Solar Plane Is Like One Big Flying Solar Panel

Solar-powered plane concepts typically focus on high-efficiency glider-type designs, so as to make the best possible use of the limited power available from the sun. [rctestflight] wanted to try a different school of thought, instead building a relatively inefficient plane that nonetheless packed a huge amount of solar panels on board.

The plane consisted of a pizza-box style design, with a simple foam rectangular wing that was absolutely covered in solar panels. The plane was controlled with an off-the-shelf autopilot, and fitted with cheap, no-brand MPPT modules to handle charging the batteries. The plane faced difficulties in flight, most often with stability, which led to the autopilot getting the plane lost on one occasion. However, one flight was achieved with a full one hour and thirty minute duration, indicating the solar panels were helping to extend flight times beyond what was capable with batteries alone.

Further research on the ground showed that the cheap MPPT modules were wasting power, and there was more to be had. A better MPPT module was subbed in and showed that the panels could generate up to 5 amps under good conditions, while the plane only needed roughly 4.2 amps to fly. This would allow for indefinite flight in sunny conditions, though probably would not allow enough energy to be banked to fly 24 hours round the clock due to the lack of power at night.

We’ve followed [rctestflight]’s solar plane experiments for a while now, and can’t wait to see the next iteration. Video after the break.

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3D Printed Flip Dots

Displays have come a long way in the last few decades, but none can deliver the mesmerizing visual and audio experience of a large flip dot display. Both old panels and new panels can be expensive and difficult to source, so [Larry Builds] made his own flip dots with the help of 3D printing.

Flip dots are driven by a pair of electromagnetic posts that attract or repel a magnet embedded in the dot, and [Larry Builds] version is no different. For the electromagnets, he used M3 threaded rod with enamel wire wound around them using a drill. At first, he used a large magnet in the center of the 3D printed dot, but the magnetic field was large and strong enough to flip the surrounding dots in an array. He then changed the design to a small 4 mm diameter magnet in the edge that aligns directly with the electromagnets. This design looks very similar to those used by Breakfast for their massive installations. By modifying electromagnets and adding spacers around the magnets, he was able to reduce the operating current from 2 A to below 500 mA. [Larry Builds] also breadboarded a basic driver circuit consisting of H-bridges multiplexed to rows and columns with diodes.

We will be keeping a close eye on this project, and we look forward to seeing it evolve further. It’s definitely on our “things to build” list. We’ve embedded multiple videos after the break showing the progress thus far.

We’ve covered several interesting flip dot projects, including a water level indicator that doesn’t use any electronics and another that is crocheted. Continue reading “3D Printed Flip Dots”

3D Printed Mars Rover Smiles For The Camera

You’d be forgiven for thinking these pictures of NASA’s Perseverance Mars rover were renderings of the real deal on the Red Planet, if it wasn’t for the golf ball tucked in for scale, anyway. What you’re actually looking at is a 3D printed model made by [Alex Givens] that he brought out to the desert for a photo shoot by his friend [Josh Jalil].

[Alex] printed the parts for the model on the Ender 5 Pro, while [Josh] snapped the shots using a Canon EOS 90D. The realism of the final shots serves as a testament to how well they’ve honed their respective tools, but credit for the 3D model itself has to go to the good folks over at NASA.

The highly detailed Perseverance model came from the space agency’s extensive “3D Resources” collection, which has models for an incredible array of present and historical spacecraft. They’ve also got models for a number of interesting astronomical objects, just in case you’re in the market for a 3D printed asteroid or two.

We know, this isn’t exactly a hack in the traditional sense. But it’s a fantastic reminder of a great resource from NASA, as well as a practical demonstration of how high quality photographs can really bring a project to life.

Can You Hot-Swap Flash Chips In A Consumer Router?

Sometimes, you mess up when toying with the firmware of an embedded device and end up “bricking” what you were working on. [Chris Bellows] had done just that with a consumer router, corrupting the onboard NAND flash to the point where recovery via normal means was impossible. Armed with a working duplicate of the router, he wondered if the corrupted NAND flash could be substituted into the working router while it was running, and reflashed in place – and decided to find out.

Key to achieving the hack was finding a way to remove the existing NAND flash in the working router without crashing the system while doing so. This required careful disconnection of the chip’s power lines once the router had booted up, as well as tying the “Ready/Busy” and “Read Enable” pins to ground. With this done, the chip could carefully be removed with a hot air tool without disrupting the router’s operation. The new chip could then be soldered in place, and flashed with factory firmware via the router’s web interface. At this point, it could be powered down and the chips swapped normally back into their own respective routers, restoring both to full functionality.

It’s a neat hack, and one that shows that it’s sometimes worth taking a punt on your crazy ideas just to see what you can pull off. It also pays to know the deeper secrets of the hardware you run on your own home network.

TNDLPT Brings Tandy Sound To Any DOS Computer

The Tandy 1000, among other contemporary computers and consoles of the 1980s, used the Texas Instruments SN76489 for its sound and musical output. This venerable sound chip can now be used on virtually any DOS machine, as long as it has a parallel port – thanks to the TNDLPT adapter!

The adapter consists of the SN76489, hooked up to the parallel port so that it can be addressed by the host computer via a DOS Terminate and Stay Resident program acting as a driver. With the TSR loaded, classic DOS games can be used with the TNDLPT sound output by simply selecting the Tandy 1000 soundcard at install. It can also be used in a variety of other ways, such as with the TNDY tracker for music creation, or the SBVGM soundtrack player.

For those eager to hear the soaring 3 voices (and one noise channel!) of the SN76489 once again, this is a great way to do it, with kits available on the Serdashop site for those wishing to solder up their own. Alternatively, get a different vibe with the OPL2 instead. Video after the break.

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One Inkscape Plugin Collection To Rule Them All

Inkscape is an amazing piece of open source software, a vector graphics application that’s a million times more lightweight than comparable commercial offerings while coming in at the low, low price of free. The software also has plenty of extensions floating around on the Internet, though until now, they haven’t been organised particularly well. The MightyScape project aims to solve that, putting a bunch of Inkscape plugins into one useful release.

The current MightyScape release has a whole bunch of useful stuff inside, for tasks as varied as laser cutting, 3D printing, vinyl cutting, as well as improvements on areas where Inkscape is a bit weak out of the box – like CAD, geometry and patterning. The extensions are maintained and working, albeit with some bugs, and are intended for use with Inkscape 1.0 and above.

The aim is that by creating an overarching collection, the MightyScape project will help inspire the community to come together and actively maintain Inkscape plugins rather than allowing them to wither and die when forgotten by their original creators. That’s the benefit of open-source, after all – you can do whatever you want with the software when you have the code to do so!

Cocktail Of Chemicals Makes This Blueprint Camera Unique

When you’re looking at blueprints today, chances are pretty good that what you’re seeing is anything but blue. Most building plans, diagrams of civil engineering projects, and even design documents for consumer products never even make it to paper, let alone get rendered in old-fashioned blue-and-white like large-format prints used to produced. And we think that’s a bit of a shame.

Luckily, [Brian Haidet] longs for those days as well, so much so that he built this large-format cyanotype camera to create photographs the old-fashioned way. Naturally, this is one of those projects where expectations must be properly scaled before starting; after all, there’s a reason we don’t go around taking pictures with paper soaked in a brew of toxic chemicals. Undaunted by the chemistry, [Brian] began his journey with simple contact prints, with Sharpie-marked transparency film masking the photosensitive paper, made from potassium ferricyanide, ammonium dichromate, and ammonium iron (III) oxalate, from the UV rays of the sun. The reaction creates the deep, rich pigment Prussian Blue, contrasting nicely with the white paper once the unexposed solution is washed away.

[Brian] wanted to go beyond simple contact prints, though, and the ridiculously large camera seen in the video below is the result. It’s just a more-or-less-lightproof box with a lens on one end and a sheet of sensitized paper at the other. The effective ISO of the “film” is incredibly slow, leading to problematically long exposure times. Coupled with the distortion caused by the lens, the images are — well, let’s just say unique. They’ve got a ghostly quality for sure, and there’s a lot to be said for that Prussian Blue color.

We’ve seen cyanotype chemistry used with UV lasers before, and large-format cameras using the collodion process. And we wonder if [Brian]’s long-exposure process might be better suited to solargraphy.

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