Grappling Hook Robot Swings Like Spiderman

August 28, 2021 by Al Williams 3 Comments

We’ll admit it is a bit of a gimmick, but [Adam Beedle’s] Spider-Bot did make us smile. The little robot can launch a “web” and use it to swing. It is hard to picture, but the video below will make it all clear. It can also use the cable to climb a wall, sort of.

The bot’s ability to fling a 3D printed hook on a tether is remarkable. Details are scarce, but it looks like the mechanism is spring-loaded with a servo motor to release it. Even trailing a bit of string behind it, the range of the hook is impressive and can support the weight of the robot when it winches itself up. There’s even a release mechanism that reminds us more of Batman than Spiderman.

If we were going full autonomous, we’d consider a vision system. On the other hand, you could probably tell a lot by the tension on the cable and some way to measure the angle of it coming out of the robot. If you come up with a practical use for any of this, we’d love to see it.

We’ve seen robots that fly, jump, and can climb walls before. We don’t remember one that swings like Tarzan.

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EBike Conversion On A Budget Uses Skateboard Motor

August 28, 2021 by Mike Szczys 30 Comments

[Dave Schneider] has been chasing an electric-bike build for more than 10 years now. When he first started looking into it back in 2009, the cost was prohibitive. But think of how far we’ve come with the availability of motors, electronic speed controllers, and of course battery technology. When revisiting the project this year, he was able to convert a traditional bicycle to electric-drive for around $200.

Outrunner motor drives rear wheel via friction

Electric skateboards paved the way for this hack, as it was an outrunner motor that he chose to use as a friction drive for the rear wheel. The mounting brackets he fabricated clamp onto the chain stay tubes and press the body of the motor against the tire.

The speed of the motor is controlled by a rocker switch on the handlebars, but it’s the sensors in the brake levers that are the neat part. Magnets added to each brake lever are monitored by hall-effect sensors so that the throttle cuts whenever it senses the rider squeezing the front brake (effectively free-wheeling the bike), while the rear brake triggers a regenerative braking function he’s built into the system!

Sure you can buy these bikes, you can even buy conversion kits, but it’s pretty hard to beat the $88 [Dave] spent on the motor when the cost of purpose-built motors is usually several times this figure. The rest is fairly straight-forward, and besides ordering batteries and an electronic speed controller, you likely have the bits you need just waiting for you in your parts bin.

Simple Fan Controller Helps Apple II To Beat The Heat

August 27, 2021 by Chris Wilkinson 11 Comments

In its day, the Apple II computer didn’t typically require active cooling. However, the increasing scarcity of replacement hardware convinced [Joshua Coleman] to come up with a more robust active cooling solution for his Apple II+, increasing the likelihood that it will keep on crunching numbers for decades to come.

Joshua mentions that he recorded temperatures inside his Apple II+ peaking at 110 Fahrenheit (over 43 Celsius). This isn’t totally unexpected for a fully-loaded Apple II system, and components were built to handle this – the original datasheet for the 6500 microprocessor family reveals that the CPU can handle temperatures as high as 158 Fahrenheit (70 Celsius). Unfortunately, we’re not dealing with brand new components anymore. Decades-old microprocessors don’t necessarily have the same thermal tolerance as they once did. All components will eventually wear out, and heat can certainly accelerate the aging process.

In the interests of maintaining his system, Joshua cobbled together an Arduino-based cooling system for his Apple II+. A temperature/humidity sensor continuously monitors the heat situation inside the case – when things get too toasty, a 12V fan powers up to draw fresh air over the logic board and expansion cards. A simple cooling curve reduces wear on the fan motor and relay.

This is hardly the first active cooling system for the Apple II line – in the 1980s, Kensington produced a popular (if not stupendously ugly) ‘System Saver’ accessory, an external bolt-on fan that kept things running cool. These were often deployed in schools and by power users looking for added reliability when maxing out the Apple II expansion slots, a configuration that could increase temperatures due to the extra power requirements and reduced airflow.

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Cable Modem Turned Spectrum Analyzer

August 27, 2021 by Bryan Cockfield 19 Comments

Hopefully by now most of us know better than to rent a modem from an internet service provider. Buying your own and using it is almost always an easy way to save some money, but even then these pieces of equipment won’t last forever. If you’re sitting on an older cable modem and thinking about tossing it in the garbage, there might be a way to repurpose it before it goes to the great workbench in the sky. [kc9umr] has a way of turning these devices into capable spectrum analyzers.

The spectrum analyzer feature is a crucial component of cable modems to help take advantage of the wide piece of spectrum that is available to them on the cable lines. With some of them it’s possible to access this feature directly by pointing a browser at it, but apparently some of them have a patch from the cable companies to limit access. By finding one that hasn’t had this patch applied it’s possible to access the spectrum analyzer, and once [kc9umr] attached some adapters and an antenna to his cable modem he was able to demonstrate it to great effect.

While it’s somewhat down to luck as to whether or not any given modem will grant access to this feature, for the ones that do it seems like a powerful and cheap tool. It’s agnostic to platform, so any computer on the network can access it easily, and compared to an RTL-SDR it has a wider range. There are some limitations, but for the price it can’t be beat which will cost under $50 in parts unless you happen to need two inputs like this analyzer .

Thanks to [Ezra] for the tip!

video of someone pushing the button to generate new art

AI Generating Paintings Off To A Flying Art

August 27, 2021 by Matthew Carlson 14 Comments

The philosophical question of “What is art?” has an ethereal, transient quality to it. A definition seems to slip away as you get close to an answer. Embracing that quality, [Max Fischer] has created an AI-powered painting that paints a new piece of art at the push of a button. When the button below the screen is pushed, a new image is generated and the old one is forever lost, which in a way, makes the frame a piece of art itself.

The really makes this project stand is the sheer quality of documentation on the GitHub repo. The instructions are incredibly detailed. Everything from setting up the Jetson to building the control box out of half-inch MDF (12mm for the sane part of the world) is laid out with copious pictures. Despite the ease of generating images ahead of time, [Max] took the ~~hard route~~ Hackaday route and did all inference locally and in real-time. To handle the processing requirements, an Nvidia Jetson Xavier NX single-board computer was used. He trained StyleGAN with high-resolution abstract art that gets generated whenever the button below the screen is pushed. To prevent screen burn-in, a PIR was added to turn the screen off when no one is around.

Here at Hackaday, we’ve seen several projects putting old laptop screens or monitors into a nice wooden case and mounting them to the wall. Since 32″ laptops are rather hard to find, [Max] opted to take a different approach and instead got a 32″ Samsung Frame for relatively cheap.

For all their detail, [Max] did leave one thing out of the readme: the AI that generates the art. [Max] hints that he wants others to create their picture frames, but with their own art generation. So what are you waiting for? Go make some art.

Custom Soldering Fume Fan Doesn’t Skimp On Features

August 27, 2021 by Tom Nardi 8 Comments

Prolific maker [sjm4306] tells us the first iteration of his soldering fan was little more than some cardboard, electrical tape, and a hacked up USB cable. But as we all know, these little projects have a way of evolving over time. Fast forward to today, and his custom fan is a well-polished piece of kit that anyone with a soldering iron would be proud to have on their workbench.

Cardboard has given way to a 3D printed enclosure that holds the fan, electronics, a pair of 18650 cells, and a easily replaceable filter. Between the marbled filament, debossed logo, properly countersunk screw holes, and rounded corners, it’s really hard to overstate how good this case looks. We’ve shamefully produced enough boxy 3D printed enclosures to know that adding all those little details takes time, but the end result really speaks for itself.

Fan internals, with a look at the custom PCB.

The user interface running on the OLED is also an exceptionally nice touch. Sure the fan doesn’t need a graphical display, and [sjm4306] could have saved a lot of time and effort by using a turn-key speed controller, but the push-button configuration complete with graphical indications of fan speed and battery life really give the final product a highly professional feel.

In the video below, [sjm4306] reveals that while the finished product might look great, there were a few bumps in the road. Issues with clearance inside the case made him rethink how things would be wired and mounted, leading to a far more cramped arrangement than he’d anticipated. Part of the problem was that he designed the case first and tried to integrate the electronics later, rather than the other way around; a common pitfall you’d be wise to watch out for.

It’s been proven that, without some external input, solder smoke is going to go right in your face. Whether or not you need to do something this complex is naturally up for debate, but if you want to keep all that nasty stuff out of your lungs, you’d do well to outfit your workbench with some kind of fan.

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image of two floor lamps, one cool and one hot,

Customized Work-From-Home Lighting

August 27, 2021 by Chris Lott 7 Comments

[Jon] wants his home office lighting to mimic the light outside, at least from a color perspective. To that end, he has embarked on a design which monitors both the outdoor light and at his work station, and accordingly drives a pair of LED lamps of different colors. One lamp is rated at above 5000 K and provides “cool” lighting, , and the other is rated at less than 3000 K for “warm” lighting.

Commercial solutions do exist, but they are proprietary and do this within a single bulb and seem difficult to control in an orchestrated manner throughout the house. [Jon] plans for his approach to be scalable, eventually consisting of a variety of lighted areas of the house from a single microcontroller.

One of the design goals for this project is to create something that could disappear into the room, rather than the science fair aesthetic of my prior project.

One commenter on his project’s site asked why [Jon] is doing this, that is, what is the value of controlling the color of your indoor lighting? While [Jon] doesn’t have a specific goal in mind at the moment, he notes that these techniques could potentially be helpful for enhancing productivity, managing circadian rhythms, and as light therapy for seasonal depression.

We covered [Jon]’s science-fair-like project that in this writeup from last year. If the topic interests you, check out the white papers he links on his project page for further reading.