Axial Flux Motors For Electric Vehicles

October 10, 2021 by Al Williams 37 Comments

In the everything old is new again folder, [Lesics] has a good overview of axial flux motors. These are promising for electric vehicles, especially aircraft, since the motors should have high torque to weight ratio. The reason this is actually something old is that the early generators built by Faraday were actually of the axial flux type. Soon, though, radial flux generators and motors became the norm.

The simple explanation is that in a radial system, the magnetic flux lines are perpendicular to the axis of rotation. In the axial system, the flux lines are parallel to the axis of rotation. There’s more to it than just that of course, and the video below has nice animations showing how it all works.

While these are not very common, they do exist even today. The Lynch motor, for example, is a type of axial flux motor that dates back to 1979. Usually, the impetus for using an axial flux motor is the ease of construction, but with the right design, they can be quite efficient (up to 96% according to the video).

We’ve seen plenty of PCB motors and most of those are axial in design. Not all of them, though.

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Dial A For Arduino

October 9, 2021 by Al Williams 19 Comments

A lot of phrases surrounding phones don’t make sense anymore. With a modern cellphone, you don’t really “hang up” and there’s certainly no “dial” to be had. However, with [jakeofalltrades’] project, you can read an old-fashioned phone dial using an Arduino.

The idea behind a phone dial is actually pretty simple. When you pull the dial back to the stop using one of the numbered holes and release it, it causes a switch to open and close the same number of times as the hole you selected. That is, if you pull back the 5 hole, you should get 5 switch closures. The duration of each switch event and the time between switch events is a function of the speed the dial moves because of its internal spring. The zero hole actually produces ten pulses.

There are standards for how precise the timing has to be, but — honestly — it’s pretty loose since these were not made to be read by precise microcontroller timers. In the United States, for example, the dial was supposed to produce between 9.5 and 10.5 pulses per second, but the equipment on the other end would tolerate anything from 8 to 11.

Even if you don’t want a rotary dial in your next project, the code has some good examples of using ATmega328 timers that you might find useful in another context. However, a dial would add a nice retro touch to any numeric input you might happen to need.

If you need project inspiration, how about a volume control? Or, why not a numeric keypad?

When Benchies Fly

October 9, 2021 by Al Williams 5 Comments

Most of us have printed a few benchies to test our 3D printers. The intrepid little boat has a variety of features that tax different parts of the printing process. However, the guys at [FliteTest] had a different idea. They set out in a competition to build a giant flying benchie. They aren’t quite done, but they did make some interesting progress, as you can see in the video below.

In all fairness, the benchies are not, themselves, 3D printed. Foamboard, however, is a bit more practical. Inevitably, you can’t help but think of a flying boat when you see the results.

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Python Provides Classic Basic

October 8, 2021 by Al Williams 22 Comments

Back in the late 1970s and early 1980s when you turned on a PC, more often than not, you’d get a Basic prompt. Most people would then load a game from a tape, but if you were inclined to program you could just start writing. [Richpl] wanted that same experience and thus PyBasic was born. Along with some other Github contributors, the system has grown quite a bit and would be a good start at porting classic games or creating a replica vintage computer.

The interpreter lacks specialized hardware-specific features such as sound and graphics, of course, but then again, you could add them. It does have file I/O and also includes some interesting features like an analog of C’s ternary operator.

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Halloween Build: Exquisite Ray Gun Has Sound Effects

October 7, 2021 by Al Williams 8 Comments

When we first saw [lonesoulsurfer’s] ray gun, we thought it looked oddly familiar. Sure, it looks like a vintage ray gun you might see in a dozen 1950-era movies or TV shows. But still, there was something oddly familiar about it. Turns out, the core piece of it is an old-fashioned timing light used when doing a car tune-up.

This is no unobtrusive Star Trek phaser. It looks substantial and has a cool sound generator that not only gives it something to do but also sports cool control knobs out the top of the gun. The design files for the sound circuit are in a Google drive folder if you want to recreate the build.

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Linux Fu: Globs Vs Regexp

October 7, 2021 by Al Williams 17 Comments

I once asked a software developer at work how many times we called fork() in our code. I’ll admit, it was a very large project, but I expected the answer to be — at most — two digits. The developer came back and read off some number from a piece of paper that was in the millions. I told them there was no way we had millions of calls to fork() and, of course, we didn’t. The problem was the developer wasn’t clear on the difference between a regular expression and a glob.

Tools like grep use regular expressions to create search patterns. I might write [Hh]ack ?a ?[Dd]ay as a regular expression to match things like “HackaDay” and “Hack a day” and, even, “Hackaday” using a tool like grep, awk, or many programming languages.

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World’s Cheapest And Possibly Worst IR Camera

October 7, 2021 by Al Williams 16 Comments

Don’t blame us for the title. [CCrome] admits it may well be the cheapest and worst IR camera available. The concept is surprisingly simple. Mount a cheap Harbor Freight non-contact thermometer on a 3D printer carriage and use it to scan the target. The design files are available on GitHub.

There is, of course, an Arduino to grab the data and send it to the PC. Some Python code takes care of converting it into an image.

Perhaps you don’t need a camera, but having a way to communicate with an $11 IR temperature sensor might come in handy someday. You do have to mash the measurement button down, so [CCrome] used the 3D printer to make a clamp for the button that also holds the POGO pins to the PCB. We would have been tempted to solder across the switch and also solder the wires to the pad. But, then again, you need a 3D printer for the project anyway.

Don’t expect the results you would get from a real thermal sensor. If you want that, you may have to build it yourself or open your wallet wide. If you need some inspiration for a use case, look at the thermal camera contest from a few years back.