Today we're ecstatic to publish our first demo showing a homemade BusKill Cable (in the prototype 3D-printed case) triggering a lockscreen.

| [!3D-Printed USB Dead Man Switch (Prototype Demo)](https://www.buskill.in/3d-print-2024-05/) | |:--:| | Watch the 3D-Printed USB Dead Man Switch (Prototype Demo) for more info youtube.com/v/vFTQatw94VU |

via @Goldfishlaser@lemmy.ml

In our last update, I showed a video demo where I successfully triggered a lockscreen using a BusKill prototype without the 3D-printed body for the case and N35 disc magnets. I realized that the N35 disc magnets were not strong enough. In this update, I show a demo with the prototype built inside a 3D-printed case and with (stronger) N42 and N52 cube magnets.

What is BusKill?

BusKill is a laptop kill-cord. It's a USB cable with a magnetic breakaway that you attach to your body and connect to your computer.

| [!What is BusKill? (Explainer Video)](https://www.buskill.in/#demo) | |:--:| | Watch the BusKill Explainer Video for more info youtube.com/v/qPwyoD_cQR4 |

If the connection between you to your computer is severed, then your device will lock, shutdown, or shred its encryption keys -- thus keeping your encrypted data safe from thieves that steal your device.

Why?

While we do what we can to allow at-risk folks to purchase BusKill cables anonymously, there is always the risk of interdiction.

We don't consider hologram stickers or tamper-evident tape/crisps/glitter to be sufficient solutions to supply-chain security. Rather, the solution to these attacks is to build open-source, easily inspectable hardware whose integrity can be validated without damaging the device and without sophisticated technology.

Actually, the best way to confirm the integrity of your hardware is to build it yourself. Fortunately, BusKill doesn't have any circuit boards, microcontrollers, or silicon; it's trivial to print your own BusKill cable -- which is essentially a USB extension cable with a magnetic breakaway in the middle

Mitigating interdiction via 3D printing is one of many reasons that Melanie Allen has been diligently working on prototyping a 3D-printable BusKill cable this year. In this article, we hope to showcase her progress and provide you with some OpenSCAD and .stl files you can use to build your own version of the prototype, if you want to help us test and improve the design.

Print BusKill

[!Photo of the 3D-Printed BusKill Prototype](https://www.buskill.in/3d-print-2024-05/)

If you'd like to reproduce our experiment and print your own BusKill cable prototype, you can download the stl files and read our instructions here:

• buskill.in/3d-print-2024-05

Iterate with us!

If you have access to a 3D Printer, you have basic EE experience, or you'd like to help us test our 3D printable BusKill prototype, please let us know. The whole is greater than the sum of its parts, and we're eager to finish-off this 3D printable BusKill prototype to help make this security-critical tool accessible to more people world-wide!

I've noticed for awhile now that whenever my Ender 3 S1 Pro is running, some of the lights on the same circuit will flicker seemingly in time with changes in X or Y stage movement. I'd guess that it's a combination of these stages causing minor voltage spikes/dips when they accelerate, and certain cheaper LED bulbs don't tolerate those spikes/dips well.

Has anyone else experienced this and implemented a good fix? It seems like some kind of power smoothing/conditioning filter plugged in between the printer and the wall would help isolate it. Most of those devices seem designed to isolate the device from fluctuations in the mains, and I'm not sure if it generally works both ways (seems like it should...)

Googling around most people are blaming similar issues on poor wiring, which I suppose could be the case even though this is a newer house. But I see very little in terms of actual proven effective fixes, even though it sounds pretty straightforward on its face.

Advice / thoughts?

STL: https://www.thingiverse.com/thing:1032216

Printing some PETG did not go as planned

I'm planning to print up a bunch of brackets to mount LED shop lights (very similar to these) to the ceiling in my garage. My plan is to use an upside-down "U" shape bracket that screws into a joist/drywall anchor in the middle and then sort of clips around the sides of the metal frame.

Maybe filament type doesn't matter much here, but I'd rather not come out to one of the lights having fallen on my car if I can help it 😅

I think the main considerations are just temperature and stiffness. It can get up to about 85F in the garage on the hottest summer days, and probably a few degrees warmer by the ceiling. The lamps are cheap LED tubes, so the metal housing only gets slightly warm to the touch (say 90-100F or so). I know PLA is a bit stiffer at room temp, but I'm worried it might soften too much at the worst case of warm temperatures.

Any thoughts on PLA vs PETG for this situation?

I'm mostly into printing functional stuff. Last thing I designed and printed was a fume extractor for soldering.