EmuDevz Is Literally A Software Game

The idea of gamifying all the things might have died down now that the current hype is shoving AI into all the things — but you’ve probably never seen it quite like EmuDevz, a game in which you develop an 8-bit emulator by [Rodrigo Alfonso].

There’s a lot of learning you’ll have to do along the way, about programming and how retro systems work, including diving into 6502 assembly code. Why 6502? Well, the emulator you’re working on (it’s partially-written at the start of the game; you need only debug and finish the job) is for a fantasy system called the NEEES “an antique game console released in 1983”. It’s the NEEES and not NES for two reasons. One, Nintendo has lawyers and they really, really know how to use them. Two, by creating a fantasy console that is not-quite-a-Famicom, the goalposts for EmuDevz can be moved a bit closer in.

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Standalone CNC Tube Cutter/Notcher Does It With Plasma

Tubes! Not only is the internet a series of them, many projects in the physical world are, too. If you’re building anything from a bicycle to a race cart to and aeroplane, you might find yourself notching and welding metal tubes together. That notching part can be a real time-suck. [Jornt] from HOMEMADE MADNESS (it’s so mad you have to shout the channel name, apparently) thought so when he came up with this 3-axis CNC tube notcher.

If you haven’t worked with chrome-molly or other metal tubing, you may be forgiven for wondering what the big deal is, but it’s pretty simple: to get a solid weld, you need the tubes to meet. Round tubes don’t really want to do that, as a general rule. Imagine the simple case of a T-junction: the base of the T will only meet the crosspiece in a couple of discreet points. To get a solid joint, you have to cut the profile of the crosspiece from the end of the base. Easy enough for a single T, but for all the joins in all the angles of a space-frame? Yeah, some technological assistance would not go amiss.

Which is where [Jornt]’s project comes in. A cheap plasma cutter sits on one axis, to cut the tubes as they move under it. The second axis spins the tube, which is firmly gripped by urethane casters with a neat cam arrangement. The third axis slides the tube back and forth, allowing arbitarily long frame members to be cut, despite the very compact build of the actual machine. It also allows multiple frame members to be cut from a single long length of tubing, reducing setup time and speeding up the overall workflow. Continue reading “Standalone CNC Tube Cutter/Notcher Does It With Plasma”

BlueSCSI: Not Just For Apple

Anyone into retro Macintosh machines has probably heard of BlueSCSI: an RP2040-based adapter that lets solid state flash memory sit on the SCSI bus and pretend to contain hard drives. You might have seen it on an Amiga or an Atari as well, but what about a PC? Once upon a time, higher end PCs did use SCSI, and [TME Retro] happened to have one such. Not a fan of spinning platters of rust, he takes us through using BlueSCSI with a big-blue-based-box.

Naturally if you wish to replicate this, you should check the BlueSCSI docs to see if the SCSI controller in your PC is on their supported hardware list; otherwise, your life is going to be a lot more difficult than what is depicted on [TME Retro]. As is, it’s pretty much the same drop-in experience anyone who has used BlueSCSI on a vintage Macintosh might expect. Since the retro-PC world might not be as familiar with that, [TME Retro] gives a great step-by-step, showing how to set up hard disk image files and an iso to emulate a SCSI CD drive on the SD card that goes into the BlueSCSIv2.

This may not be news to some of you, but as the title of this video suggests, not everyone knows that BlueSCSI works with PCs now, even if it has been in the docs for a while. Of course PCs owners are more likely to be replacing an IDE drive; if you’d rather use a true SSD on that bus, we’ve got you covered.

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SLM Co-extruding Hotend Makes Poopless Prints

Everyone loves colourful 3D prints, but nobody loves prime towers, “printer poop” and all the plastic waste associated with most multi-material setups. Over the years, there’s been no shortage of people trying to come up with a better way, and now it’s time for [Roetz] to toss his hat into the ring, with his patent-proof, open-source Roetz-End. You can see it work in the video below.

The Roetz-End is, as you might guess, a hot-end that [Roetz] designed to facilitate directional material printing. He utilizes SLM 3D printing of aluminum to create a four-in-one hotend, where four filaments are input and one filament is output. It’s co-extrusion, but in the hot-end and not the nozzle, as is more often seen. The stream coming out of the hot end is unmixed and has four distinct coloured sections. It’s like making bi-colour filament, but with two more colours, each aligned with one possible direction of travel of the nozzle.

What you get is ‘directional material deposition’: which colour ends up on the outer perimeter depends on how the nozzle is moving, just like with bi-color filaments– though far more reliably. That’s great for making cubes with distinctly-coloured sides, but there’s more to it than that. Printing at an angle can get neighboring filaments to mix; he demonstrates how well this mixing works by producing a gradient at (4:30). The colour gradients and combinations on more complicated prints are delightful.

Is it an MMU replacement? Not as-built. Perhaps with another axis– either turning the hot-end or the bed to control the direction of flow completely, so the colours could mix however you’d like, we could call it such. That’s discussed in the “patent” section of the video, but has not yet been implemented. This technique also isn’t going to replace MMU or multitool setups for people who want to print dissimilar materials for easily-removable supports, but co-extruding materials like PLA and TPU in this device creates the possibility for some interesting composites, as we’ve discussed before.

As for being “patent-proof” — [Roetz] believes that through publishing his work on YouTube and GitHub into the public domain, he has put this out as “prior art” which should block any entity from successfully filing a patent. It worked for Robert A. Heinlein with the waterbed, but that was a long time ago. Time will tell if this is a way to revive open hardware in 3D printing.

It’s certainly a neat idea, and we thank [CityZen] for the tip.

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Your LLM Won’t Stop Lying Any Time Soon

Researchers call it “hallucination”; you might more accurately refer to it as confabulation, hornswaggle, hogwash, or just plain BS. Anyone who has used an LLM has encountered it; some people seem to find it behind every prompt, while others dismiss it as an occasional annoyance, but nobody claims it doesn’t happen. A recent paper by researchers at OpenAI (PDF) tries to drill down a bit deeper into just why that happens, and if anything can be done.

Spoiler alert: not really. Not unless we completely re-think the way we’re training these models, anyway. The analogy used in the conclusion is to an undergraduate in an exam room. Every right answer is going to get a point, but wrong answers aren’t penalized– so why the heck not guess? You might not pass an exam that way going in blind, but if you have studied (i.e., sucked up the entire internet without permission for training data) then you might get a few extra points. For an LLM’s training, like a student’s final grade, every point scored on the exam is a good point. Continue reading “Your LLM Won’t Stop Lying Any Time Soon”

PLA Gears Fail To Fail In 3D Printed Bicycle Drivetrain

Anyone who has ever snapped a chain or a crank knows how much torque a bicycle’s power train has to absorb on a daily basis; it’s really more than one might naively expect. For that reason, [Well Done Tips]’s idea of 3D printing a gear chain from PLA  did not seem like the most promising of hacks to us.

Contrary to expectations, though, it actually worked; at the end of the video (at about 13:25), he’s on camera going 20 km/h, which while not speedy, is faster than we thought the fixed gearing would hold up. The gears themselves, as you can see, are simple spurs, and were modeled in Fusion360 using a handy auto-magical gear tool. The idler gears are held in place by a steel bar he welded to the frame, and are rolling on good old-fashioned skateboard bearings–two each. (Steel ones, not 3D printed bearings.) The healthy width of the spur gears probably goes a long way to explaining how this contraption is able to survive the test ride.

The drive gear at the wheel is steel-reinforced by part of the donor bike’s cassette, as [Well Done Tips] recognized that the shallow splines on the freewheel hub were not exactly an ideal fit for PLA. He does complain of a squeaking noise during the test ride, and we can’t help but wonder if switching to helical gears might help with that. That or perhaps a bit of lubricant, as he’s currently riding the gears dry. (Given that he, too, expected them to break the moment his foot hit the pedal, we can’t hardly blame him not wanting to bother with grease.)

We’ve seen studies suggesting PLA might not be the best choice of plastic for this application; if this wasn’t just a fun hack for a YouTube video, we’d expect nylon would be his best bet. Even then, it’d still be a hack, not a reliable form of transportation. Good thing this isn’t reliable-transportation-a-day!

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Motors Make The Best Knobs With SimpleFOC

The worst thing about a volume knob is that, having connected it to a computer, it might be wrong: if you’ve manually altered the volume settings somewhere else, the knob’s reading won’t be correct. [I Got Distracted] has a quick tutorial on YouTube showing how to use a BLDC, a hall effect sensor, Pi Pico and the SimpleFOC library to make a knob with active haptic feedback and positioning.

We covered the SimpleFOC library a few years ago, but in case you missed it, it’s, well, a simple library for FOC on all of our favorite microcontrollers, from Arduino to ESP to Pico. FOC stands for field-oriented control, which is a particular way of providing smooth, precise control to BLDCs. (That’s a BrushLess DC motor, if the slightly-odd acronym is new to you.) [I Got Distracted] explains exactly how that works, and shows us just how simple the SimpleFOC project is to use in this video.  Why, they even produce their own motor controllers, for a fully-integrated experience. (You aren’t restricted to that hardware, but it certainly does make things easy.)

The haptic feedback and self-dialing knob make for an easy introductory project, but seeing how quick it hacks together, you can doubtless think of other possibilities. The SimpleFOC controller used in this video is limited to relatively small motors, but if you want to drive hundreds of kilowatts through open source hardware, we’ve covered that, too.  

Arguably, using a motor as a knob isn’t within the design spec, and so could almost qualify for our ongoing Component Abuse Challenge, had [I Got Distracted] thought to enter.

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