Bend Your Vase Mode Prints By Hacking The GCode

February 22, 2022 by 3 Comments

[Stefan] from CNCKitchen wanted to make some bendy tubes for a window-mountable ball run, and rather than coming up with some bent tube models, it seemed there might be a different way to achieve the desired outcome. Starting with a simple tube model designed to be quickly printed in vase mode, he wrote a Python script which read in the G-Code, and modified it allow it to be bent along a spline path.

Vase mode works by slowly ramping up the Z-axis as the extruder follows the object outline, but the slicing process is still essentially the same, with the object sliced in a plane parallel to the bed. Whilst this non-planar method moves the Z-axis in sync with the horizontal motion (although currently limited to only one plane of distortion, which simplifies the maths a bit) it is we guess still technically a planar solution, but just an inclined plane. But we digress, non-planar in this context merely means not parallel to the bed, and we’ll roll with that.

[Stefan] explains that there are quite a few difficulties with this approach. The first issue is that on the inside of the bend, the material flow rate needed to be scaled back to compensate. But the main problem stems from the design of the extruder itself. Intended for operating parallel to the bed, there are often a few structures in the way of operating at an angle, such as fan mounts, and the hotend itself. By selecting an appropriate machine and tweaking it a bit, [Stefan] managed to get it to work at angles up to 30 degrees off the horizontal plane. One annoyance was that the stock nozzle shape of his E3D Volcano hotend didn’t lend itself to operating at such an inclination, so he needed to mount an older V6-style tip with an adapter. After a lot of tuning and fails, it did work and the final goal was achieved! If you want to try this for yourselves, the code for this can be found on the project GitHub.

If you want to learn more about non-planar printing, we’ve covered the process of non-planar slicing a while back, and if you think your 2.5D printer doesn’t quite have the range for really funky print paths, then you may want to look into a robot arm based printer instead.

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AI Maybe Revives Dead Languages

February 22, 2022 by 45 Comments

While Star Trek’s transporter is hard to imagine — perfect matter movement across vast distances with no equipment on one end — it may not be the most far-fetched piece of tech on the Enterprise. While there are several contenders, I strongly suspect the universal translator is the most unlikely MacGuffin. After all, how would you decipher a totally unknown language in real-time? Of course, no one wants to watch 30 episodes of TV about how we finally figured out what Klingons call clouds, so pretty much every science fiction movie has some hand-waving explanation for speaking the viewer’s language. Farscape had microbes, some aliens have telepathy that works with alien brains of any kind, and still others study English from afar for decades off camera. Babelfish anyone?

I was thinking about this because of an article I read by [Alizeh Kohari] about [Jiaming Luo’s] work using AI to decode dead languages. While this might seem to be similar to Spock’s translator, it really isn’t. Human languages change over time and distance. You only have to watch the BBC or read something written by Thomas Jefferson to see that. But there is still a lot in common, at least within certain domains.

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A doorblell made from a stepper motor and a hard drive

Minimalistic Doorbell Doesn’t Need An Internet Connection – Or Even A Power Supply

February 22, 2022 by 57 Comments

Doorbells are among those everyday objects that started out simple but picked up an immense amount of complexity over the years. What began as a mechanism to bang two pieces of metal together evolved into all kinds of wired and wireless electric bells, finally culminating in today’s smart doorbells that beam a live video feed to their owners even if they’re half a world away.

But sometimes, less is more. [Low tech obsession] built a doorbell out of spare components that doesn’t require Internet connectivity or even a power supply. But it’s not a purely mechanical device either: the visitor turns a knob mounted on a stepper motor, generating pulses of alternating current. These pulses are then fed into the voice coil of an old hard drive, causing its arm to vibrate and strike a bell, mounted where the platters used to be.

Besides being a great piece of minimalistic design, the doorbell is also a neat demonstration of Faraday’s law of induction. The stepper motor is apparently robust enough to withstand vandalism, although we can imagine that the doorbell’s odd shape might confuse some well-meaning visitors too. If you’re into unusual doorbells, you might want to check out this one made from an old wall phone, as well as this electromechanical contraption.

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Big Chemistry: From Gasoline To Wintergreen

February 22, 2022 by 18 Comments

Most of us probably have some vivid memories of high school or college chemistry lab, where the principles of the science were demonstrated, and where we all got at least a little practice in experimental methods. Measuring, diluting, precipitating, titrating, all generally conducted under safe conditions using stuff that wasn’t likely to blow up or burn.

But dropwise additions and reaction volumes measured in milliliters are not the stuff upon which to build a global economy that feeds, clothes, and provides for eight billion people. For chemistry to go beyond the lab, it needs to be scaled up, often to a point that’s hard to conceptualize. Big chemistry and big engineering go hand in hand, delivering processes that transform the simplest, most abundant substances into the things that, for better or worse, make life possible.

To get a better idea of how big chemistry does that, we’re going to take a look at one simple molecule that we’ve probably all used at one time or another: the common artificial flavoring wintergreen. It’s an innocuous ingredient in a wide range of foods and medicines, but the infrastructure required to make it and all its precursors is a snapshot of just how important big chemistry really is.

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No Privacy: Cloning The AirTag

February 22, 2022 by 55 Comments

You’ve probably heard of the infamous rule 34, but we’d like to propose a new rule — call it rule 35: Anything that can be used for nefarious purposes will be, even if you can’t think of how at the moment. Case in point: apparently there has been an uptick in people using AirTags to do bad things. People have used them to stalk people or to tag cars so they can be found later and stolen. According to [Fabian Bräunlein], Apple’s responses to this don’t consider cases where clones or modified AirTags are in play. To prove the point, he built a clone that bypasses the current protection features and used it to track a willing experimental subject for 5 days with no notifications.

According to the post, Apple says that AirTags have serial numbers and beep when they have not been around their host Apple device for a certain period. [Fabian] points out that clone tags don’t have serial numbers and may also not have speakers. There is apparently a thriving market, too, for genuine tags that have been modified to remove their speakers. [Fabian’s] clone uses an ESP32 with no speaker and no serial number.

The other protection, according to Apple, is that if they note an AirTag moving with you over some period of time without the owner, you get a notification. In other words, if your iPhone sees your own tag repeatedly, that’s fine. It also doesn’t mind seeing someone else’s tags if they are near you. But if your phone sees a tag many times and the owner isn’t around, you get a notification. That way, you can help identify random tags, but you’ll know if someone is trying to track you. [Fabian] gets around that by cycling between 2,000 pre-loaded public keys so that the tracked person’s device doesn’t realize that it is seeing the same tag over and over. Even Apple’s Android app that scans for trackers is vulnerable to this strategy.

Even for folks who aren’t particularly privacy minded, it’s pretty clear a worldwide network of mass-market devices that allow almost anyone to be tracked is a problem. But what’s the solution? Even the better strategies employed by AirGuard won’t catch everything, as [Fabian] explains.

This isn’t the first time we’ve had a look at privacy concerns around AirTags. Of course, it is always possible to build a tracker. But it is hard to get the worldwide network of Bluetooth listeners that Apple has.

Super Simple Camera Slider With A Neat Twist

February 22, 2022 by 5 Comments

When you get into making videos of products or your own cool hacks, at some point you’re going to start wondering how those neat panning and rotating shots are achieved. The answer is quite often some kind of mechanical slider which sends the camera along a predefined path. Buying one can be an expensive outlay, so many people opt to build one. [Rahel zahir Ali] was no different, and designed and built a very simple slide, but with a neat twist.

This design uses a geared DC motor, taken from a car windscreen wiper. That’s a cost effective way to get your hands on a nice high-torque motor with an integral reduction gearbox. The added twist is that the camera mount is pivoted and slides on a third, central smooth rod. The ends of this guide rod can be offset at either end, allowing the camera to rotate up to thirty degrees as the slide progresses from one end to the other. With a few tweaks, the slider can be vertically mounted, to give those up-and-over shots. Super simple, low tech and not an Arduino in sight.

The CAD modelling was done with Fusion 360, with all the models downloadable with source, in case someone needs to adapt the design further. We were just expecting a pile of STLs, so seeing the full source was a nice surprise, given how many open source projects like this (especially on Thingiverse) do often seem to neglect this.

Electronics consist of a simple DC motor controller (although [Rahel] doesn’t mention a specific product, it should not be hard to source) which deals with the speed control, and a DPDT latching rocker switch handles the motor direction. A pair of microswitches are used to stop the motor at the end of its travel. Other than a 3D printer, there is nothing at all special needed to make yourself quite a useful little slider!

We’ve seen a few slider designs, since this is a common problem for content creators. Here’s a more complicated one, and another one.

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A vintage pocket calculator with extra exposed circuitry added

I2C Breathes New Life Into Casio Pocket Calculator

February 21, 2022 by 6 Comments

When is a pocket calculator more than just a calculator? [Andrew Menadue] has been pushing the limits of his 1970s Casio FX-502P by adding all sorts of modern functionality via the calculator’s expansion port.

Several older Casio calculators included an expansion port for connecting cassette tape storage and printing functionality. Data on the FX-502P could be saved on cassette tape using the well-known Kansas City standard, however this signal was produced by Casio’s FA-1 calculator cradle, not the FX-502P itself. To interact with the calculator itself would require an understanding of whatever protocol Casio designed for this particular model.

It turns out that the protocol is a little quirky compared to its contemporaries, with variable length data packets and inverted data logic, (zero volts is ‘1’ and three volts is ‘0’). Once the protocol was untangled, it was ‘simply’ a matter of connecting the calculator to the GPIO interface on the STM32, and using some software wizardry to start shooting data packets back and forth.

This hack can be used to send and receive data from an SD card (via a RAM buffer), however it’s the other expansion capabilities that really make us wonder. [Andrew] has demonstrated how easy it is to add a real-time clock or thermal printer. Using the I2C capabilities of the STM32, it’s likely that all sorts of gadgets and sensors could be coupled with this vintage calculator, and many others like it.

You can find even more details about this hack over here, including some follow up videos to the original hack. No stranger to vintage calculators, we last featured [Andrew] after he retrofitted a modern LCD display to an old Casio. It’s charming to see how these calculators are far from obsolete.

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