sex super tubeSimply having a few go-to 3D printer motion system designs is no reason to stop exploring them, as even small iterations on an existing architecture can yield some tremendous improvements. In the last few months, both [Annex_Engineering] and [wesc23] have been piloting a rail-derived crossed gantry architecture, a “CroXY” as it’s come to be known. Borrowing concepts from Ultimaker’s crossed gantry using rods, the Hypercube Overkill project, and perhaps even each other, the results are two compact machine frames capable of beautiful prints at extremely high speeds–upwards of 400 mm/sec in [Annex_Engineering’s] case!
sex super tubeBoth gantry designs take a rotated MGN12 rail (a la the Railcore) and cross two of them, mounting the carriage at the intersection point much like an Ultimaker. Each crossed rail controls a degree of freedom with vanilla Cartesian kinematics, but each degree of freedom also has a redundant motor for added torque. Like the CoreXY design, this setup is tailored for clean prints at high speeds since the motion-related motors have been removed from the moving mass. However the overall belt length has been reduced tremendously, resulting in a much stiffer setup.
But the innovation doesn’t stop there. Both gantries also feature a unique take on a removable Z probe. When the machine needs to level the bed, it travels to a corner to “quickdraw” a magnetically attached limit switch from a holster. Once mounted, this probe becomes the lowest point on the carriage, allowing the carriage to travel around the bed probing points. When finished, the probe simply slots back into its holster, and the print can begin.
Both [wesc23’s] CroXY and a variant of [Annex_Engineering’s] K2 are up on Github complete with bills of materials if you’re curious to poke into the finer details. With commercial 3D printer manufacturers spending the last few years in a race to the bottom, it’s exciting to still see new design pattern contributions that push for quality and performance. For more design patterns contributions, have a look at [Mark Rehorst’s] Kinematically coupled bed design.
We might’ve thought that extrusion based 3D printers have hit their peak in performance capabilities. With the remaining process variables being tricky to model and control, there’s only so much we can expect on dimensional accuracy from extruded plastic processes. But what if we mixed machines, adding a second machining process to give the resulting part a machined quality finish? That’s exactly what the folks at E3D have been cooking up over the last few years: a toolchanging workflow that mixes milling and 3D printing into the same process to produce buttery smooth part finishes with tighter dimensional accuracy over merely 3D printing alone.
Dubbed ASMBL (Additive/Subtractive Machining By Layer), the process is actually the merging of two complimentary processes combined into one workflow to produce a single part. Here, vanilla 3D printing does the work of producing the part’s overall shape. But at the end of every layer, an endmill enters the workspace and trims down the imperfections of the perimeter with a light finishing pass while local suction pulls away the debris. This concept of mixing og coarse and fine manufacturing processes to produce parts quickly is a re-imagining of a tried-and-true industrial process called near-net-shape manufacturing.?However, unlike the industrial process, which happens across separate machines on a large manufacturing facility, E3D’s ASMBL takes place in a single machine that can change tools automatically. The result is that you can kick off a process and then wander back a few hours (and a few hundred tool changes) later to a finished part with machined tolerances.
What are the benefits of such an odd complimentary concoction, you might ask? Well, for one, truly sharp outer corners, something that’s been evading 3D printer enthusiasts for years, are now possible. Layer lines on vertical surfaces all but disappear, and the dimensional tolerances of holes increases as the accuracy of the process is more tightly controlled (or cleaned up!) yielding parts that are more dimensionally accurate… in theory.
Most folks that have been poking around at multi-tool 3D printing know that lining up nozzles can be a gnarly, but necessary pain point. Existing methods either have us measure offsets with a vernier scale or with a series of pictures taken with an upwards-facing camera. And this step is not to be ignored! Any mismatch between nozzles, and your multicolor prints end up looking like Scotty really screwed up those sliders on that transporter beam console. Fear not, however! [Danal] took this problem as an opportunity to write something that’s completely automated and brought to you by some machine vision.
Dubbed TAMV, for?Tool Align Machine Vision, [Danal] added a Raspberry Pi alongside his existing 3D printing motion controller in addition to an upwards facing camera. A few lines of code (and a few hours of compiling OpenCV) later, and he had himself a circle-detecting script that automatically cycles through each tool, detects the nozzle center, and calculates an offset for each tool that’s stored into the machine’s configuration file. If that’s not nifty enough, he’s made the entire setup open-source, and he included both an installation script for compiling OpenCV and a well-written set of step-by-step instructions.
In a world where most hobbyists approaches still solve this problem manually, this is leaps and bounds ahead of what we know, and it’s a great application of machine vision built on top of a stack of recognizable hardware and software. While this project was outfitted for a Jubilee running a Duet3 controller with a Raspberry Pi connected in “single-board computer” mode, the core features are readily adaptable to any other multi-tool machine with a similar control board stack. And for folks willing to poke under the hood, the project could even be extended to a standalone script that you can run on your PC locally to simply print the tool offsets separately.
Alongside TAMV, it’s refreshing that even a decade after 3D printers have been with us, we’re still finding ways to make these machines more capable. For more fresh hacks in this category, check out a new spin on using sharpie ink as a support material release agent.
Last week, [Danal Estes] passed away. This comes as a shock to many of us who had the pleasure of interacting with him online. Not only was [Danal] an active contributor to the 3D printing community, he was simply a warm-hearted character who was just fun to get along with. I met [Danal] online less than a year ago. But I owe him a debt in helping transform a set of design files that I posted online into a full blown community of hardware enthusiasts.
Here’s my best shot at recounting some of this fellow human’s legacy as seen from the fellow tool changing 3D printing enthusiasts who knew him.
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I first met [Danal] online last September through Thingiverse when he posted a make of Jubilee, a tool changing machine design that I posted a few weeks prior. At a time when Jubilee was just a set of files and instructions on the internet, I was stoked that someone in the world was out there building a duplicate. To get to know these people better and work out any pinch points in their assembly process, I started a Discord Chat Server. [Danal] was the first to join and start telling his story in pictures.
As a community of curious people on Discord grew, questions about the machine started to arise. How big was it? How did the tool changing work? I tried answering as many as I could, putting an FAQ blurb on Thingiverse, But a few weeks in, something else happened: [Danal] started answering the questions. Not only that, he was greeting nearly every single person who introduced themselves on the server. I didn’t understand the value of a simple “welcome aboard!” that follows someone’s first post in a budding online community, but [Danal] did. So he did just that. He made you feel welcome to have landed in this corner of the internet. In a world full of engineers who don’t like repeating themselves, [Danal] seemed to get that his repeat interaction was new for the person on the other end; and that made it worth doing.
As the days passed, questions continued, and [Danal] continued to fill people in with answers to questions–even repeat questions. All the while, he posted progress pictures of his own machine. In a way, the rest of the community seemed to be holding their breath during this time, watching [Danal] post status reports; waiting for some conviction that these files actually turned into something that worked. Then, less than a month later, [Danal] posted a video of his first successful tool change. It did work! Almost certainly inspired by [Danal’s] success, a few more folks started building machines of their own. But [Danal] was the first person to duplicate a Jubilee.
More than twenty machines have been built in the wild since I posted the project files back in September. I believe that the inspiration to start draws from the success of people who have finished before, which chains down to the inspiration drawn from the success of the first person to finish: [Danal Estes]. I owe him one for that: for inspiring a community of folks to follow in this adventure.
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[Danal] did more than affirm the machine design to a new Jubilee community. Over the short span of the project, [Danal] put his software hat on and developed an automated machine-vision based tool alignment system that he called TAMV. It turns out that tool tip calibration is one of the gnarly problems for any multi-nozzle 3D printer. Tools must be aligned relative to each other such that each of the unique materials they print are aligned in the resulting print. The current ways of doing this are cumbersome and manual. Either you measure offsets by printing a vernier scale or by taking pictures with an upwards-facing microscope. [Danal] took this gnarly problem as an opportunity to automate the process completely, so he did.
In just two months, [Danal] returned with an announcement on the Jubilee Discord to present TAMV, aka: Tool Align Machine Vision. By mounting an upwards facing webcam to the front of his Jubilee, [Danal] simply ran his one-button script, and his machine automatically calibrated each available tool both automatically and better than most humans could with the prior methods. It did this by sequentially picking up tools, putting them in the camera field of view, and then measuring their offsets. What’s more, he released the entire code base as open-source, literally transforming a gnarly problem into a thing of the past with a commodity solution made usable with a simple installation script and setup instructions that he also wrote.
Here on Hackaday, it’s humbling to read about the amazing feats folks are overcoming all from the comfort of their home workbenches. But it’s invigorating to see that same feat unfolded in a way that lets us unpack it, learn from it, build on top of it. The act of documenting work you’ve already done with the intent that others could follow it is an act of grace. [Danal] was gracious.
A Shared Story Told in Projects
As [Danal] became one of the most active community members on Discord, we started to learn more about his other projects. For [Danal], 3D printers were as much a side project as they were tools in a family of other tools for creative projects. Armed with these machines, [Danal] put them to work on machines for flight, from extraordinary remote control aircraft (3D printed of course) that could barely work their wingspan through a doorway to the consoles of real world aircraft that could carry a pilot.
It was always a pleasure to get a slice of [Danal’s] adventures. Getting to hear about his excitement in projecting was food for a growing community of hobbyists eager to get back to our workbenches. And the framing of his adventures was warm enough to make you feel not just that you wanted a bit of this lifestyle for yourself, but that you could have it too. I hope that this part of [Danal’s] legacy is something that we online folk can continue: the shared courtesy and warm attitude to newcomers in a hardware hacking community.
With everything from APIs to Raspberry Pis making it even easier for us to create and share objects shaped by personal whim, it’s high time that Don Norman’s sage design advice falls on not just the design student, but the hardware hacker and DIY enthusiast too. Grab yourself a coffee and a free weekend, and settle into the psychology of people-struggling-how-to-use-that-widget-they-just-purchased in The Design of Everyday Things: Revised and Expanded Edition.
Who’s to blame for a door that opens with a pull when everything about how it looks says it should open with a push? In Don Norman’s world, it’s not you; its the designer. Enter a world where blame is inverted and mistakes can be critically categorized. Norman takes us example by example showing us how common items in the world poorly serve the needs of their user, mainly because the designer simply ignores key aspects of our humanity. This book is a crisp, concise overview of human psychology when applied to engaging with things combined with a language of ideas to help us apply this psychology to better interactions. (And it reads like butter!)
Opening Up to the Language of Design
What’s an affordance, you might ask? Well, simply put, it’s a way that an object can be used by a human. How about a signifier? That’s a communication “signposting” scheme that object uses to suggest to you how it should be used. If that sounds a bit fluffy, just think about the last time you tried to push open a door that needed to be pulled. Something about that door was suggesting that you could push it open, but it couldn’t! It “fooled” you because all the object’s signifiers were telling you otherwise.
But Don Norman goes beyond a vocabulary that inverts our understanding of how we engage with objects and gives us another fresh perspective on how we make mistakes with out devices. Once again, these errors aren’t something to be ashamed of, but are categorizable interactions with our devices that, once understood, can be designed to accommodate or designed out altogether. Errors actually come in two large categories: mistakes?and?slips.?Mistakes are, by and large, errors in planning, and?slips are errors of action. Have you ever set your alarm for 7PM when you meant AM? That’s a slip. Or perhaps you forget some items on your grocery trip? That’s a mistake But there are actually multiple subcategories, each clearly explained with examples from real life, often accompanied by disastrous consequences that may have been preventable with different design choices. Norman’s language for understanding mistakes is precise. And with this precision, we too can unpack everyday “mistakes” into a systematic way that lets us understand why they happened and how to mitigate or prevent them.
Here lies the power of the book. It’s a grammar book, one that teaches us the language of designers. Armed with the grammar of design, we can start to see the choices of designers and start making some thoughtful design choices ourselves.
A Refreshing New Look
Once you read this book, I’ll warn you. Though you may be armed with a new language, be careful with your criticism when you re-enter the world beyond that comfy armchair and empty coffee cup. Yes, in a way, this new vocabulary feels like a clever way to point a finger at “bad design.” And sure; with these new words and clearly articulated descriptions, we can do that. But let Don Norman do the blaming for you. This book is already riddled with examples of bad design drawing from either history or Norman’s personal experience. Instead, let’s put it to good use. The Design of Everyday Things is an opportunity for us as creators to reflect on how we communicate, how we suggest experiences, to the people who use our creations. So let’s make sure those experiences are good ones.
Side Note: the Revised and Expanded Edition of this book reads very differently from the original edition released way back in 1988. I strongly suggest finding the latest version if you can help it since so many of the examples have been brought up to speed with our times.
Laser cutters are certainly a Hackerspace staple for cutting fabrics in some circles. But for the few fabrics derived from non-woven plastics, why not try fusing them together? That’s exactly what [Dries] did, and with some calibration, the result is a speedy means of seaming together two fabrics–no needles necessary!
The materials used here are non-woven goods often used in disposable PPE like face masks, disposable aprons, and shoe coverings. The common tool used to fuse non-woven fabrics at the seams is an ultrasonic welder. This is not as common in the hackerspace tool room, but laser cutters may be a suitable stand-in.
Getting the machine into a production mode of simply cranking out clothes took some work. Through numerous sample runs, [Dries] found that defocusing the laser to a spot size of 1.5mm at low power settings makes for a perfect threadless seam. The resulting test pockets are quite capable of taking a bit of hand abuse before tearing. Best of all, the fused fabrics can simply be cut out with another pass of the laser cutter. For fixtures, [Dries] started with small tests by stretching the two fabrics tightly over each other but suggests fixtures that can be pressed for larger patterns.
It’s great to see laser-cutters doubled-up as both the “glue” and “scissors” in a textile project. Once we get a handle on lasering our own set of scrubs, why not add some inflatables into the mix?