[Victor]’s nifty tool the Solder Scroll is a handheld device that lets one feed solder out simply by turning something a little like a scroll wheel. It looks like an intuitive and comfortable design that can adapt to a wide variety of solder thicknesses, and is entirely 3D printed.
One part we particularly like is the feed system. One rolls a wheel which feeds solder out using a mechanism a lot like extrusion gears in many 3D printer hot ends. Both wheels have ridged surfaces that grip and feed the solder; their gears mesh with one another so that moving one moves both in unison.
Solder feed tools like this have seen all kinds of interesting designs, because while the problem is the same for everyone, there are all kinds of different ways to go about addressing it. We love this one, and we have seen many other takes that range from a powered, glove-mounted unit to an extremely simple tool with no moving parts. We’ve even seen a method of hacking a mechanical pencil into a new role as a solder feeder.
[Peter Holderith] set out some time ago to build an electric go-kart. That by itself is not terribly unusual, but where his project diverts from the usual is in the fact that each of the four wheels has an integrated hub motor.
It might not look it, but each wheel has an integrated hub motor.
This kart project is a bit of a work in progress, with [Peter] previously building (then scrapping) a failed attempt at a cheap suspension system. But it’s completely operational with all four wheels able to deliver a monstrous amount of power despite being limited by the power supply (a battery pack salvaged from an Audi Q5 Hybrid).
The kart might not look it, but it weighs 177 pounds (80 kg) with the battery and motors accounting for nearly half of that. What is is like to drive? “Nothing short of thrilling,” says [Peter]. It’s got no suspension and is pretty bare bones, not to mention limited in power by the battery, but [Peter] finds it a satisfying drive that nevertheless delivers car-like cues in the driving experience. The build isn’t done, and [Peter] plans to see if more power is available by switching battery chemistries rather than add more battery weight.
Building and driving electric vehicles can be remarkably satisfying, and it’s an area in which hobbyists can meaningfully innovate. Self-balancing one-wheeled vehicles for example look like a ton of fun. Heck, researchers have discovered that even rats seem to enjoy driving just for the fun of it.
Apple has developed a proprietary — even mysterious — “fisheye” projection format used for their immersive videos, such as those played back by the Apple Vision Pro. What’s the mystery? The fact that they stream their immersive content in this format but have provided no elaboration, no details, and no method for anyone else to produce or play back this format. It’s a completely undocumented format and Apple’s silence is deafening when it comes to requests for, well, anything to do with it whatsoever.
Probably those details are eventually forthcoming, but [Mike Swanson] isn’t satisfied to wait. He’s done his own digging into the format and while he hasn’t figured it out completely, he has learned quite a bit and written it all up on a blog post. Apple’s immersive videos have a lot in common with VR180 type videos, but under the hood there is more going on. Apple’s stream is DRM-protected, but there’s an unencrypted intro clip with logo that is streamed in the clear, and that’s what [Mike] has been focusing on.
Most “fisheye” formats are mapped onto square frames in a way similar to what’s seen here, but this is not what Apple is doing.
[Mike] has been able to determine that the format definitely differs from existing fisheye formats recorded by immersive cameras. First of all, the content is rotated 45 degrees. This spreads the horizon of the video across the diagonal, maximizing the number of pixels available in that direction (a trick that calls to mind the heads in home video recorders being tilted to increase the area of tape it can “see” beyond the physical width of the tape itself.) Doing this also spreads the center-vertical axis of the content across the other diagonal, with the same effect.
There’s more to it than just a 45-degree rotation, however. The rest most closely resembles radial stretching, a form of disc-to-square mapping. It’s close, but [Mike] can’t quite find a complete match for what exactly Apple is doing. Probably we’ll all learn more soon, but for now Apple isn’t saying much.
Videos like VR180 videos and Apple’s immersive format display stereoscopic video that allow a user to look around naturally in a scene. But to really deliver a deeper sense of presence and depth takes light fields.
[Wendy] asked a very good question. Could putting liquid resin into an ultrasonic cleaner help degas it? Would it help remove bubbles, resulting in a cleaner pour and nicer end product? What we love is that she tried it out and shared her results. She purchased an ultrasonic cleaner and proceeded to mix two batches of clear resin, giving one an ultrasonic treatment and leaving the other untouched as a control.
Sadly, the test piece had considerably more surface bubbles than the untreated control, as well as a slight discoloration.
The results were interesting and unexpected. Initially, the resin in the ultrasonic bath showed visible bubbles rising to the surface which seemed promising. Unfortunately, this did not lead to fewer bubbles in the end product.
[Wendy]’s measurements suggest that the main result of putting resin in an ultrasonic bath was an increase in its temperature. Overheating the resin appears to have led to increased off-gassing and bubble formation prior to and during curing, which made for poor end results. The untreated resin by contrast cured with better color and much higher clarity. If you would like to skip directly to the results of the two batches, it’s right here at 9:15 in.
Does this mean it’s a total dead end? Maybe, but even if the initial results weren’t promising, it’s a pretty interesting experiment and we’re delighted to see [Wendy] walk through it. Do you think there’s any way to use the ultrasonic cleaner in a better or different way? If so, let us know in the comments.
This isn’t the first time people have tried to degas epoxy resin by thinking outside the box. We’ve covered a very cheap method that offered surprising results, as well as a way use a modified paint tank in lieu of purpose-made hardware.
The usual way to put a durable threaded interface into a 3D print is to use a heat-set insert, but what about other options? [Thomas Sanladerer] evaluates a variety of different threaded inserts, none of which are actually made with 3D printing in mind but are useful nevertheless.
There are a number of other easily-available threaded inserts, including the rivnut (or rivet nut), chunky hex socket threaded inserts intended for wood and furniture, heli-coils or helical inserts (which resemble springs), self-tapping threaded inserts (also sold as thread adapters), and T-nuts or prong nuts. They all are a bit different, but he measures each one and gives a thorough rundown on how they perform, as well as offering his thoughts on what works best.
[Thomas] only tests M5 fasteners in this video, so keep that in mind if you get ideas and go shopping for new hardware. Some of the tested inserts aren’t commonly available in smaller sizes. Self-tapping threaded inserts, for example, are available all the way down to M2, but the hex socket threaded inserts don’t seem to come any smaller than M4.
The BBC Micro was many peoples’ first exposure to home computing, and thanks to [Dominic Pajak], you can fire up this beloved hardware in WebXR. Is it an emulator? Yes, but it’s also much more than that.
The machine, the CRT, the keycaps, and even the sounds of the original keypresses are all brought to life as accurately as possible. The result is not just an emulator. It’s a lovingly-made BBC Micro simulator you can use with a VR headset. Or just use your browser and type on your real keyboard if you like.
Some LLMs (Large Language Models) can act as useful programming assistants when provided with a project’s source code, but experimenting with this can get a little tricky if the chatbot has no way to download from the internet. In such cases, the code must be provided by either pasting it into the prompt or uploading a file manually. That’s acceptable for simple things, but for more complex projects, it gets awkward quickly.
To make this easier, [Eric Hartford] created github2file, a Python script that outputs a single text file containing the combined source code of a specified repository. This text file can be uploaded (or its contents pasted into the prompt) making it much easier to share code with chatbots.
One part we particularly like is the feed system. One rolls a wheel which feeds solder out using a mechanism a lot like extrusion gears in many 3D printer hot ends. Both wheels have ridged surfaces that grip and feed the solder; their gears mesh with one another so that moving one moves both in unison.
