Slicer Settings For “Indestructible” Battle-Bot Worthy PLA Parts

If you follow [Maker’s Muse] on YouTube, you know he’s as passionate about robot fights these days as he is about the tools he uses to make the robots. Luckily for us, he’s still got fame as a 3D printing YouTuber, as this has given him the platform to share his trade secrets for strong, robot-combat-worthy prints.

He fights robots in a ‘plastic ant-weight’ division, which restricts not only the weight of the robot but also the materials used. Not only must they be primarily plastic, but only certain plastics are allowed: PLA is in, but engineering filaments, Nylon, and TPU are out. Since necessity is the mother of invention, this has led to strong evolutionary pressure to figure out how to print the most impact-resilient PLA parts for armor and spinners.

He’s using the latest OrcaSlicer and shares the profile as a pay-what-you-want 3MF file. It’s all about solidity: a solid part with solidly fused walls and solidly linked layers. It makes sense: if you’re going to be hammering on or with these parts, you don’t want any internal voids that could either collapse or pull open.

The infill density is obviously 100%, and you’ll want a concentric pattern — this makes it look like you’re just printing walls, but it allows you to use another trick. To make sure those walls don’t all align, creating a potential weakness, OrcaSlicer’s “alternate extra wall” will put one extra wall every second layer. The extra wall causes the infill pattern to stagger and lock together.

Also helping lock it together, he’s playing with extrusion widths, with the suggested rule-of-thumb being the line width on the walls be one-half that of the internal fill — and as wide as possible. In his case, with a 0.4 mm nozzle, that means 0.4 mm wide walls and 0.8 mm for the infill. OrcaSlicer 2.3.2 also lets you play with specific flow ratios, allowing you to overextrude only the internals for strength, without overextruding on the walls and potentially ruining dimensional accuracy. He also irons all top surfaces, but admits that that’s mostly about aesthetics. The iron may make those layers a little bit stronger, though, so why not?

Would brick layers make these parts even stronger? That’s very likely; [Maker’s Muse] mentions them in the video but does not use them because they’re not implemented in-slicer, and he wants something accessible to all. On the other hand, this post-processing script seems accessible enough for our crowd.

This video/profile is exclusively about fully-solid parts. When you want strong parts that aren’t fully solid, it looks like the answer is walls.

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Your Own Tool Changer

All the cool new 3D printers have tool-changing heads. Instead of multiplexing filament through one hot end, you simply park one hot end and pick up another. Or pick up a different tool, depending on what you need. There are many advantages to a system like that, but one disadvantage: cost. [Ultimate Tool Changer] has been working on a design for what he calls a simple, cheap changer, and it appears to be working well, as you can see in the video below.

This is one of those things that seems easy until you try to do it. He talks about a lot of the failures and dead ends along the way.

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This Week In Security: Flatpak Fixes, Android Malware, And SCADA Was IOT Before IOT Was Cool

Rowhammer attacks have been around since 2014, and mitigations are in place in most modern systems, but the team at gddr6.fail has found ways to apply the attack to current-generation GPUs.

Rowhammer attacks attach the electrical characteristics of RAM, using manipulation of the contents of RAM to cause changes in the contents of adjacent memory cells. Bit values are just voltage levels, after all, and if a little charge leaks across from one row to the next, you can potentially pull a bit high by writing repeatedly to its physical neighbors.

The attack was used to allow privilege escalation by manipulating the RAM defining the user data, and later, to allow reading and manipulation of any page in ram by modifying the system page table that maps memory and memory permissions. By 2015 researchers refined the attack to run in pure JavaScript against browsers, and in 2016 mobile devices were shown to be vulnerable. Mitigations have been put in place in physical memory design, CPU design, and in software. However, new attack vectors are still discovered regularly, with DDR4 and DDR5 RAM as well as AMD and RISC-V CPUs being vulnerable.

The GDDR6-Fail attack targets the video ram of modern graphics cards, and is able to trigger similar vulnerabilities in the graphics card itself, culminating in accessing and changing the memory of the PC via the PCI bus and bypassing protections.

For users who fear they are at risk — most likely larger AI customers or shared hosting environments where the code running on the GPU may belong to untrusted users — enabling error correcting (ECC) mode in the GPU reduces the amount of available RAM, but adds protection by performing checksums on the memory to detect corruption or bit flipping. For the average home user, your mileage may vary – there’s certainly easier ways to execute arbitrary code on your PC – like whatever application is running graphics in the first place!

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A mechanical keyboard, transformed to look like a retro laptop with an ipad for a screen

Modular Mechanical Keyboard Transformed Into A Compact Workstation

3D printing is a staple of the hacker community. From decorative items to rugged functional parts, almost anything you can think of, can be printed. [anurag.id] shows us some classic 3D printing hacks by converting his keyboard into a compact workstation.

Like any hacker project, the initial idea is small: he decides the knob on his mechanical keyboard is boring, so he designs some alternatives. First, one “retro style” knob. Then, like any good project, the scope creep begins. He makes another knob, and another… by the end he has 6 different designs! But don’t worry, the scope can get even bigger. He decides his ipad needs a good stand on his desk–and what better place to put it than on the keyboard? Now it’s starting to look like a real little workstation. Finally, as a finishing touch, he adds some magnetically-attached wrist rests for a compact, ergonomic workstation.

Video after the break.
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3D Print Becomes Cast Iron Wrench Via Microwave

Consumer-grade 3D printing is good for prototyping and making relatively soft plastic stuff. If you wanna make tough things, though, it’s really hard to beat the strength of metal. [Shake the Future] has produced a guide on using 3D printing in a process to produce solid parts out of actual cast iron.

The concept is simple. [Shake the Future] uses silicon carbide crucibles, which can heat up by absorbing microwave energy. Put one in an insulated container, dump some metal in, and throw it in a microwave, and soon enough you have a pot of molten metal you can use to cast stuff.

Let’s say you want to make an adjustable wrench, which is how [Shake the Future] demonstrates this technique. The first step is to print the wrench parts in plastic, such as PLA. These parts are then packed into fine sand to create casting molds. The PLA is burned out of the mold, leaving a negative imprint of the geometry. Molten cast iron can then be poured into the mold to create the part in solid metal.

It’s a messy technique that requires a lot of manual labor, but it does work quite well. There are some tricks to learn, though, particularly when it comes to successfully casting parts with holes or fine geometric features.

And before you think that you’re going to put the hardware store out of business, it should also be noted that it failed on first encounter with a real-world nut. The thinnest part by the screw just wasn’t strong enough.

Still, it’s a great demo, and if you’ve ever wanted to make a bespoke cast iron part of your own, this work may be very relevant to you. Alternatively, consider learning about DIY aluminium castingjust consider the pitfalls involved.

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How I 3D Printed My Own Lego-Compatible Train Bridges

Lego train sets have been available for decades, now. The Danish manufacturer long ago realized the magic of combining its building block sets with motors and plastic rails to create real working railways for children and adults to enjoy. Over the years, Lego has innovated through several generations of trains, from classic metal-rail systems to the more modern IR and later Bluetooth-controlled versions. The only thing largely missing over all that time, though…? A bridge!

Yes, Lego has largely neglected to build any bridges for its mainstream train lineup. There are aftermarket solutions, and innovative hacks invented by the community, all with their own limitations and drawbacks. This glaring oversight, though, seemed like a perfect opportunity to me. It was time to fire up the 3D printer and churn out a fully-realized Lego rail bridge of my very own.

Bridges Are Hard

I’ve experimented with building Lego rail bridges before, using standard track and household objects like cardboard, books, and beer. Unfortunately, it can be very difficult to support the track evenly at the joints which occur every 150mm, and derailments are common. Credit: author

There’s actually a good reason Lego bridges aren’t a big thing in the company’s own product lineup, beyond a few obscure historical parts. This is probably because they aren’t very practical. Lego locomotives are not particularly strong haulers, nor do they have excellent grip on the rails, and this makes them very poor at climbing even mild grades. Any official Lego bridge would have to be very long with a shallow slope just to allow a train to climb high enough to clear a locomotive on a track below. This would end up being an expensive set that would probably prove unpopular with the casual Lego train builder, even if the diehard enthusiasts loved it. 

There are third-party options available out there. However, most rely on standard Lego track pieces and merely combine them with supports that hold them up at height. This can work in some cases, but it can be very difficult to do cool things like passing a Lego train under a bridge, for example. It can be hard to gain enough height, and the short length of Lego track pieces makes it hard to squeeze a locomotive between supports. Continue reading “How I 3D Printed My Own Lego-Compatible Train Bridges”

A Smart Printer Enclosure For The Open Source World

3D printing has had its time to spread its wings into the everyday home, yet many of those homes lack the proper ventilation to prevent the toxic VOCs from escaping. Because of this, [Clura] has put together an entire open-sourced smart enclosure for most open concept printers.

While certain 3D printers or filament choices lend themselves to being worse than others, any type of plastic particles floating around shouldn’t find their way into your lungs. The [Clura] enclosure design includes HEPA and carbon filters in an attempt to remove this material from the air. Of course, there’s always the choice to have a tent around your printer, but this won’t actually remove any VOCs and air located inside a simple enclosure will inevitably escape.

What makes this enclosure different from other, either commercial or open-source designs, is the documentation included with the project. There are kits available for purchase, which you may want for the custom PCB boards for smart features such as filament weighing or fume detection. Even still, if you don’t want to purchase these custom boards the Gerber files are available on their GitHub page.

As smart as this enclosure is, it still won’t fix the issues of what happens to the toxins in your print after it’s done printing. If you are interested in this big picture question, you are not alone. Make sure to stay educated and help others learn by checking out this article here about plastic in our oceans.