From bespoke seats to titanium arms, 3D printing is helping Paralympians gain an edge

Jeff Crow/AAP Image

Authors: James Novak, The University of Queensland | Andrew Novak, The University of Technology Sydney

** Please note: this is a copy of an article I wrote for The Conversation, published on 3rd September, 2021, and is shared under a CC-BY-ND license. You can access the original article by clicking here.**

Major sporting events like the Paralympics are a breeding ground for technological innovation. Athletes, coaches, designers, engineers and sports scientists are constantly looking for the next improvement that will give them the edge. Over the past decade, 3D printing has become a tool to drive improvements in sports like running and cycling, and is increasingly used by paralympic athletes.

The Paralympics features athletes with a diverse range of abilities, competing in a wide range of different categories. Many competitors use prosthetics, wheelchairs or other specialised components to enable them to perform at their best.

One interesting question is whether 3D printing widens or narrows the divide between athletes with access to specialised technologies, and those without. To put it another way, does the widespread availability of 3D printers — which can now be found in many homes, schools, universities and makerspaces — help to level the playing field?

Forget mass production

Mass-manufactured equipment, such as gloves, shoes and bicycles, is generally designed to suit typical able-bodied body shapes and playing styles. As such, it may not be suitable for many paralympians. But one-off, bespoke equipment is expensive and time-consuming to produce. This can limit access for some athletes, or require them to come up with their own “do-it-yourself” solutions, which may not be as advanced as professionally produced equipment.

3D printing can deliver bespoke equipment at a more affordable price. Several former paralympians, such as British triathlete Joe Townsend and US track athlete Arielle Rausin, now use 3D printing to create personalised gloves for themselves and their fellow wheelchair athletes. These gloves fit as if they were moulded over the athlete’s hands, and can be printed in different materials for different conditions. For example, Townsend uses stiff materials for maximum performance in competition, and softer gloves for training that are comfortable and less likely to cause injury.

3D-printed gloves are inexpensive, rapidly produced, and can be reprinted whenever they break. Because the design is digital, just like a photo or video, it can be modified based on the athlete’s feedback, or even sent to the nearest 3D printer when parts are urgently needed.


Read more: Paralympians still don’t get the kind of media attention they deserve as elite athletes


Harder, better, faster, stronger

An elite athlete might be concerned about whether 3D-printed parts will be strong enough to withstand the required performance demands. Fortunately, materials for 3D printing have come a long way, with many 3D printing companies developing their own formulas to suit applications in various industries – from medical to aerospace.

Back in 2016, we saw the first 3D-printed prosthetic leg used in the Paralympics by German track cyclist Denise Schindler. Made of polycarbonate, it was lighter than her previous carbon-fibre prosthetic, but just as strong and better-fitting.

With research showing sprint cyclists can generate more than 1,000 Newtons of force during acceleration (the same force you would feel if a 100-kilogram person were to stand on top of you!), such prosthetics need to be incredibly strong and durable. Schindler’s helped her win a bronze medal at the Tokyo games.

Denise Schindler on her way to a medal in Tokyo. Thomas Lovelock

More advanced materials being 3D printed for Paralympic equipment include carbon fibre, with Townsend using it to produce the perfect crank arms for his handbike. 3D printing allows reinforced carbon fibre to be placed exactly where it is needed to improve the stiffness of a part, while remaining lightweight. This results in a better-performing part than one made from aluminium.

3D-printed titanium is also being used for custom prosthetic arms, such as those that allow New Zealand paralympian Anna Grimaldi to securely grip 50kg weights, in a way a standard prosthetic couldn’t achieve.

Different technologies working together

For 3D printing to deliver maximum results, it needs to be used in conjunction with other technologies. For example, 3D scanning is often an important part of the design process, using a collection of photographs, or dedicated 3D scanners, to digitise part of an athlete’s body.

Such technology has been used to 3D-scan a seat mould for Australian wheelchair tennis champion Dylan Alcott, allowing engineers to manufacture a seat that gives him maximum comfort, stability and performance.

3D scanning was also used to create the perfect-fitting grip for Australian archer Taymon Kenton-Smith, who was born with a partial left hand. The grip was then 3D-printed in both hard and soft materials at the Australian Institute of Sport, providing a more reliable bow grip with shock-absorbing abilities. If the grip breaks, an identical one can be easily reprinted, rather than relying on someone to hand-craft a new one that might have slight variations and take a long time to produce.


Read more: 3 reasons why Paralympic powerlifters shift seemingly impossible weights


All these technologies are increasingly accessible, meaning more non-elite athletes can experiment with unique parts. Amateurs and professionals alike can already buy running shoes with 3D-printed soles, and 3D-printed custom bike frames. For those with access to their own 3D printer, surf finscycling accessories and more can be downloaded for free and printed for just a few dollars.

However, don’t expect your home 3D printer to be making titanium parts anytime soon. While the technology is levelling the playing field to a certain extent, elite athletes still have access to specialised materials and engineering expertise, giving them the technological edge.


This article was co-authored by Julian Chua, a sports technology consultant at ReEngineering Labs and author of the Sports Technology Blog.

3D Printing Build Farms

3D printing is a slooooow process. While 3D printing geeks like me can spend hours watching a printer lay down layers of plastic, it often turns manufacturers off who are used to rapid manufacturing process like injection moulding where parts can be pumped out every few seconds. However, there is a way to produce products en masse and it’s called the 3D printing build farm.

Perhaps you’ve already seen images like the ones above – these are well known examples of 3D printing build farms at Ultimaker (left) and Prusa (right) that illustrate what they’re all about: Lots and lots of 3D printers! A 3D printing build farm is basically just a collection of several 3D printers, or many hundreds of 3D printers, that can significantly scale up the production of parts. These can often be networked together as part of a single management system, meaning only a small number of workers are needed to keep an eye on things. The benefit over other mass production technologies is that you still retain the benefits of 3D printing a unique item on every 3D printer, rather than just producing thousands of exactly the same product. Of course, you can also produce thousands of the same part, for example the Prusa build farm is made up of over 500 of their own 3D printers, which are used to print many of the parts to assemble new 3D printers.

A centralised build farm (left) and a decentralised, geographically dispersed build farm (right)

Recently I published a book chapter analysing 3D printing build farms in the context of work and the future. Titled ‘3D Printing Build Farms: The Rise of a Distributed Manufacturing Workforce,’ one of the main opportunities we discuss that has not yet been exploited is for 3D printing build farms to be geographically distributed, rather than centralised within a single facility (illustrated above). If all the 3D printers within the build farm are connected to a central management system, then they do not actually need to be located in the same physical location.

Obviously there are some benefits to having all the machines located together, particularly for maintenance and monitoring. However, there may also be several benefits to distributing the 3D printers domestically or internationally, particularly in light of the COVID-19 pandemic and the longer-term changes we may now enjoy working from home, or at least working in a more decentralised manner:

  • 3D printers can be located closer to customers. Centralised 3D printing build farms must still ship products around the world, just like conventional manufacturers, which costs time and money.
  • Distributed farms may better suit new flexible working conditions, allowing people to work the hours they want, from a location they want.
  • New jobs in regional areas with smart regions connected to smart cities. 3D printers may be distributed in regional areas, as well as cities, reducing the need for people to relocate to overcrowded cities in order to find work.
  • Businesses may join forces and utilise shared “nodes” of the 3D printing build farm.

Time will tell if this provides businesses with new advantages, but it is clear that build farms, whether centralised or distributed, are a growing trend with real commercial value. Some of the biggest adopters are in the dental industry, for example SmileDirectClub which uses 49 multi jet fusion 3D printers from HP to manufacture moulds for up to 49,000 clear aligners each day. This is big business, driven by 3D printing and build farm systems.

– Posted by James Novak

3D Printing in Sport – Hit or Hype?

If you’re into 3D printing, no doubt you are familiar with some of the ways it is being used in sports. Some of my own products (above) have included a 3D printed bicycle frame, smart bicycle helmet and surf fins, while in the media products have included shoes, golf clubs and shin pads.

However, as a researcher, I was interested to know how this translates into academic research. How many research studies have been looking at 3D printing for sports products? How much improvement does a 3D printed product offer over a conventional one? Which sports are adopting 3D printing? Working with my brother, Dr Andrew Novak, we hypothesized that given the amount of coverage in 3D printing media, there should be quite a large amount of research supporting the developments of iconic 3D printed sports products, as well as novel developments that haven’t even made it into the media yet. The results – published in a paper titled ‘Is additive manufacturing improving performance in Sports? A systematic review‘ – were surprising (preprint version freely available).

Up until May 2019, we found only 26 academic studies that provided any empirical evidence related to 3D printing for sports products. The graph above shows which sports, and how many articles have been published. The first of these appeared in 2010. Running/walking was the most popular sport with 10 articles (38%), followed by cycling with 4 articles (15%) and badminton with 3 articles (12%). All other sports – baseball, climbing, cricket, football (soccer), golf, hurling, in-line skating, rowing and surfing – had only been assessed in single studies. This means that a lot of research into 3D printing of sports products are just one-off projects, and indicates that there may be very little funding/interest to continue building larger projects.

It also suggests that any research being done to support mainstream commercial applications of 3D printing, for example for brands like Adidas and Specialized, is protected by intellectual property (IP) and not being published.

10 articles (38%) observed improvements in performance of products developed via 3D printing compared to conventionally manufactured products, 8 articles (31%) found a similar performance, and 5 articles (19%) found a lower performance.

From a technical perspective, powder bed fusion technologies were the most utilized with 50% of articles using either selective laser sintering (SLS) or selective laser melting (SLM), although 52% of articles did not name the 3D printer used and 36% did not name any software used to design or optimize products. 3D scanning technology was also utilized in 11 articles (42%).

So, is 3D printing in sport a hit or hype? Based on this research it is clear that within academia, 3D printing is still in the very early phases of consideration, and seems to be significantly behind industry. While you may be able to go and buy some 3D printed running shoes or insoles, or cycle on a 3D printed saddle, you won’t find any objective data in journal articles on these products or much research to suggest that 3D printed products are any better than conventionally manufacture products.

– Posted by James Novak

Popular 3D Prints on Thingiverse

Anyone with a 3D printer will no doubt be familiar with Thingiverse, an online database of files that can be searched, downloaded and 3D printed; a universe of things. I’ve been using it for 7 years, and you can find many of my projects from this blog available there.

While the platform isn’t without its issues, particularly over the last year or so, it is still the largest 3D printing file database with over 1.9 million files at this time of writing – you couldn’t print that much stuff in a lifetime!

Because of the scale, many researchers have used Thingiverse as a way of understanding how people engage with 3D printing and file sharing, and beginning in 2018, I wanted to understand the characteristics of the most popular files on Thingiverse. My research paper has just been published called “500 days of Thingiverse: a longitudinal study of 30 popular things for 3D printing” and as the name suggests, involved tracking 30 things over a 500 day period.

The image at the top is one of the graphs from the paper that compares the downloads per day for these 30 things over time. At the start of the study, a new design called the Xbox One controller mini wheel had just been released and was all over social media, attracting a lot of attention and downloads. This equated to 698 downloads per day. However, this momentum didn’t last. In comparison, well established designs like #3DBenchy continued to increase in downloads per day, and during the period of this study, #3DBenchy became the first thing on Thingiverse to be downloaded over 1 million times! These numbers are beginning to approach figures on more mainstream social media and image/video sites, showing just how popular 3D printing has become. And keep in mind, this is just one of many file sharing websites for 3D printing, a topic that was part of a previous research paper I wrote with friend, colleague and fellow maker, Paul Bardini.

If you’re interested in all the details, I have shared a preprint version of the paper which can be freely accessed. Additionally, all of the raw data can be freely accessed if you’re interested in diving into the nitty gritty details, or even continuing to add to what I started. I hope this provides some insights into the scale of making and 3D printing, and some of the trends that drive the most popular files on Thingiverse.

– Posted by James Novak

3D Printed Face Shields vs. Masks

As the graphic above shows, 3D printing a face shield is twice as fast as 3D printing a face mask. How do I know?

In my latest journal article called A quantitative analysis of 3D printed face shields and masks during COVID-19, I documented 37 face shields and 31 face masks suitable for fused filament fabrication (FFF, or FDM). The graphic provides the average data for all the different designs, including a range of qualities including the amount of filament required, number of 3D printed parts, total volume of all parts, and the dimensions of the largest part for each design (so you know if it will fit within your 3D printer’s build volume). If you’re interested in all of the specific details for each of the individual designs, all of the data is free to access here. You might also want to start with my first article analysing 91 3D printing projects at the start of the pandemic.

Why is this important? Well, if you look at the graph above, you can see that the print time and amount of filament for each individual design varies significantly. For face shields, the shortest print time was 46mins to produce a single part with 12g of material for the Version 1 face shield from MSD Robotics Lab. The longest print time for a face shield was 4h 34min (274min) and required 63g of filament, also only a single part from MITRE Corporation. This means that for each MITRE Corporation face shield you could 3D print almost 6 MSD Robotics Lab face shields. This is a big difference if you’re trying to maximise the quantity you produce for your local hospital or health centre. Below you can visually see how different they are, and why there is such a difference in print time and filament use.

Print times vary even more for face masks, with the shortest print time being 2h 14min (134mins) requiring 32g of filament for a 3-part design from Collective Shield (v.0.354). This design is 3D printed in a flat form only 0.6mm thick and then folded into a 3D face mask, often referred to as a “2.5D print.” In contrast, the longest print time for a face mask was 10h 32mins (632mins) with 130g of filament required to print 26 separate parts, forming a respirator style mask called Respirator V2 from Maker Mask. Both of these different designs can be seen below.

Assuming a price for PETG filament of $30/Kg, the cost of 3D printed components for face shields can be calculated to range from $0.33–1.95, while the range of face masks was $0.96–3.90. For one-off products these differences may not be critical to makers, yet when multiplied by hundreds of thousands or even millions (e.g. the IC3D Budmen face shield has been 3D printed over 3 million times!), the potential investment by makers, organisations, charities and businesses may vary significantly based on the selection of one design over another, or one version of a design over another.

If you want to find more of the data and read the detailed analysis, please read the full article here. I look forward to continuing to bring you new analysis of 3D printing during COVID-19.

– Posted by James Novak

3D Printing and COVID-19 in Data

Figure 2 Timeline

Following my previous post discussing some of the opportunities and challenges of using 3D printing to fill supply chain holes during COVID-19, I’m pleased to share the more detailed research I’ve been working on that supported my article in The Conversation.

Published here in an open access journal is an analysis of all 3D printing projects that were initiated during the first months of the pandemic. As a summary, the image above shows the timeline of these projects, and the types of products that were being produced. In total, 91 projects were documented in my research, with only 7 of these occurring before the World Health Organization (WHO) declaration of a pandemic on March 11. Most of these were based in Asia. The remaining 84 projects (92%) followed the declaration as the pandemic spread around the world and health systems rapidly struggled to meet the demand.

The figure above also shows that 60% of projects were for personal protective equipment (PPE) such as face shields and goggles, while 20% were for ventilator components, and a further 20% were for miscellaneous projects such as hands-free door openers.

200523 3D Print COVID-19 Data

Of the PPE projects, 62% were for face shields as shown above in the left chart. This includes the popular Prusa RC3 face shield pictured in my previous post, although the first documented face shield actually occurred on February 25 from The Hong Kong Polytechnic University. Obviously face shields are a relatively low risk product compared to components for a ventilators, and makers could easily 3D print these on desktop 3D printers.

The chart on the right above documents the types of 3D printing technologies used for each of the 91 projects. Perhaps it is no surprise that fused filament fabrication (FFF) was the most used, accounting for 62% of projects. Resin printing with stereolithography (SLA) or digital light processing (DLP) was the next most popular for 10% of projects, followed by multi jet fusion (MJF=9%), selective laser sintering (SLS=8%), continuous liquid interface production (CLIP=2%), and concrete was used in one project in China to 3D print concrete isolation houses for Xianning Central Hospital in Hubei. Interestingly, 8% of projects did not specify the 3D printing technology being utilised, suggesting that some projects lacked documentation or were reported by the media simply as “3D printing.”

While this review provides an overview of the broad trends related to the 3D printing of health and medical products during the first months of the COVID-19 pandemic, ongoing research is needed to continue monitoring 3D printed products throughout the pandemic to understand longitudinal trends. For example, does the initial hype from March subside and a more stable pattern of research and collaboration continue through April and the following months? Do projects consolidate and merge, with others ending as regulations tighten, or traditional supply chains stabilise?

It will also be necessary to analyse 3D printed products and validate them, particularly as the health crisis continues for months or even years. Initial 3D printing projects, while well intentioned, were largely unregulated and a reflexive response to direct and immediate needs. As supplies stabilise, and the infection curve flattens, more time and resources can be devoted to research, building upon the NIH 3D Print Exchange database of approved designs, perhaps developing an approved FDA or TGA database of designs as well as 3D print technologies and materials. These may be necessary for any future outbreaks of the virus, as well as allowing for better preparation for future health, humanitarian and natural disaster crises that may require a similarly rapid response to equipment shortages.

If you want to find more of the data and read the detailed analysis, please read the article here. Additionally, you can freely access all of the data I collected for this research, and continue building off it, by accessing it on Figshare. I hope it is useful for building our understanding of how 3D printing can be deployed during a health crisis.

– Posted by James Novak

Millions of products have been 3D printed for the coronavirus pandemic – but they bring risks

Header Image High Res

** Please note: this is a copy of an article I wrote for The Conversation, published on 5th May, 2020, and is shared under a CC-BY-ND license. You can access the original article by clicking here.**

With the COVID-19 pandemic, an urgent need has risen worldwide for specialised health and medical products. In a scramble to meet demand, “makers” in Australia and internationally have turned to 3D printing to address shortfalls.

These days 3D printers aren’t uncommon. In 2016, an estimated 3% of Australian households owned one – not to mention those available in schools, universities, libraries, community makerspaces and businesses.

3DEC Lab

A collection of desktop 3D printers in the Deakin University 3DEC lab. James Novak

Across Europe and the United States, access to essential personal protective equipment (PPE) remains a concern, with nearly half of all doctors in the UK reportedly forced to source their own PPE.

In Australia, reports from March and early April showed hospital staff reusing PPE, and health-care workers sourcing PPE at hardware stores due to shortages.

The global supply chain for these vital products has been disrupted by widespread lockdowns and reduced travel. Now, 3D printing is proving more nimble and adaptable manufacturing methods. Unfortunately, it’s also less suited for producing large numbers of items, and there are unanswered questions about safety and quality control.

Sharing is caring

One of the earliest examples of 3D printing being used for pandemic-related purposes is from mid-February. One Chinese manufacturer made 3D-printed protective goggles for medics in Wuhan. With 50 3D printers working around the clock, they were producing about 300 pairs daily.

Designers, engineers, students, manufacturers, doctors and charities have used 3D printing to produce a variety of products including face shields, masks, ventilator components, hands-free door openers and nasal swabs.

Many designs are freely shared online through platforms such as the NIH 3D Print Exchange. This US-based 3D printing community recently partnered with the Food and Drug Administration (FDA) and the Department of Veterans Affairs, to assist with validating designs uploaded by the community. So far, 18 3D-printable products have been approved for clinical use (although this is not the same as FDA approval).

Such online platforms allow makers around the world not only to print products based on uploaded designs, but also to propose improvements and share them with others.

Just because you can, doesn’t mean you should

In a public health crisis of COVID-19’s magnitude, you may think having any PPE or medical equipment is better than none.

However, Australia’s Therapeutic Goods Administration (TGA) – our regulatory body for medical products – has not yet endorsed specific 3D-printed products for emergency use during COVID-19. Applications for this can be made by manufacturers registered with the TGA.

However, the TGA is providing guidelines which designers, engineers and manufacturers are working with. For example, Australian group COVID SOS aims to respond to direct requests by frontline medical workers for equipment they or their hospital need. So, local designers and manufacturers are directly connected to those in need.

3D printing provides a means to manufacture unique and specialised products on demand, in a process known as “distributed manufacturing”.

Unfortunately, compared with mass production methods, 3D printing is extremely slow. Certain types of 3D-printed face shields and masks take more than an hour to print on a standard desktop 3D printer. In comparison, the process of “injection moudling” in factory mass production takes mere seconds.

That said, 3D printing is flexible. Makers can print depending on what’s needed in their community. It also allows designers to improve over time and products can get better with each update. The popular Prusa face shield developed in the Czech Republic has already been 3D printed more than 100,000 times. It’s now on its third iteration, which is twice as fast to print as the previous version.

Prusa RC3 Face Shield

A Prusa RC3 face shield 3D printed on a desktop 3D printer. James Novak

Opportunity vs risk

But despite the good intent behind most 3D printing, there are complications.

Do these opportunities outweigh the risks of unregulated, untested product used for critical health care situations? For instance, if the SARS-CoV-2 virus can survive two to three days on plastic surfaces, it’s theoretically possible for an infected maker to transfer the virus to someone else via a 3D-printed product.

Medical products must be sterilised, but who will ensure this is done if traditional supply chains are bypassed? Also, some of the common materials makers use to 3D print, such as PLA, aren’t durable enough to withstand the high heat and chemicals used for sterilisation.

And if 3D-printed products are donated to hospitals in large batches, identifying and treating different materials accordingly would be challenging.

For my research, I’ve been tracking 3D-printed products produced for the pandemic. In a soon-to-be-published study, I identify 34 different designs for face shields shared online prior to April 1. So, how do medical practitioners know which design to trust?

If a patient or worker is injured while wearing one, or becomes infected with COVID-19, who is responsible? The original designer? The person who printed the product? The website hosting the design?

These complex issues will likely take years to resolve with health regulators. And with this comes a chance for Australia – as a figurehead in 3D printing education – to lead the creation of validated, open source databases for emergency 3D printing.

– Posted by James Novak

Read more: Can 3D printing rebuild manufacturing in Australia?

Fingerprint Stool 3D Printed on a BigRep ONE

Fingerprint Stool BigRep ONE

Size matters!

I’ve been throwing out teasers about this project on social media for over a year, and with my research just published in the Rapid Prototyping Journal, it is very exciting to finally be at the finish line and able to share it – all of it! So what exactly is it?

Well, it’s a 3D printed stool. But more than that, it’s the outcome of a design for additive manufacturing case study using the new BigRep ONE 3D printers, housed in the ProtoSpace facility at the University of Technology Sydney. The BigRep ONE is essentially a desktop FDM 3D printer on steroids, with a build volume measuring 1005 x 1005 x 1005mm, that’s over 1 cubic meter of space to 3D print! And much like a desktop FDM printer it uses filaments like PLA, PETG, TPU and realistically just about any other filament material, as well as using a Simplify3D profile for slicing, so designing for the printer and operating it is identical to many common desktop 3D printers.

edfGiven the newness of these machines when they were installed in ProtoSpace in early 2018, my job was to test the capabilities of them whilst developing a showcase product to highlight how they can be used to develop new types of products, and with such a large build volume, furniture was an obvious choice. However, my budget was not unlimited ($1500 AUD) and nor was the time I was allowed to run the printer, which was capped at 5 days so that it was not taken out of commission for other users for more than one working week. Sounds like a generous timeframe unless you’re familiar with just how slow FDM printing is even at the desktop scale, and while this printer is bigger, it is certainly not any faster. And when you are printing for 5 days, this machine will really chew through filament, so that $1500 budget quickly runs out.

In terms of the fingerprint concept, the stool was designed when I was newly engaged and uses a fingerprint from my (now wife’s) ring finger, and my own. Awwwwe… There are few features more unique to each human than a fingerprint, so this concept was also chosen as a truly unique feature that highlights the capacity for 3D printing to be used for one-off personalised products.

The above video helps explain the design and printing process, which essentially involved:

  1. Ink used to take impressions of fingerprints on paper.
  2. Fingerprints digitised using a flatbed scanner.
  3. Fingerprints vectorised in Adobe Illustrator. Exported as DXF files.
  4. DXF files imported into Solidworks CAD software and oriented 420mm apart for the height of the stool.
  5. Manual creation of the 3D geometry.
  6. Export to STL.
  7. Slice in Simplify3D.
  8. 3D print on the BigRep ONE [1mm nozzle diameter, 0.5mm layer height, 5% infill, 2 walls, 3000mm/min print speed]

Sounds nice and straight forward. However, I must admit things did not go this smoothly: Firstly, designing to fit a specific budget and print time required several iterations, with an early version of the design twice as large as the design pictured here. This meant initial cost estimates were in the range of $2194-3882 and print times 117.5-216.1hours – talk about variation! All of this variation is due to experimenting with process parameters like layer height and nozzle diameter for the same design, and was an important learning process that could be taken back into later iterations of the design, which ultimately became smaller.

Fingerprint Stool BigRep Adhesion

Secondly, another obstacle we struggled with was bed adhesion. This is a common problem with desktop machines, however, not normally when printing with PLA. We quickly found that during the first layers, a slight warp or piece of material sticking up would get knocked by the extruder, causing a knock-on effect as the extruder and any material it had collected quickly cause all of the individual sections of the fingerprint to dislodge. Pictured above on the left is the largest section that printed before some material snapped off and somehow caused the nozzle to become entombed in PLA, pictured above on the right. That was an expensive error, new nozzles for the BigRep ONE do not come cheap!

Given the design was intended to print without any need for support material, we eventually had to concede defeat and add a raft. This had the effect of linking all of the initially individual sections of fingerprint together during the first layers, and provided a strong adhesion to the bed. While we could’ve tried all sorts of glues, tapes and other hacks, we didn’t want to resort to these on such a new machine until we had more time to test settings and work with BigRep on a solution. The good news: the raft worked and after 113 hours, and at a cost of $1634 (only slightly over budget), the Fingerprint Stool was complete. The raft did take 1 hour to remove with a hammer and chisel (with a 1mm nozzle there is so much material it cannot be removed by hand), and the surface finish is quite rough – but in my mind this is the charm of FDM, just like a piece of timber has grain and knots that are simply part of the material.

Overall the BigRep ONE is an exciting technology, you just need to keep in mind that due to the scale, all of the small issues you can experience on a cheap desktop machine are also magnified. However, it is great for producing large-scale functional parts like furniture, or any of the other examples you may have seen from BigRep in 3D printing news over recent months.

This is a brief overview of the project, there is much more technical information and analysis in my paper in the Rapid Prototyping Journal, including metrology data of the final design compared with the 3D file, as well as surface roughness data. I’d love to hear your feedback on the project or your own experiences with the printer if you’ve been lucky enough to use one. And keep an eye out for updates about the stool appearing in an exhibition later in the year 😉

UPDATE: Thank you to BigRep for taking an interest in this project and writing their own story about it here, and to 3D Printing Industry for also sharing this story.

– Posted by James Novak

3D printing is cool, but have you tried 2.5D printing?

20190617 2-5D Print Thin Wall 3D

Over the last 18 months or so I’ve been stripping back FDM 3D printing to its basics, experimenting with a variety of materials, composites and patterns designed to be printed flat and assembled into more complex 3D forms. Why?

Well there are many reasons why you might want to use a 3D printer to create relatively flat forms: firstly, as anyone who has used a 3D printer would know, the process is extremely slow. The less vertical height you need to print the faster your part will be completed (generally). Secondly, most accessible 3D printers have a very small build volume, and often you want to 3D print something huge. By 3D printing a lot of smaller, flat parts and assembling them later, you can create a large 3D printed object on a small machine (for example check out the full length inBloom Dress by XYZ Workshop which was assembled out of 191 smaller panels).

This type of 3D printing has actually been called 2.5D printing, since it is essentially the production of 2D geometry that is extruded in a single direction. No fancy lattice structures or compound curves here! Below are some examples I’ve printed over the years, and while some of them like the mesostructure (centre) may look complex, the geometry can be described by a single 2D drawing and extrusion (Z) dimension.

20190617 2-5D Print Examples

What I’ve learned is that when you are 2.5D printing often thin geometries, optimising the dimensions of the geometry for the specific capabilities of your FDM machine are critical. In fact, just a 0.1mm change in the thickness of a wall can reduce your print time by ~50%, which is a huge time saving. Knowing what these “magic” wall thickness settings are is powerful, and also very simple when you understand the logic.

This information has now been published in a book chapter titled “Designing Thin 2.5D Parts Optimized for Fused Deposition Modeling,” and provides several equations you can use to quickly calculate the optimum dimensions you should use if you want to 2.5D print (or even 3D print) as quickly as possible with maximum accuracy. Below is a visual graph that can be used to select the optimum wall thickness settings when 3D printing with a 0.4mm nozzle, and also shows the effect STL resolution can have. Full details about this graph can be found in the book, however the short version is that you want to be designing thin wall features using dimensions that fall inside the black boxed (or dashed) regions. So, for example if you will be using a 0.8mm printed wall thickness (representing 2×0.4mm extrusions in your slicer), the optimum dimensions to design with in CAD are 0.5-0.8mm, 1.3-1.6mm, or 2.0-2.3mm. Anything outside of these dimensions will require some level of infill structure which takes longer to print, and can result in a more messy part.

20190617 3D Print Thin Wall

For a part similar to the mesostructure earlier, we calculated that simply adding 0.1mm of thickness to the design from 1.2mmm up to 1.3mm would decrease print time by 38% – yes, it sounds counter-intuitive, but adding material can actually reduce print time!

Designing for additive manufacturing (DfAM) is a very important research area, and it is knowledge like this that I hope can be implemented by designers, manufacturers and others involved in 3D printing. If you want to learn more about 2.5D printing, and the equations you can use to calculate the “optimized zones” for your own 3D printer, please check out my chapter which can be purchased with a 40% discount using my author code “IGI40,” or if you are at a university you may find you already have access through your library subscriptions.

Happy 2.5D printing.

– Posted by James Novak

3D Printing Pop Culture & Viral Objects

20190508 Pop Culture 3D Print

As regular readers of this blog will know, I’ve been involved with 3D printing, making, education and various online communities for a while now. Which is why it’s very exciting to share my latest piece of writing, a book chapter titled “The Popular Culture of 3D Printing: When the Digital Gets Physical” which I wrote with former colleague and fellow maker Paul Bardini from Griffith University.

As the name suggests, the chapter looks at the popular cultural context of 3D printing, rather than the more technical aspects featured in most academic writing. As makers, we are both really interested in the growth of 3D printing and spread of 3D printing files on platforms like Thingiverse, MyMiniFactory and others, so we got a bit scientific and collected some data. The results are very interesting!

Print

Firstly, one of the things we did was collect the total number of files available from a range of 3D printing file repositories, as well as other more general 3D file repositories. Above is the data we collected (on 26th August 2018) which clearly shows Thingiverse to be the largest specific 3D printing file website. This is no surprise given that the website began in 2008, well before most competitors, building a network effect that still seems to be going strong despite some of the most recent challenges Thingiverse has been experiencing. However, there are plenty of other much larger libraries of CAD files that could be searched for 3D printing files, and even though some will be specific to certain CAD software, there’s always a way to make these 3D printable.

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Given the size of Thingiverse, we then looked at the most popular designs on the platform, collecting data (you will have to check out the full chapter for this!), and then calculated the average downloads per day for these designs. The graph above shows this data against the date the design was uploaded to the platform. Some of the names you may recognise: #3DBenchy, Baby Groot, the XYZ 20mm Calibration Cube and the Xbox One controller mini wheel. But what does it all mean?

Well, the short story is that objects uploaded to Thingiverse today will be downloaded in higher volumes per day than objects uploaded earlier in Thingiverse’s history. The trend line is increasing, matching the growth of 3D printer ownership; more people are downloading more things, with the Xbox One controller mini wheel recording 700 downloads per day when it was newly released. However, #3DBenchy is by far the most downloaded design of all time, right now having been downloaded over 900,000 times on Thingiverse alone, as well as being available on almost every other 3D file platform. This has lead to our classification of it as a “viral object.” Similar to viral videos and viral media campaigns, a viral object extends these concepts into the physical world through 3D printing, being first spread rapidly through online file sharing communities, then turned into physical objects in their thousands despite each being made in a different location, by a different machine.

This raises some interesting questions:  A viral video or piece of advertising made up of digital bits can easily be deleted, but how do you delete a viral object made up of physical atoms? Simply discarding 3D prints into landfill is unsustainable, and new solutions are necessary that make recycling of 3D prints affordable and accessible to the masses. It is also worth looking at the quantities an object like #3DBenchy is being downloaded and 3D printed, which is clearly in a magnitude similar to injection moulding and the mass production paradigm that 3D printing is supposed to disrupt. While it’s useful to have an object to calibrate and compare 3D printers, it’s also interesting to see that people still want to print and own the same object, rather than being truly individual.

The trend for viral objects is certainly one to watch, and the chapter provides a detailed analysis of this and other emerging trends related to 3D printing and pop culture. If you’re interested in reading the chapter, you may use my author discount code “IGI40” to get a 40% discount, or if you’re at a university you may find you already have access through your library subscriptions. Paul and myself certainly welcome your feedback and thoughts 🙂

– Posted by James Novak