3D scanning and 3D printing may sound like a natural match for one another, but they don’t always play together as easily and nicely as one would hope. I’ll explain what one can expect by highlighting three use cases the average hacker encounters, and how well they do (or don’t) work. With this, you’ll have a better idea of how 3D scanning can meet your part design and 3D printing needs.
How Well Some Things (Don’t) Work
Most 3D printing enthusiasts sooner or later become interested in whether 3D scanning can make their lives and projects easier. Here are a three different intersections of 3D scanning, 3D printing, and CAD along with a few words on how well each can be expected to work.
Goal
Examples and Details
Does it work?
Use scans to make copies of an object.
3D scan something, then 3D print copies.
Objects might be functional things like fixtures or appliance parts, or artistic objects like sculptures.
Mostly yes, but depends on the object
Make a CAD model from a source object.
The goal is a 1:1 model, for part engineering purposes.
Use 3D scanning instead of creating the object in CAD.
Not Really
Digitize inconvenient or troublesome shapes.
Obtain an accurate model of complex shapes that can’t easily be measured or modeled any other way.
Examples: dashboards, sculptures, large objects, objects that are attached to something else or can’t be easily moved, body parts like heads or faces, and objects with many curves.
Useful to make sure a 3D printed object will fit into or on something else.
Creating a CAD model of a part for engineering purposes is not the goal.
Yes, but it depends
In all of these cases, one wants a 3D model of an object, and that’s exactly what 3D scanning creates, so what’s the problem? The problem is that not all 3D models are alike and useful for the same things.
3D Scanning Makes Meshes, Not CAD Models
Broadly speaking, there are two kinds of 3D models: CAD models, and meshes. These can be thought of as being useful for engineering purposes and artistic purposes, respectively. Some readers may consider that a revolting oversimplification, but it is a helpful one to make a point about how 3D scanning, 3D printing, and CAD work do (and don’t) work together.
Hackers designing parts are typically most interested in CAD models, because these represent real-world objects that get modified in terms of real-world measurements. But 3D scanning will not create a CAD model; it will create a mesh.
Typical CAD model editing example, showing a model as a solid object, altered in terms of geometric features and real-world measurements.
A typical mesh editing operation. The object is a network of points connected into a mesh, which can be manipulated and deformed.
Meshes can be used for engineering purposes — .stl files are meshes after all, and are practically synonymous with 3D printing — but a mesh cannot be modified in the the same ways a CAD file can. With a mesh, one does not extrude a face by a specific number of millimeters, nor does one fillet a corner to a specific radius. Meshes can absolutely be modified, but the tools and processes are different.
To sum up: 3D scanning makes 3D models from real-world objects, but the models that come out of the scanning process aren’t necessarily suitable for engineering purposes without additional work.
Options for the Home-based Hacker
At the beginning of this article I selected three typical intersections of 3D scanning, 3D printing, and CAD work to illustrate the various imperfect fits between them. Now I’ll go into those three use cases in more detail, and provide ways for the average hacker to use 3D scanning to make a project easier.
Using 3D Scanning to Create Copies
Photogrammetry is an accessible way to create 3D models, and free as well as paid options exist. Generally, the smaller and more complex an object, the harder it will be to obtain a result that preserves all the features and details.
Photogrammetry uses multiple photos of an object taken from a variety of different angles, and software interprets these photos to create a point cloud representing the surface of the object. A mesh 3D model representing the object can then be generated. Some cleanup or post-processing of the model is usually required, depending on the method and software.
This blog post from Prusa Research walks through how to get the best results with Meshroom, a free option for 3D scanning using photogrammetry.
OpenScan (and OpenScan Mini) is a DIY project by [Thomas Megel] aimed at using photogrammetry to scan small objects with high accuracy.
RealityCapture is non-free software with a number of useful features and well-made tutorials. Notably, they have a license model option aimed at occasional use and small quantities. Since most software subscription models rarely make sense for hobbyists and one-off projects, it can be worth a look.
Creating a CAD Model from a 3D Scan
Since 3D scanning will not generate a CAD model, it’s not a direct alternative to designing a part in CAD. Most CAD programs allow importing a mesh, but the imported mesh remains a mesh, which cannot be modified in the same way as other CAD objects. It might be useful as a guide for a new design, however.
A mesh converted to a solid will become an object made up of collection of triangular faces, identical to the ones that made up the original mesh. This is rarely what a novice CAD modeler expects.
One may wonder if it is possible to convert from one format to another. It is, but the conversion may not be what one expects. Converting a CAD model into a mesh is simple enough, but converting a mesh into a CAD solid is less straightforward.
If one’s goal is to use 3D scanning to make the creation of a CAD model easier and the conversion result shown here won’t do the trick, the next best thing is to use the 3D scan as a master and model a new part around it to match, using the imported mesh as a guide. One project that uses this approach is this custom trackball designed around a molded ergonomic prototype.
Some professional software suites have the ability to export to CAD, but the essential workflow is the same, with a scanned mesh being used as the reference for a new design.
3D Scanning to Digitize Inconvenient or Troublesome Shapes
This scan of a laser cutter’s panel is obviously only part of the whole machine, but the important part is present.
Sometimes an accurate 3D model of a shape is needed, and that shape isn’t easily modeled or measured by hand. The same photogrammetry tools mentioned earlier are useful here, but their purpose is different. Instead of modeling the object from top to bottom to make an accurate copy, often only part of the object is needed.
For example, modeling the shape of an equipment panel or dashboard requires only the relevant section to be scanned successfully. A person’s head can be scanned to ensure a precise fit for a helmet or mask, and there’s no need to get a full scan of the entire body. In general, fewer pictures are needed and post-processing and model cleanup is easier because there is a smaller area of interest. A size reference must be included somehow for scaling later, because most 3D scans do not intrinsically create 1:1 models.
An excellent example of this approach is this project to design a custom control panel intended to fit an existing piece of equipment. Unlike when scanning a whole object with the intent of duplicating it, there’s no need to capture difficult-to-reach places like the bottom or back. This makes both scanning and model cleanup easier.
Professional Scanning
Another option is to pay for a professional scan. Fancy scanners and software suites costing thousands, or tens of thousands, of dollars and aimed at engineering applications exist, and while they are out of the reach of the average hacker, paying for a company to do a scan or two might not be.
Accuracy and resolution can be beyond what’s possible with photogrammetry, and some of the professional software suites have fancy features like aligning multiple scans, accurate size references, or the ability to generate CAD models based on scan results.
A 1:1 model from a professional 3D scanning tool, the product of aligning and merging multiple separate scans from different angles to get a complete model. It is still a mesh, but it accurately represents the original in both features and scale.
Shown here is the model of a part I had professionally scanned with a Creaform HandySCAN Black 3D scanner, according to my invoice. It is an old wood grip from an antique firearm. The scan still created a mesh, but it was an accurate 1:1 model of the original that I was able to use to print replacements on an SLA 3D printer.
When getting a quote for professional 3D scanning, be sure to ask about fee structure and be clear about your needs. In my case, it was cost-effective to scan multiple similar objects under a single setup fee.
Know What 3D Scanning Can (and Can’t) Do
3D scanning is getting better and more accessible all the time, but the fact that it generates a mesh means it doesn’t always fit smoothly into a 3D printing and CAD part design workflow. That doesn’t mean it can’t be useful, but it does mean that it’s important to know the limitations, and how they will affect your needs.
Of course, one can always dig out the calipers and manually model a part in CAD, but not all parts and shapes are easily measured or reverse-engineered. 3D scanning is a great alternative to modeling complex, real-world objects that would be impractical or error-prone to create by hand.
Have you successfully used 3D scanning to make a project easier, or have a favorite method or tool to share? We definitely want to hear all about it, so please take a moment to share with us in the comments.
Combined with today’s massive flat panel displays, a nice surround sound system can provide an extremely immersive environment for watching movies or gaming. But a stumbling block many run into is speaker placement. The front speakers generally just go on either side of the TV, but finding a spot for the rear speakers that’s both visually and acoustically pleasing can be tricky.
Which is why [Peter Waldraff] decided to take a rather unconventional approach and hide his rear surround sound speakers in a pair of functioning table lamps. This not only looks better than leaving the speakers out, but raises them up off the floor and into a better listening position. The whole thing looks very sleek thanks to some clever wiring, to the point that you’d never suspect they were anything other than ordinary lamps.
The trick here is the wooden box located at the apex of the three copper pipes that make up the body of the lamp. [Peter] mounted rows of LEDs to the sides of the box that can be controlled with a switch on the bottom, which provides light in the absence of a traditional light bulb. The unmodified speaker goes inside the box, and connects to the audio wires that were run up one of the pipes.
In the base, the speaker and power wires are bundled together so it appears to be one cable. Since running the power and audio wires together like this could potentially have resulted in an audible hum, [Peter] only ran 12 VDC up through the lamp to the LEDs and used an external “wall wart” transformer. For convenience, he also put a USB charging port in the center of the base.
Although people-growing is probably a long way off, mice can now mostly develop inside an artificial uterus (try private window if you hit a paywall) thanks to a breakthrough in developmental biology. So far, the mice can only be kept alive halfway through gestation. There’s a point at which the nutrient formula provided to them isn’t enough, and they need a blood supply to continue growing. That’s the next goal. For now, let’s talk about that mechanical womb setup.
Carousel of Care
The mechanical womb was developed to better understand how various factors such as gene mutations, nutrients, and environmental conditions affect murine fetuses in development. Why do miscarriages occur, and why do fertilized eggs fail to implant in the first place? How exactly does an egg explode into 40 trillion cells when things do work out? This see-through uterus ought to reveal a few more of nature’s gestational secrets.
Dr. Jacob Hanna of Israel’s Weizmann Institute spent seven years building the two-part system of incubators, nutrients, and ventilation. Each mouse embryo floats in a glass jar, suspended in a concoction of liquid nutrients. A carousel of jars slowly spins around night and day to keep the embryos from attaching to the sides of the jars and dying. Along with the nutrient fluid, the mice receive a carefully-controlled mixture of oxygen and carbon dioxide from the ventilation machine. Dr. Hanna and his team have grown over 1,000 embryos this way.
Full gestation in mice takes about 20 days. As outlined in the paper published in Nature, Dr. Hanna and team removed mouse embryos at day five of gestation and were able to grow them for six more days in the artificial wombs. When compared with uterus-grown mice on day eleven, their sizes and weights were identical. According to an interview after the paper was published, the team have already gone even further, removing embryos right after fertilization on day zero, and growing them for eleven days inside the mechanical womb. The next step is figuring out how to provide an artificial blood supply, or a more advanced system of nutrients that will let the embryos grow until they become mice.
Embryonic Ethics
Here’s the most interesting part: the team doesn’t necessarily have to disrupt live gestation to get their embryos. New techniques allow embryos to be created from murine connective tissue cells called fibroblasts without needing fertilized eggs. Between this development and Dr. Hanna’s carousel of care, there would no longer be a need to fertilize eggs merely to destroy them later.
It’s easy to say that any and all animal testing is unethical because we can’t exactly get their consent (not that we would necessarily ask for it). At the same time, it’s true that we learn a lot from testing on animals first. Our lust for improved survival is at odds with our general empathy, and survival tends to win out on a long enough timeline. A bunch of people die every year waiting for organ transplants, and scientists are already growing pigs for that express purpose. And unlocking more mysteries of the gestation process make make surrogate pregnancies possible for more animals in the frozen zoo.
In slightly more unnerving news, some have recently created embryos that are part human and part monkey for the same reason. Maybe this is how we get to planet of the apes.
The hack involves popping open the case of the watch and exposing the back of the main PCB. There, a series of jumpers control various features. [Ian]’s theory is that this allows Casio to save on manufacturing costs by sharing one basic PCB between a variety of watches and enabling features via the jumper selection. With a little solder wick, a jumper pad can be disconnected, enabling the hidden countdown feature. Other features, such as the multiple alarms, can be disabled in the same way with other jumpers, suggesting lower-feature models use this same board too.
It’s a useful trick that means [Ian] now always has a countdown timer on his wrist when he needs it. Excuses for over-boiling the eggs will now be much harder to come by, but we’re sure he can deal. Of course, watch hacks don’t have to be electronic – as this custom transparent case for an Apple Watch demonstrates. Video after the break.
Earlier this week, a company Orbital Marine Power successfully launched its latest tidal turbine. Once it’s connected to the European Marine Energy Centre off the Orkney Islands, the two megawatt O2 will have the capacity to generate enough energy to power 2,000 UK households annually, making it one of the world’s most powerful tidal turbines currently in use.
Construction on the project started in 2019. The O2 builds on Orbital’s previous generation SR2000 tidal turbine. The new model consists of a 239-foot superstructure connected to two turbines with 32 foot long rotors. The blades on those can rotate a full 360-degrees. That’s a feature that allows the O2 to generate power from currents without having to move entirely when they change direction. In the future, Orbital says it also has the option to install even larger blades on the O2.
Netherlands politicians (Geert Wilders (PVV), Kati Piri (PvdA), Sjoerd Sjoerdsma (D66), Ruben Brekelmans (VVD), Tunahan Kuzu (Denk), Agnes Mulder (CDA), Tom van der Lee (GroenLinks), Gert-Jan Segers (ChristenUnie) en Raymond de Roon (PVV).) just got a first-hand lesson about the dangers of deepfake videos. According to NL Times and De Volkskrant, the Dutch parliament’s foreign affairs committee was fooled into holding a video call with someone using deepfake tech to impersonate Leonid Volkov (above), Russian opposition leader Alexei Navalny’s chief of staff.
The perpetrator hasn’t been named, but this wouldn’t be the first incident. The same impostor had conversations with Latvian and Ukranian politicians, and approached political figures in Estonia, Lithuania and the UK.
The country’s House of Representatives said in a statement that it was “indignant” about the deepfake chat and was looking into ways it could prevent such incidents going forward.
There doesn’t appear to have been any lasting damage from the bogus video call. However, it does illustrate the potential damage from deepfake chats with politicians. A prankster could embarrass officials, while a state-backed actor could trick governments into making bad policy decisions and ostracizing their allies. Strict screening processes might be necessary to spot deepfakes and ensure that every participant is real.
Russia said it had fined Apple $12 million for alleged [Note: why the use of this word? If the fine has been issued, then a Russian court has established guilt and there is no allleging about it!] abuse of its dominance in the mobile applications market, in the latest dispute between Moscow and a Western technology firm.
The Federal Antimonopoly Service (FAS) said on Tuesday that U.S. tech giant Apple’s distribution of apps through its iOS operating system gave its own products a competitive advantage.
[…]
The FAS said in a statement it had imposed a turnover fine on Apple of 906.3 million roubles ($12.1 million) for the alleged violation of Russian anti-monopoly legislation.
It determined in August 2020 that Apple had abused its dominant position and then issued a directive requiring the U.S. company to remove provisions giving it the right to reject third-party apps from its App Store.
That move followed a complaint from cybersecurity company Kaspersky Lab, which had said that a new version of its Safe Kids application had been declined by Apple’s operating system.
Epic Games is using its lawsuit against Apple to accuse the iPhone maker of being particularly greedy. As The Vergereports, expert witness Eric Barns testified that Apple supposedly had an App Store operating margin of 77.8 percent in 2019, itself a hike from 74.9 percent in 2018. He also rejected Apple witness’ claims that you couldn’t practically calculate profit, pointing to info from the company’s Corporate Financial Planning and Analysis group as evidence.
Apple unsurprisingly disagreed. The tech firm told The Verge the margin calculations are “simply” wrong and that it planned to fight the allegations at trial. The firm’s own witness, Richard Schmalensee, claimed that Barnes was looking at one iOS ecosystem element that distorted the apparent operating margin. The real figure was “unremarkable,” he said, adding that you couldn’t study App Store profit without looking at the broader context of devices and services.
The company doesn’t calculate profits and losses based on products and services, Schmalensee said.
There’s no guarantee the court will accept Barnes’ take. Apple’s overall gross profit margin has typically been high relative to much of the industry, but never that high — it was 42.5 percent during the company’s latest winter quarter. Apple has also tended to portray the App Store as a way to drive hardware sales rather than a money-maker in its own right.
The testimony nonetheless does more to explain how Epic will pursue its case against Apple as the court battle begins on May 3rd. The Fortnite creator not only wants to portray Apple as anti-competitive, but abusing its lock on iOS app distribution to reap massive profits.
Amazon may soon be more accountable for more products than the ones it directly sells. According to the LA Times, a California state appeals court has ruled that Amazon is responsible for the safety of third-party products available through its marketplace following a 2015 hoverboard fire. While the internet giant argued that it was only connecting buyers with sellers, judges determined that there was a “direct link” in distribution that made the company liable.
The company won the initial ruling. At the time, a judge sided with Amazon’s view that it was just advertising sellers’ products rather than participating in sales.
In a statement to the Times, Amazon said it “invests heavily” in product safety by screening sellers and products. it also keeps watch on the store for hints of problems. The company declined to comment on the appeal court decision, including whether it intended to challenge the ruling at the state Supreme Court.
The decision, if it holds, could force Amazon to change policies. The tech giant may have to step up its vetting process for sellers and be ready to accept liability for safety problems, including lawsuits. Other stores with similar third-party marketplaces would have to follow suit. That, in turn, might be good news for shoppers —you could see fewer sketchy products in online stores, and you’d have a better chance of resolving safety issues.
Researchers from University of Arizona and University of Utah published a new paper in the Journal of Marketing that examines why most scholarly research is misinterpreted by the public or never escapes the ivory tower and suggests that such research gets lost in abstract, technical, and passive prose.
The study, forthcoming in the Journal of Marketing, is titled “Marketing Ideas: How to Write Research Articles that Readers Understand and Cite” and is authored by Nooshin L. Warren, Matthew Farmer, Tiany Gu, and Caleb Warren.
From developing vaccines to nudging people to eat less, scholars conduct research that could change the world, but most of their ideas either are misinterpreted by the public or never escape the ivory tower.
Why does most academic research fail to make an impact? The reason is that many ideas in scholarly research get lost in an attic of abstract, technical, and passive prose. Instead of describing “spilled coffee” and “one-star Yelp reviews,” scholars discuss “expectation-disconfirmation” and “post-purchase behavior.” Instead of writing “policies that let firms do what they want have increased the gap between the rich and the poor,” scholars write sentences like, “The rationalization of free-market capitalism has been resultant in the exacerbation of inequality.” Instead of stating, “We studied how liberal and conservative consumers respond when brands post polarizing messages on social media,” they write, “The interactive effects of ideological orientation and corporate sociopolitical activism on owned media engagement were studied.”
Why is writing like this unclear? Because it is too abstract, technical, and passive. Scholars need abstraction to describe theory. Thus, they write about “sociopolitical activism” rather than Starbucks posting a “Black Lives Matter” meme on Facebook. They are familiar with technical terms, such as “ideological orientation,” and they rely on them rather than using more colloquial terms such as “liberal or conservative.” Scholars also want to sound objective, which lulls them into the passive voice (e.g., the effects… were studied) rather than active writing (e.g., “we studied the effects…”). Scholars need to use some abstract, technical, and passive writing. The problem is that they tend to overuse these practices without realizing it.
When writing is abstract, technical, and passive, readers struggle to understand it. In one of the researchers’ experiments, they asked 255 marketing professors to read the first page of research papers published in the Journal of Marketing (JM), Journal of MarketingResearch (JMR), and Journal of Consumer Research (JCR). The professors understood less of the papers that used more abstract, technical, and passive writing compared to those that relied on concrete, non-technical, and active writing.
As Warren explains, “When readers do not understand an article, they are unlikely to read it, much less absorb it and be influenced by its ideas. We saw this when we analyzed the text of 1640 articles published in JM, JMR, and JCR between 2000 and 2010. We discovered that articles that relied more on abstract, technical, and passive writing accumulated fewer citations on both Google Scholar and the Web of Science.” An otherwise average JM article that scored one standard deviation lower (clearer) on our measures of abstract, technical, and passive writing accumulated approximately 157 more Google Scholar citations as of May 2020 than a JM article with average writing.
Why do scholars write unclearly? There is an unlikely culprit: knowledge. Conducting good research requires authors to know a lot about their work. It takes years to create research that meaningfully advances scientific knowledge. Consequently, academic articles are written by authors who are intimately familiar with their topics, methods, and results. Authors, however, often forget or simply do not realize that potential readers (e.g., Ph.D. students, scholars in other sub-disciplines, practicing professionals, etc.) are less familiar with the intricacies of the research, a phenomenon called the curse of knowledge.
The research team explores whether the curse of knowledge might be enabling unclear writing by asking Ph.D. students to write about two research projects. The students wrote about one project on which they were the lead researcher and another project led by one of their colleagues. The students reported that they were more familiar with their own research than their colleague’s research. They also thought that they wrote more clearly about their own research, but they were mistaken. In fact, the students used more abstraction, technical language, and passive voice when they wrote about their own research than when they wrote about their colleague’s research.
“To make a greater impact, scholars need to overcome the curse of knowledge so they can package their ideas with concrete, technical, and active writing. Clear writing gives ideas the wings needed to escape the attics, towers, and increasingly narrow halls of their academic niches so that they can reduce infection, curb obesity, or otherwise make the world a better place,” says Farmer.
