Put A New Spin On Your 3D Printed Parts

May 19, 2022 by Al Williams 4 Comments

Once you get tired of printing keychains and earbud holders with your 3D printer, you’ll want to design things a bit more sophisticated. How about things that rotate? [3DSage] has a good how-to about how to integrate a simple motor and controller into a few different size boxes. Combined with some 3D printed linkages, these boxes can turn your project — printed or otherwise — into something that spins.

To demonstrate, he created a few cat toys, played with an idea for a magic trick, and refit a selfie light into… something. We have no doubt you can find something to do with these little motor modules. The boxes vary mostly in how big the battery packs are. There are also several interesting side pieces like a 3D holder for rechargeable button cells and their charger.

In addition, he also demonstrates how to use the motor as a (rather poor) generator. Attaching a water wheel wasn’t a success until he used compressed air to run the wheel. You would have thought water would have done the trick.

The video stresses that you should solder connections, but you don’t have to. Honestly, we think if you are building moving stuff with a 3D printer, you should probably just go ahead and learn to solder. It isn’t that hard and there are plenty of reasons to learn.

Of course, you could 3D print the motor itself. Adapting motor modules for different uses isn’t a new idea, of course, but it is always great to see more ways to apply basic components.

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Engineering Vs Pigeons

May 19, 2022 by Al Williams 36 Comments

We’ve all been there. Pigeons are generally pretty innocuous, but they do leave a mess. If you have a convertible or a bicycle or even just a clean car, you probably don’t want them hanging around. [Max] was tired of a messy balcony, so like you might approach any engineering problem, he worked his way through several possible solutions. Starting with plastic crows, and naturally ending with an automated water gun.

The resulting robotic water gun that targets pigeons with openCV is a dandy project and while we don’t usually advocate shooting at neighborhood animals, we don’t think a little water will be any worse than the rain for the pigeons. The build started with a cheap electric water pistol. A Wemos D1 Mini ESP8266 development board provides the brainpower. The water pistol wouldn’t easily take rechargeable batteries, plus it is a good idea to separate the logic supply and the pump motors, so the D1 gets power from a USB power bank separate from the gun’s batteries.

That leaves the camera. An old iPhone 6S with a 3D printed bracket feeds video to a Python script that uses openCV. If looks for changes using a very particular algorithm to detect that something is moving and fires the gun. It doesn’t appear that it actually tracks the pigeons, so maybe that’s a thought for version 2.

Was it successful? Maybe, but it does seem like the pigeons learned to avoid it. We still think azimuth and elevation on the gun would help.

Most of the time when we see pigeon hacking it is to use them for nefarious purposes. [Max] should be glad he doesn’t have to deal with lions.

MIDI Controller Looks Good, Enables Your Air Guitar Habit

May 18, 2022 by Al Williams 8 Comments

We all want to be guitar heroes, but most of us have to settle for letting a MIDI board play our riffs using a MIDI controller. [Joris] thinks a MIDI controller should look like a cool instrument and thus the Ni28 was born. Honestly, we first thought we were looking at wall art, but on closer look, you can see the fretboard and the soundhole are festooned with buttons.

Actually, they aren’t really buttons. The Ni in the name is because the buttons are nickel-plated brass plates that act like touch switches. There’s virtually no activation force required and you can easily touch more than one plate at a time.

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The Little Big Dogs Of Invention

May 18, 2022 by Al Williams 53 Comments

This is a story about two dogs I know. It is also a story of the U.S. Navy, aviation, and nuclear weapons. Sometimes it is easy to see things in dogs or other people, but hard to see those same things in ourselves. It’s a good thing that dogs can’t read (that we know of) because this is a bit of an embarrassing story for Doc. He’s a sweet good-natured dog and he’s a rather large labradoodle. He occasionally visits another usually good-natured dog, Rocky — a sheltie who is much smaller than Doc.

I say Rocky is good-natured and with people, he is. But he doesn’t care so much for other dogs. I often suspect he doesn’t realize he’s a dog and he is puzzled by how other dogs behave. You would think that when Doc comes to visit, the big dog would lord it over the little dog, right? Turns out, Doc doesn’t realize he’s way bigger than Rocky and — apparently — Rocky doesn’t realize he should be terrified of Doc. So Rocky bullies Doc to the point of embarrassment. Rocky will block him from the door, for example, and Doc will sit quaking unable to muster the courage to pass the formidable Rocky.

Big Doc…

Somewhat smaller Rocky….

It makes you wonder how many times we could do something except for the fact that we “know” we can’t do it. Or we believe someone who tells us we can’t. Doc could barge right past Rocky if he wanted to and he could also put Rocky in his place. But he doesn’t realize that those things are possible.

You see this a lot in the areas of technology and innovation. Often big advances come from people who don’t know that the experts say something is impossible or they don’t believe them. Case in point: people were anxious to fly around the start of the 1900s. People had dreamed of flying since the dawn of time and it seemed like it might actually be possible. People like Alberto Santos-Dumont, the Wright brothers, Clément Ader, and Gustave Whitehead all have claimed that they were the first to fly. Others like Sir George Cayley, William Henson, Otto Lilienthal, and Octave Chanute were all experimenting with gliders and powered craft even earlier with some success.

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Color(ing) Computer Needs No Batteries

May 18, 2022 by Al Williams 3 Comments

While Radio Shack did have the Color Computer, we don’t think they had this in mind. [Pepepépepe] has some coloring book pages and simple rules that let you simulate logic circuits using a crayon. The downloadable ‘zine has hand-written instructions and several examples.

Keep in mind, this is a computer in the same way the old logic kits in the 1960s were computers. They are really demonstrations of digital logic circuits. To work the “computers”, you pick two colors, one for a square and the other for a circle. You color pathways until you reach a “nory.” The nory, which looks suspiciously like a slingshot with eyes, has a special rule. If both branches of the nory have your circle color on them, the output of the nory will be the square color. Otherwise, the color coming out is the circle color.

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How The IBM PC Went 8-Bit

May 17, 2022 by Al Williams 52 Comments

If you were around when the IBM PC rolled out, two things probably caught you by surprise. One is that the company that made the Selectric put that ridiculous keyboard on it. The other was that it had an 8-bit CPU onboard. It was actually even stranger than that. The PC sported an 8088 which was a 16-bit 8086 stripped down to an 8 bit external bus. You have to wonder what caused that, and [Steven Leibson] has a great post that explains what went down all those years ago.

Before the IBM PC, nearly all personal computers were 8-bit and had 16-bit address buses. Although 64K may have seemed enough for anyone, many realized that was going to be a brick wall fairly soon. So the answer was larger address buses and addressing modes.

Intel knew this and was working on the flagship iAPX 432. This was going to represent a radical departure from the 8080-series CPUs designed from the start for high-level languages like Ada. However, the radical design took longer than expected. The project started in 1976 but wouldn’t see the light of day until 1981. It was clear they needed something sooner, so the 8086 — a 16-bit processor clearly derived from the 8080 was born. Continue reading “How The IBM PC Went 8-Bit” →

Book Teaches Gaming Math

May 17, 2022 by Al Williams 13 Comments

If we knew how much math goes into writing a video game, we might have paid more attention in math class. If you need a refresher, [Fletcher Dunn] and [Ian Parbery] have their book “3D Math Primer for Graphics and Game Development” available free online. The book was originally a paper book from 2011 with a 2002 first edition but those are out of print now. However, math is math, so regardless of the age of the book, it is worth a look. For now, the online version is a bunch of web pages, but we hear a PDF or E-reader version is forthcoming.

There’s quite a bit of discussion about vectors, matrices, linear transformations, and 3D graphics. The last part of the book covers calculus, kinematics, and parametric curves. Some of these topics will be of interest even if you don’t care about graphics but do want to learn some math with practical examples.

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