From the very dawn of the personal computing era, the PC and Apple platforms have gone very different ways. IBM compatibles surged in popularity, while Apple was able to more closely guard the Macintosh from imitators wanting to duplicate its hardware and run its software.
Things changed when Apple announced it would hop aboard the x86 bandwagon in 2005. Soon enough was born the Hackintosh. It was difficult, yet possible, to run MacOS on your own computer built with the PC parts your heart desired.
In the comments of a recent article, the question came up as to where to find projects from the really smart kids the greybeards remember being in the 70s. In the case of [Will Dana] the answer is YouTube, where he’s done an excellent job of producing an ISS-tracking lamp, especially considering he’s younger than almost all of the station’s major components.*
There’s nothing ground-breaking here, and [Will] is honest enough to call out his inspiration in the video. Choosing to make a ground-track display with an off-the-shelf globe is a nice change from the pointing devices we’ve featured most recently. Inside the globe is a pair of stepper motors configured for alt/az control– which means the device must reset every orbit, since [Willis] didn’t have slip rings or a 360 degree stepper on hand. A pair of magnets couples the motion system inside the globe to the the 3D printed ISS model (with a lovely paintjob thanks to [Willis’s girlfriend]– who may or may be from Canada, but did show up in the video to banish your doubts as to her existence), letting it slide magically across the surface. (Skip to the end of the embedded video for a timelapse of the globe in action.) The lamp portion is provided by some LEDs in the base, which are touch-activated thanks to some conductive tape inside the 3D printed base.
It’s all controlled by an ESP32, which fetches the ISS position with a NASA API. Hopefully it doesn’t go the way of the sighting website, but if it does there’s more than enough horsepower to calculate the position from orbital parameters, and we are confident [Will] can figure out the code for that. That should be pretty easy compared to the homebrew relay computer or the animatronic sorting hat we featured from him last year.
Commercial 3D printers keep getting faster and faster, but we can confidently say that none of them is nearly as fast as [Jan]’s Minuteman printer, so named for its goal of eventually printing a 3DBenchy in less than a minute. The Minuteman uses an air bearing as its print bed, feeds four streams of filament into one printhead for faster extrusion, and in [Jan]’s latest video, printed a Benchy in just over two minutes at much higher quality than previous two-minute Benchies.
[Jan] found that the biggest speed bottleneck was in cooling a layer quickly enough that it would solidify before the printer laid down the next layer. He was able to get his layer speed down to about 0.6-0.4 seconds per layer, but had trouble going beyond that. He was able to improve the quality of his prints, however, by varying the nozzle temperature throughout the print. For this he used [Salim BELAYEL]’s postprocessing script, which increases hotend temperature when volumetric flow rate is high, and decreases it when flow rate is low. This keeps the plastic coming out of the nozzle at an approximately constant temperature. With this, [Jan] could print quite good sub-four and sub-thee minute Benchies, with almost no print degradation from the five-minute version. [Jan] predicts that this will become a standard feature of slicers, and we have to agree that this could help even less speed-obsessed printers.
Now onto less generally-applicable optimizations: [Jan] still needed stronger cooling to get faster prints, so he designed a circular duct that directed a plane of compressed air horizontally toward the nozzle, in the manner of an air knife. This wasn’t quite enough, so he precooled his compressed air with dry ice. This made it both colder and denser, both of which made it a better coolant. The thermal gradient this produced in the print bed seemed to cause it to warp, making bed adhesion inconsistent. However, it did increase build quality, and [Jan]’s confident that he’s made the best two-minute Benchy yet.
If you’re curious about Minuteman’s motion system, we’ve previously looked at how that was built. Of course, it’s also possible to speed up prints by simply adding more extruders.
