Hackaday Links: August 25, 2019

Doesn’t the Z-axis on 3D-printers seem a little – underused? I mean, all it does is creep up a fraction of a millimeter as the printer works through each slice. It would be nice if it could work with the other two axes and actually do something interesting. Which is exactly what’s happening in the nonplanar 3D-printing methods being explored at the University of Hamburg. Printing proceeds normally up until the end, when some modifications to Slic3r allow smooth toolpaths to fill in the stairsteps and produce a smooth(er) finish. It obviously won’t work for all prints or printers, but it’s nice to see the Z-axis finally pulling its weight.

If you want to know how something breaks, best to talk to someone who looks inside broken stuff for a living. [Roger Cicala] from LensRentals.com spends a lot of time doing just that, and he has come to some interesting conclusions about how electronics gear breaks. For his money, the prime culprit in camera and lens breakdowns is side-mounted buttons and jacks. The reason why is obvious once you think about it: components mounted perpendicular to the force needed to operate them are subject to a torque. That’s a problem when the only thing holding the component to the board is a few SMD solder pads. He covers some other interesting failure modes, too, and the whole article is worth a read to learn how not to design a robust product.

In the seemingly neverending quest to build the world’s worst Bitcoin mining rig, behold the 8BitCoin. It uses the 6502 processor in an Apple ][ to perform the necessary hashes, and it took a bit of doing to port the 32-bit SHA256 routines to an 8-bit platform. But therein lies the hack. But what about performance? Something something heat death of the universe…

Contributing Editor [Tom Nardi] dropped a tip about a new online magazine for people like us. Dubbed Paged Out!, the online quarterly ‘zine is a collection of contributed stories from hackers, programmers, retrocomputing buffs, and pretty much anyone with something to say. Each article is one page and is formatted however the author wants to, which leads to some interesting layouts. You can check out the current issue here; they’re still looking for a bunch of articles for the next issue, so maybe consider writing up something for them – after you put it on Hackaday.io, of course.

Tipline stalwart [Qes] let us know about an interesting development in semiconductor manufacturing. Rather than concentrating on making transistors smaller, a team at Tufts University is making transistors from threads. Not threads of silicon, or quantum threads, or threads as a metaphor for something small and high-tech. Actual threads, like for sewing. Of course, there’s plenty more involved, like carbon nanotubes — hey, it was either that or graphene, right? — gold wires, and something called an ionogel that holds the whole thing together in a blob of electrolyte. The idea is to remove all rigid components and make truly flexible circuits. The possibilities for wearable sensors could be endless.

And finally, here’s a neat design for an ergonomic utility knife. It’s from our friend [Eric Strebel], an industrial designer who has been teaching us all a lot about his field through his YouTube channel. This knife is a minimalist affair, designed for those times when you need more than an X-Acto but a full utility knife is prohibitively bulky. [Eric’s] design is a simple 3D-printed clamshell that holds a standard utility knife blade firmly while providing good grip thanks to thoughtfully positioned finger depressions. We always get a kick out of watching [Eric] design little widgets like these; there’s a lot to learn from watching his design process.

Thanks to [JRD] and [mgsouth] for tips.

Add A Microscope To Your 3D Printer

There are many ways to keep an eye on your 3D printer as it churns out the layers of your print. Most of us take a peek every now and then to ensure we’re not making plastic vermicelli, and some of us will go further with a Raspberry Pi camera or similar. [Uri Shaked] has taken this a step further, by adding a USB microscope on a custom bracket next to the hot end of his Creality Ender 3.

The bracket is not in itself anything other than a run-of-the-mill piece of 3D printing, but the interest comes in what can be done with it. The Ender 3 has a resolution of 12.5μm on X/Y axes, and 2.5μm on Z axes, meaning that the ‘scope can be positioned to within a hair’s-breadth of any minute object. Of course this achieves the primary aim of examining the integrity of 3D prints, but it also allows any object to be tracked or scanned with the microscope.

For example while examining a basil leaf, [Uri] noticed a tiny insect on its surface and was able to follow it with some hastily entered G-code. Better still, he took a video of the chase, which you can see below the break. From automated PCB quality control to artistic endeavours, we’re absolutely fascinated by the possibilities of a low-cost robotic microscope platform.

[Uri] is a perennial among Hackaday-featured projects, and has produced some excellent work over the years. Most recently we followed him through the production of an event badge.

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I Love The Smell Of ABS Plastic In The Morning

One lesson we can learn from the Vietnam War documentary Apocalypse Now is that only crazy people like terrible smells just for fun. Surely Lt. Col. Kilgore would appreciate the smell of 3D printers as well, but for those among us who are a little less insane, we might want a way to eliminate the weird (and not particularly healthy) smell of melting ABS plastic.

While a simple solution would be a large fume hood or a filter to prevent inhaling the fumes, there are more elegant solutions to this problem. [Mark]’s latest project uses an electrostatic precipitator (ESP) to remove the volatile plastic particles from the air. Essentially it is a wire with a strong voltage applied to it enclosed in a vessel of some sort. The voltage charges particles, which then travel to a collecting electrode. Commercial offerings also include an X-ray generator to help clean the air, but [Mark] found this to be prohibitively expensive.

The ESP is built into a small tube through with the air can flow, and the entire device itself is housed in the printing enclosure. The pictures show the corona discharge in the device, and [Mark] plans to test it over the next few months to determine its effectiveness. He does note, however, that the electrostatic discharge creates ozone, which has its own set of problems, so he recommends against building one on your own. Ozone at least still smells like victory.

Trash Printer Directly Uses Recycled Plastics

3D printing is all well and good, but it can get expensive having to purchase roll after roll of filament. Various projects exist that attempt to take unwanted 3D prints and turn them back into filament to be used again. However, [Sam Smith] took a different path. The Trash Printer is a 3D print head that works with recycled plastic, with less intermediate processing steps.

The Trash Printer is a print head is intended to work with shredded plastics directly, rather than by first turning them back into a filament. Thus far, [Sam] has tested the Polypropylene and HDPE, and results are promising. While the prints aren’t of the same quality as using pre-prepared filament, the parts are still viable and fit for purpose.

The print head consists of an auger, along with a cartridge heater, which work together to push plastic to the print head. The head is constructed out of laser-cut parts and a few off-the-shelf components, making it easy to replicate. [Sam] has spent significant time honing the design, and has several ideas for ways in which it could be developed further. We’re eager to see how far this technology can go, and can’t wait to see what comes next. We’ve seen other attempts to recycle plastics for 3D printing, too. Expect to see further developments in this space coming thick and fast.

Creating A Laser Cutter From A 3D Printer

The average FDM 3D printer is not so different from your garden variety laser cutter. They’re often both Cartesian-coordinate based machines, but with different numbers of axes and mounting different tools. As [Gosse Adema] shows, turning a 3D printer into a laser cutter can actually be a remarkably easy job.

The build starts with an Anet A8 3D printer. It’s an affordable model at the lower end of the FDM printer market, making it accessible to a broad range of makers. With the help of some 3D printed brackets, it’s possible to replace the extruder assembly with a laser instead, allowing the device to cut and engrave various materials.

[Gosse] went with a 5500 mW diode laser, which allows for the cutting and engraving of wood, some plastics and even fabrics. Unlike a dedicated laser cutter there are no safety interlocks and no enclosure, so it’s important to wear goggles when the device is operating. Some tinkering with G-Code is required to get things up and running, but it’s a small price to pay to get a laser cutter on your workbench.

We’ve seen [Gosse]’s 3D printer experiments before, with the Anet A8 serving well as a PCB milling machine.

Autodrop3D Continues Working At 3D Printer Automation

It is an unfortunate fact that 3D printers spend most of their time sitting idle, waiting for a human to remove finished prints or waiting for the next print to start. Hackers see such inefficiency as an open invitation to devise a better way, and we’ve seen several innovative ideas come across these pages. Some have since been abandoned, but others have kept going. At Maker Faire Bay Area 2019 we had the chance to revisit one presented as Autodrop3D.

We saw a much earlier iteration entered in our Hackaday Prize in 2017 and it was fascinating to see how the basic ideas have developed over the past few years. The most visible component of the system is their print ejection system, which has greatly improved in robustness. Because the mechanism modifies the print bed and adds significant mass, it is best suited to delta printers as their print bed remains static. The concept might be adaptable to printers where the print bed only has to move along Z axis, but for now the team stays focused on deltas. There were two implementations on display at Maker Faire: a large one built on a SeeMeCNC RostockMAX v4, and a small one built on a Monoprice Mini Delta.

The ejection system is novel enough by itself, but the hardware is only one part of the end-to-end Autodrop3D vision. Their full software pipeline starts with web-based CAD, to integrated slicing, to print queue management, before G-code is fed to a printer equipped with their ejection system.

We admire inventors who keep working away at turning their vision to reality, and we look forward to seeing what’s new the next time we meet this team. In the meantime, if you like the idea of an automated print ejection mechanism but want more cartoon style, look at this invention from MatterHackers.

Assessing Nozzle Wear In 3D-Printers

How worn are your nozzles? It’s a legitimate question, so [Stefan] set out to find out just how bad 3D-printer nozzle wear can get. The answer, as always, is “It depends,” but exploring the issue turns out to be an interesting trip.

Reasoning that the best place to start is knowing what nozzle wear looks like, [Stefan] began by printing a series of Benchies with brand-new brass nozzles of increasing diameter, to simulate wear. He found that stringing artifacts, interlayer holes, and softening of overhanging edges and details all worsened with increasing nozzle size. Armed with this information, [Stefan] began a torture test of some cheap nozzles with both carbon-fiber filament and a glow-in-the-dark filament, both of which have been reported as nozzle eaters. [Stefan] found that to be the case for at least the carbon-fiber filament, which wore the nozzle to a nub after extruding only 360 grams of material.

Finally, [Stefan] did some destructive testing by cutting used nozzles in half on the mill and looking at them in cross-section. The wear on the nozzle used for carbon-fiber is dramatic, as is the difference between brand-new cheap nozzles and the high-quality parts. Check out the video below and please sound off in the comments if you know how that peculiar spiral profile was machined into the cheap nozzles.

Hats off to [Stefan] for taking the time to explore nozzle wear and sharing his results. He certainly has an eye for analysis; we’ve covered his technique for breaking down 3D-printing costs in [Donald Papp]’s  “Life on Contract” series.

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