If you go to, say, a football game, you probably don’t get to see as much of the game as close as you do when you stay home and watch on TV. But there’s something about being there that counts. That’s probably how [Sebastian Voltmer] feels. While we’ve all seen video of astronauts and cosmonauts spacewalking, [Sebastian] managed to take a snapshot of a pair of spacewalkers from his telescope.
Of course, this wasn’t your ordinary department store Christmas gift telescope. The instrument was a Celestron 11 inch EdgeHD Schmidt-Cassegrain telescope on a very expensive GM2000 HPS mount. An ASI290 planetary camera took the shot. You can see the gear and more about the photos in the video below.
We’ve seen this funky dual disk polar printer already recently, but [Heinz Loepmeier] has been busy working on it, so here’s an update. The primary focus here is nozzleboss, a blender plugin which enables the surface textures of already sliced objects to be manipulated. The idea is to read in the gcode for the object, and convert it to an internal mesh representation that blender needs in order to function. From there the desired textures can be applied to the surfaces for subsequent stages to operate upon. One trick that nozzleboss can do is to create weight maps to tweak the extrusion flow rate or print velocity value according to the pixel value at the surface — such ‘velocity painting’ can produce some very subtle surface effects on previously featureless faces. Another trick is to use the same weight maps and simply map colours to blender text blocks which are injected into the gcode at export time. These gcode blocks can be used swap tool heads or extruders, enabling blending of multiple filament colours or types in the same object.
Some nice examples of such printing manipulation can be seen on [Heinz’s] instagram page for the project. So, going back to the hardware again, the first video embedded below shows the ‘dual disk polar printer’ fitted with a crazy five-extruders-into-one-nozzle mixing hotend setup, which should be capable of full CMYK colour mixing and some. The second video below shows an interesting by-product of the wide horizontal motion range of the machine, that the whole printing area can be shifted to a nozzle at the other end of the gantry. This enables a novel way to switch extruders, by just moving the whole bed and print under the nozzle of interest! One final observation — is that of the print surface — it does look rather like they’re printing direct onto a slab of marble, which I think is the first time we’ve seen that.
Interesting printer designs are being worked on a lot these days, here’s a really nice 5-axis prusa i3 hack, and if you want to stay in the cartesian world, but your desktop machine is just too small, then you can always supersize it.
The first electronic digital watches were admired for their pioneering technology, if not their everyday practicality, when they were introduced in the 1970s. Their power-hungry LED displays lit up only when you pressed a button, and even then the numbers shown were tiny. Their cases were large and heavy, and they drained their batteries rather quickly even when not displaying the time. Still, the deep red glow of their displays gave them a certain aesthetic that’s hard to replicate with today’s technology.
When [Benjamin Sølberg] got his hands on an Elektronika-1, a first-generation digital watch designed in the Soviet Union, he set about designing a modern replacement for its internals. Where the original had several custom chips wire-bonded directly onto a substrate, the new board contains an MSP430 series microcontroller as well as an AS1115 display driver. The PCB makes contact with the watch’s pushbuttons through clever use of castellated holes.
For the display [Benjamin] went with period-correct LED modules made by HP, which keep the display’s appearance as close to the original as possible. While these draw quite a bit of current, the rest of the watch has become an order of magnitude more frugal: the stand-by time is now estimated to be about ten years, where the old design often needed new batteries within a year. [Benjamin] uses his renovated watch on a daily basis, apparently without trouble.
If you’ve got an old Soviet digital watch that you’d like to upgrade, you’ll be pleased to hear that the entire design is open source. Just like this retro watch, in fact, that uses a similar LED display. If you’re into original vintage watches, we’ve covered them in depth, too.
When you’re driving around, you might occasionally notice your indicators or windscreen wipers sync up fortuitously with the music. [Cranktown City] wanted to ensure his wipers would always match the beat, however, and set about making it so.
After disassembling the wiper motor, The original controller PCB is ripped up, used solely for its home position contacts that help determine the position of the wipers. The battered board is then drilled out to fit a rotary encoder to track the wipers throughout their full motion.
An Arduino is used to read the signal coming from the wiper stalk in order to know what mode the wipers should be in, and uses a motor controller to drive the wipers thusly. It also reads the encoder and home position contacts to track the wiper movement, and uses a proportional controller to control the wiper position. An MSGEQ7 spectrum analyzer is used to track the bass of the music to determine the beat to sync up to.
YouTuber [Linguoer] has a knack, and it’s one that we don’t often see on the pages of Hackaday: rewinding and rebuilding dilapidated motors and generators. In the video below, you’ll see [Lin] take a hydroelectric turbine and generator that looks like it’s been sitting at the bottom of a lake, and turn it into a working unit, all while wearing her trademark blue and yellow denim jumpsuit.
Where as most makers would have used a MIG or TIG welder, [Linguoer] uses a simple (probably A/C) stick welder. Generator windings are calculated and wound by hand, and the carcass of what used to be the generator is sandblasted out in the open. Missing parts are fabricated from scratch using nothing more than an angle grinder. “Simple” is the order of the day.
[Linguoer] often refers to herself as “Village Girl”. Whatever specialty tools she uses, they are elementary. And whatever methods she uses, they are manual. You will get the idea very quickly that [Linguoer] isn’t just a person with a skill, but a person with a passion for getting things done no matter the circumstances. [Linguoer] is a hacker if there ever was one!
We are always impressed with something so simple can actually be so complex. For example, what would you think goes into an analog computer? Of course, a “real” analog computer has opamps that can do logarithms, square roots, multiply, and divide. But would it surprise you that you can make an analog device like a slide rule using a Wheatstone bridge — essentially two voltage dividers. You don’t even need any active devices at all. It is an old idea and one that used to show up in electronic magazines now and again. I’ll show you how they work and simulate the device so you don’t have to build it unless you just want to.
A voltage divider is one of the easiest circuits in the world to analyze. Consider two resistors Ra and Rb in series. Voltage comes in at the top of Ra and the bottom of Rb is grounded. The node connecting Ra and Rb — let’s call it Z — is what we’ll consider the output.
Let’s say we have a 10 V battery feeding A and a perfect voltmeter that doesn’t load the circuit connected to Z. By Kirchoff’s current law we know the current through Ra and Rb must be the same. After all, there’s nowhere else for it to go. We also know the voltage drop across Ra plus the voltage drop across Rb must equal to 10 V. Kirchoff, conservation of energy, whatever you want to call it. Let’s call these quantities I, Va, and Vb. Continue reading “Circuit VR: The Wheatstone Bridge Analog Computer”→
As a quantified-self experiment, [Ayan] has tracked several daily habits and moods for a couple of years and discovered some insights. Too much coffee is followed by anxiety while listening to music leads to feelings of motivation and happiness. There was a strong correlation in the data, but [Ayan] wondered if external factors like the weather and air quality also played a role.
To find out, [Ayan] extended the custom dashboard built in Notion.so with weather data and some local sensors. Working at Balena.io (yes, the makers of the ubiquitous Raspberry Pi SD card flashing tool, Etcher), [Ayan] turned to balenaCloud to translate the data from (you guessed it) a Raspberry Pi into the dashboard via Notion’s API beta. We think Notion holds a lot of promise for all sorts of web-based dashboards as a research notebook and organizational tool. Who knows where the API will lead any interested readers?
Check out the full tutorial where [Ayan] walks you through the hardware used and each step to connect the APIs that bring it all together. [Ayan] plans to add a coffee-maker integration to automate that data entry and would welcome help getting a manual trigger set up for the data integrations.