cat door might suit your needs better.

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Trick Shot Bot Flings Balls Into Wine Glass Every Time

June 26, 2019 by Dan Maloney 7 Comments

We’ve heard of beer pong, but we’re not sure we’ve heard of wine pong. And certainly never wine pong automated with a ping pong ball throwing robot like this one.

There’s not a huge amount of detail available in the video below, and no build log per se. But [Electron Dust] has a few shots in the video that explain what’s going on, as well as a brief description in a reddit thread about the device. The idea is to spin a ball up to a steady speed and release it the same way every time. The rig itself is made of wood and spun by plain brushed DC motors – [Electron Dust] explains that he chose them over PWM servos to simplify things and eliminate uncertainty in the release point. The ball is retained by a pair of arms, each controlled by a pair of hobby servos. An Arduino spins along with everything else and counts 50 revolutions before triggering the servos to retract and release the ball. A glass positioned at the landing spot captures the ball perfectly once everything is dialed in.

Here’s hoping that build details end up on his blog soon, as they did for this audio-feedback juggling machine. And while we certainly like this project, it might be cool if it could aim the ball into the glass. Or it could always reposition the target on the fly.

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