If you ever built a line following robot, you’ll be nostalgic about [Jeremy’s] light-seeking robot. It is a very simple build since there is no CPU and, therefore, also no software.
The trick, of course, is a pair of photo-sensitive resistors. A pair of motors turns the robot until one of the sensors detects light, then moves it forward.
How do you go about making a mirror with 128 segments, each of which can be independently angled? That was the question that a certain bloke over at [Time Sink Studio] found himself pondering on, to ultimately settle on a whole batch of mini-actuators bought through AliExpress. These stepper-based actuators appear to be akin to those used with certain Oppo smartphones with pop-up camera, costing less than half a dollar for a very compact and quite fast actuator.
The basic design is very much akin to a macro version of a micromirror device, as used in e.g. DLP projectors, which rely on a kinetic mirror mount to enable precise alignment. With the small actuators travelling up to 8 mm each, the mirrors can cover 73 mm at a distance of 4 meters from a wall.
With the required angle of the mirror being effectively just the application of the Pythagorean theorem, the biggest challenge was probably calibrating these linear motors. Since they’re open loop devices, they are zeroed much like the steppers on 3D printers, by finding the end limit and counting steps from that known point. This doesn’t make drift impossible, but for projecting light onto walls it’s clearly more than good enough.
Continue reading “How To Use Tiny Open Loop Actuators For A Living Mirror”
Syringes are pretty ergonomic, but when manually dispensing flux and solder paste it doesn’t take long before one wants a better way. [Elektroarzt]’s flux and solder paste dispenser design uses 3D-printed parts and minimal hardware (mostly M3x20 screws, and an optional spring) to improve handling and control.
How does it work? The ratcheting lever mechanism is similar to that of a hot glue gun, where an arm slips into notches in a rod when pressed down, driving it forward and never backward. In the process, a larger lever movement is translated into a shorter plunger travel, enhancing control.
The types of syringes this tool is meant to be used with have a plunger tip or piston (the rubber stopper-looking part, in contact with the liquid) inside the loaded syringe, but no plunger shaft attached to it. This is common with syringes meant to be loaded into tools or machines, and [Elektroarzt]’s tool can be used with any such syringe in a 10 cc size.
It’s an attractive design, and we like the way syringes top-load as well as the way the tool is made to lay flat on a tabletop, with the lever pointed up.
Want truly fine-grained control over your extrusions? Then check out this dispenser which really lets one dial in small amounts. You can also go motorized, and let a small PCB and stepper motor do the work.
Get a handle on this bad boy! Okay, so those voids are really more for airing out your palms, I’d imagine, because palm sweat sure is real — you should see the pads of my Kinesis. This kind of looks like two sawed-off machine guns kissing, and I mean that in the best possible and non-violent way.
And yet, pricing (oh yeah, this is gonna be A Thing You Can Buy) will be around $115-155, depending upon whether you want the base kit, or the add-ons, too, minus switches and key caps.
So let’s get into the particulars here. As you can see, there are key wells and thumb clusters, inspired by other keyboards including your bog standard Maltrons, Kinesis Advantages and more modern, open-source takes like the Dactyl. [ntc490] loves the key well-thumb cluster combination, and I do, too (hello from the Glove80). And miraculously, the keys are hot-swappable via sockets.
Inside, you’d find direct wiring to the GPIOs, so I’m gonna guess that those are RP2040 clones in there. There’s no PCB, no diodes, no matrices to debug.
So please do go visit the thread if this keyboard appeals to you at this price point. I love it, but I would need more rows of keys, personally. The top reddit comment mentions this as well, and [ntc490] says that because the thing is modular, it can easily accommodate more keys in both the wells and the thumb clusters. I seriously want one of these. Just with a few more keys.
Continue reading “Keebin’ With Kristina: The One With The Ball-Joint Keyboard”
Although arguably redundant on a typical computer keyboard, the idea of embedding small screens into the buttons on devices like audio production gear that often have so many buttons can make a lot of sense. As exemplified by devices with a UX that regularly degrades into scrolling through options on a tiny screen. This was basically the impetus for [Craig J Bishop] a few years ago to set out on a design project called the SoundSlab audio sequencer/sampler/synthesizer and slab that would make those buttons much more functional.
Obviously, the right way to start the project is to bulk buy hundreds of 0.85″ 128×128 LCDs so that you’re firmly locked into that choice. Fortunately, it turned out that the most annoying part of this LCD was the non-standard 0.7 mm pitch on its flat flex cable (FFC). This was worked around with an PCB adapter milled out of some copper-clad FR-1, which gave it a convenient PMOD interface for straightforward hook-up to a Xilinx Artix-7 FPGA board.
The buttons themselves were designed as 3D printed key caps for the LCDs that clipped onto typical Cherry MX-style mechanical keys. This also revealed that the original FFCs were too short, so they had to be replaced with new FFCs, that also adapted it to a standard 0.5 mm pitch. With this a 4×4 button prototype board could be constructed for testing.
Since that prototype [Craig] has built a full-sized SoundSlab grid, with a custom FPGA board and HDMI input, of which a preview can be seen in the post, along with a promise by [Craig] to soon post the rest of the SoundSlab development.
Thanks to [JohnS_AZ] for the tip.
The Internet has spoiled us. You assume network packets either show up pretty quickly or they are never going to show up. Even if you are using WiFi in a crowded sports stadium or LTE on the side of a deserted highway, you probably either have no connection or a fairly robust, although perhaps intermittent, network. But it hasn’t always been that way. Radio networks, especially, used to be very hit or miss and, in some cases, still are.
Perhaps the least reliable network today is one connecting things in deep space. That’s why NASA has a keen interest in Delay Tolerant Networking (DTN). Note that this is the name of a protocol, not just a wish for a certain quality in your network. DTN has been around a while, seen real use, and is available for you to use, too.
Think about it. On Earth, a long ping time might be 400 ms, and most of that is in equipment, not physical distance. Add a geostationary orbital relay, and you get 600 ms to 800 ms. The moon? The delay is 1.3 sec. Mars? Somewhere between 3 min and 22 min, depending on how far away it is at the moment. Voyager 1? Nearly a two-day round trip. That’s latency!
Washington State’s House Bill 2321 is currently causing a bit of an uproar, as it seeks to add blocking technologies to 3D printers, in order to prevent them from printing “a firearm or illegal firearm parts”, as per the full text. Sponsored by a sizeable number of House members, it’s currently in committee, so the likelihood of it being put to a floor vote in the House is still remote, never mind it passing the Senate. Regardless, it is another chapter in the story of homemade firearms, which increasingly focuses on private 3D printers.
Also called ‘ghost guns‘ in the US, these can be assembled from spare parts, from kits, from home-made components, or a combination of these. While the most important parts of a firearm, like the barrel, have to be made out of something like metal, the rest can feature significant amounts of plastic parts, though the exact amount varies wildly among current 3D-printed weapons.
Since legally the receiver and frame are considered to be ‘firearms’, these are the focus of this proposed bill, which covers both additive and subtractive technology. The proposal is that a special firearms detection algorithm has to give the okay for the design files to be passed on to the machine.
Continue reading “Washington State Bill Seeks To Add Firearms Detection To 3D Printers”
