Mysterious Files PH

The weather is warming up, and for many of us that means more time spent working out in the yard. You probably won’t find any new life or new civilizations out there, but if you’ve spent the last few months indoors on your computer, the garden may as well be a strange new world. In that case, you’d do well to equip the members of your landing party with this Star Trek: The Original Series hose sprayer designed by [Curt Turner].

If you’re wondering how [Curt] managed to 3D print a functional hose sprayer, the short answer is that he didn’t. Once assembled, the printed parts cleverly attach to the top of a standard sprayer, specifically the model 56516 “Pro Flo” from Orbit. Without the design constraints that would have come from trying to make the thing actually contain pressurized water, [Curt] was free to focus on the aesthetics, and it shows.

Even with a garden variety — no pun intended — sprayer strapped to the bottom, it’s remarkable how much the “Sprayser” looks like the real thing. Well, not real, but you know what we mean.

[Curt] has also done an excellent job documenting this project for others that want to imagine they’re fighting off Romulans in their backyard. He’s got assembly diagrams that break down which color each of the principle components is to be printed in, as well as a build video that we’ve embedded below.

We’ve seen a fair number of Star Trek props built over the years, some of which have packed in considerably more functionality than anything they would have had back on the set. These days you can even by an officially licensed tricorder that can actually do some of the things the fictional versions were capable of.

No, we’re not talking about cultural appropriation of Japan’s most famous form of short poem–this is the other Haiku, the open-source descendant of BeOS, which now has a fully-native meshcore chat client called Sestriere, thanks to the efforts of one [Atomozero]. Of course you’ll need a LoRa radio to act as a modem, but anything that speaks USB serial– which is any of the ESP32-based offerings on the market–should work.

This is interesting in that we don’t see many desktop applications leveraging LoRa networks– meshtastic or meshcore– so for one to appear for the relatively-obscure BeOS derivative is just neat. It’s also a nice peice of work: the chat window is full featured, organizing your contacts, and communicating not just with text but emojis and reaction GIFs. GIFs seem a bit extravagant for LoRa bandwith, but apparently it works. There are also Codec2-based voice messages, another thing that we didn’t expect to see over LoRa, since most ‘chat’ projects restrict themselves to text messaging.

The software will also map all the nodes with which you are in contact, both diagrammatically and geographically, overlaid on OpenStreetMap tiles. The network map conveniently colour-codes your contacts by the link quality, but what’s even more interesting is the WireShark-inspired packet sniffer built into the software to let you keep a really close eye on traffic on the mesh network.

Neither Haiku or MeshCore are to everyone’s tastes, but as an OS it is a worthy daily driver, even if you have to jump through some hoops to install it if you have a UEFI-only system.

If you need more range, try a Yagi.

As straightforward as the concept of taking battery packs out of an old electric or hybrid car and reusing them for home power storage sounds, this thought process skips a few essential steps. As argued by [Ed] in a recent video based on his own experiences with high-voltage Nissan Leaf batteries in a home PV system, the main problem is that you’re taking a battery out of a larger system including a lot of the management hardware and software.

The referenced Battery Emulator project is an open source effort to create a suitable interface between these EV batteries, with the mentioned Nissan Leaf being just one example in the project Wiki, with the connection scheme shown in the top image. It’s also noted that the Leaf battery BMS is not designed to operate continuously, so they need to be restarted every day or so lest they become too inaccurate.

These and other things are all solid reasons why you have to be absolutely certain that you want to integrate these high-voltage battery packs into your 12 – 48V low-voltage DC system. You’re after all assuming all the responsibility of setting up a system that’s both safe and reliable, so having a good read through something like the Battery Emulator Wiki and sourcing first-hand experiences from the folk in this community would be a very wise first step.

This week Jonathan chats with Alexander Neumann about Restic, a particularly compelling backup and restore solution written in Go. Why did the world need one more backup program? And what’s Alexander’s personal take on transitioning from programmer to maintainer? Watch to find out!

• https://restic.net/
• https://github.com/restic/restic
• https://fosstodon.org/@restic

Did you know you can watch the live recording of the show right on our YouTube Channel? Have someone you’d like us to interview? Let us know, or have the guest contact us! Take a look at the schedule here.

Direct Download in DRM-free MP3.

If you’d rather read along, here’s the transcript for this week’s episode.

Theme music: “Newer Wave” Kevin MacLeod (incompetech.com)

Licensed under Creative Commons: By Attribution 4.0 License

If you look around your environment, you can probably pick off quite a few things that you’ve made, at least if you’ve been at this a while. You probably aren’t reading this from the bottom of a body of water though, which means you lack the incredible confidence of submarine builder [Hank Pronk]. Not only is he building himself a capable-looking diesel-electric submarine over on YouTube, he’s even DIYing CO2 scrubbers for it! Yeah, that’s a man who believes in himself.

Luckily [Hank] is not anywhere near the Caribbean, so needn’t worry about being misidentified as a narco-sub, but he still has to be concerned about his oxygen supply when tooling around beneath the local lakes. Perhaps more important than the oxygen supply in a sub is the build up of CO2. It doesn’t matter how many oxygen tanks you bring down with you if you can’t scrub CO2 out of the air to make room for it. Just like the Apollo missions, he’s using a chemical adsorbent to take carbon dioxide out of the air — and just like Apollo 13, he’s switching from square to round.

Or, rather, from a rather rectangular commercial model to a DIY little round unit. That’s because he doesn’t need the big scrubber in this sub: being diesel-powered, he expects to spend a lot of time at snorkel depth, where both the pilot and the engines can get clean air through the tube. Dives are expected to be short, and in that use case, too big of a CO2 scrubber is really a waste. If for some reason he gets stuck on the bottom, well, the lake isn’t that deep. He can swim to surface, and has a detailed bailout plan. If he wants to stay under overnight to avoid bailing at night, he’s carrying enough extra adsorbent for that.

There’s a reason almost every submarine we’ve featured on this site over the years is an ROV. It’s not that a homemade submarine is automatically a death trap, but you sure do have to be confident in your design.

When it comes to robots, few are as iconic as Robby. [Ogrinz Labs] has wanted to build one and even examined a real one up for auction to get high-res photos of it. He also combined his designs with some other open-source designs, and it looks good. He’s released his design as a Creative Commons-licensed set of STL files that you, in theory, could print. There are more details and instructions in the video below.

If you are looking for something quick to print for the weekend, this isn’t it. As you might expect, this is a lot to print. The creator admits, too, that it isn’t totally accurate. It has bigger feet, for example, so his feet can fit inside. There are a few other modifications made for different reasons, but only a hard-core Robby enthusiast would notice any of them.

In theory, you can wear the robot as a costume, but at the current height, it doesn’t look like that will work for the creator. Also, the joints that would make things rotate are still forward work, but he’s promised to provide updates.

Robby started out on Forbidden Planet and went on to appear in many other movies and TV shows. Much of the original body was vacuum-formed plastic (an early form of ABS known as Royalite).

Thanks to modern slicers, you can easily print the parts on your printer for later assembly, and the video shows you how. You can select what connectors are used, and while we like the dovetail mode for most of what we do, Robby’s clean surfaces need dowel connectors. We would be really excited to see someone take these files and make a working robot based on the design.

We’ve been watching this project for a while. If you are sorry you missed the auction of the original, you aren’t alone. But we couldn’t have afforded the $5,375,000 price tag anyway.

For those of us old enough to remember the harrowing days of the early 2020s, alongside another major kerfuffle there was a complete breakdown in global supply chains that led to the 2020-2023 global chip shortage. Unsurprisingly, this pushed many hardware manufacturers into less orthodox approaches, massive BOM changes, and hurried redesigns. One of the results of this era found its way into the hands of the bloke over at the [Playduino] YouTube channel, who was mystified to find two bodge wires in his fancy Saleae logic analyzer.

The reason for popping open the LA was crosstalk between two channels, which was bad enough that it made the unit quite unusable for the intended task. After seeing the cut traces and bodge wires he initially assumed that since he bought it used that the previous owner had modified it, but said person denied having opened it since purchasing it from an official retailer.

This was when he emailed Saleae support to see whether they knew anything. Initially they denied knowing anything about such a modification, but then the CTO emailed back with a long and very detailed confession. As explained in the video, during the aforementioned chip crisis Saleae was forced to rapidly redesign their LAs to use whatever FPGAs and other parts they could still get their hands on.

An initial prototype unit passed their internal tests, so they had a first batch manufactured using PCBs from a different supplier. Despite sending the same Gerber files, the resulting PCBs had ground fill issues that necessitated the observed rework, but due to insufficient testing for crosstalk a total of 406 units made it into the wild.

Sadly he had to return the defective unit for a replacement, making it somewhat hard to let go of such a piece of history. That said, if you want to know whether you’re also one of the lucky remaining 405 LA owners, the CTO provided the affected serial number range: 00200026245 to 00200026675 are affected.