3D Printed Knits

191115 3D Print Knit

Did you know it’s possible to knit using a desktop 3D printer?

This has been some work I’ve been doing in the background for a little while now and combines all the benefits of digital design with craft-based hand assembly. OK, so you can’t print with soft yarn (yet), but by printing thin geometry you can create some relatively soft and flexible knits that are unlike the typical chainmail assemblies often used in 3D printed fashion/textiles.

The trick to this is to simplify the knit into individual pieces, which can be 3D printed flat on the build plate. This makes printing extremely fast, also known as a 2.5D print which I’ve written about in a previous blog post. While one of the benefits often discussed about 3D printing is the ability to produce complex assemblies as a single part, in the case of a knit, this will result in significant amounts of support material, and the need for quite bulky geometry to ensure the knit geometry is strong enough. However, by printing separate components, these problems are avoided, and you can have some fun manually connecting the loops together while you wait for the next print.

Additionally, the new opportunity of 3D printed knits is to create completely new patterns and geometries in CAD software. This has been the focus of my newly published paper called A Boolean Method to Model Knit Geometries with Conditional Logic for Additive Manufacturing (free to access). In it I detail how to set up an algorithm in Rhino with  Grasshopper that will allow customisation of loop and float structures for a knit, the sort shown in the top picture. If you have some experience with the software, you can follow the process outlined in the paper to set up a similar system, and begin modifying parameters and geometry to create completely new knits that would not be possible using traditional knitting techniques.

191115 Grasshopper 3D Knit

As shown above, the Grasshopper code gets quite complex so is not for the feint of heart, but if you understand boolean logic, and have used Grasshopper, I’m sure you can build this! And if not, have a go at modelling some knit geometry in your favourite CAD package and print it out – you can keep printing on repeat to extend the size of your “knitted” textile, this is how some of my early tests were done. If you start by modelling some rows of circles, then connect them together, this will get you close to a knit structure.

Happy 3D knitting.

– Posted by James Novak

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

Hex Business Card Holder Tiles

IMG_20190507_Hex Business Card Holder

A new office and a new excuse to design and 3D print something! Like many people I end up with piles of business cards that I don’t know what to do with. They clutter my desk, get lost, and ultimately end up in the bin. Sure, there are loads of fancy solutions at stationery stores, and plenty of apps to digitise them, but where’s the fun in that?

Now that I have pinboards wrapping my desk I decided to design a simple, easy to 3D print hexagon business card holder that could be pinned up out of the way. After all, everyone loves hexagons right? While the design is extremely simple (a few extrudes and cuts in Fusion 360), the trick was to model it in a way that would allow it to be 3D printed without any support material – so, as you can see from the layers in the photos, they are (perhaps counter-intuitively) printed in the same orientation they are used. This was an important thing to consider during the design process, with no horizontal beams and all angles >30° from horizontal, and is an important part of what’s known as Design for Additive Manufacturing (DfAM).

There is a small hole and recess to fit a thumb tack, and you can 3D print as many as you need. As usual you can freely download and print this design for yourself from Thingiverse, Pinshape, MyMiniFactory or Cults, and I’d love to see photos of how big you can make your Hex Business Card wall!

Happy 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.

Print

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

Shim the 3D printed shim

IMG_20190226_3D Print Shim Doorstop

We’ve all experienced that wobbly table at a cafe and struggled to wedge coasters and napkins under the legs to balance it out. This is where you need a shim, a small wedge that can fill the gap and ensure your drinks don’t go flying. Shim is also fun to say, quick to 3D print, and a good test of your print settings due to the top surface exhibiting the stair-stepped effect.

There are many designs available on popular 3D printing file websites, but I just wanted one that was a useful size (easy to carry with you in a small bag) and that said what it was. So here it is, Shim the shim! You can download it for free on Thingiverse, Pinshape, Cults or MyMiniFactory. Alternatively you can follow the basic outline of the design process below to make your own from scratch in your favourite CAD software. It’s similar to some of my previous designs including an “edditive” desk logo which might give you some inspiration for different ways to use text in 3D.

IMG_20190226_Solidworks TextShim was designed in Solidworks by using the text tool on the top sketch plane. The key is to squish all of the text together so that the letters intersect, meaning they will 3D print together as a single object (in Solidworks you can simply change the spacing of text within the text tool). The text was then extruded 10mm, creating solid geometry. All you need to do to create the wedge shape is then slice a triangular portion off the top, which in Solidworks uses the extruded cut tool. Save to STL and 3D print, it couldn’t be much simpler!

This is a nice quick 3D print and could easily be used as a keyring or give-away item, especially if you design your own. Enjoy, share and print!

– Posted by James Novak

3D Printed Chainmail: Size XL

20181030_3D Print Chainmail

If you’re into 3D printing like me, chances are you’ve already 3D printed chainmail and been excited by the ability to produce something that is made of multiple parts already assembled and ready to go. If you’re new to 3D printing, what you might not realise is that because you are printing objects in small layer increments, you can print these layers in such a way that different pieces become trapped within each other as the print progresses, permanently assembling them together. This means that something like chainmail, which has been hand assembled for thousands of years one link at a time, can now be printed with all the links in place.

One of the most popular examples in recent years has been from well known designer Agustin Flowalistik, whose unique design of chainmail has been downloaded over 100k times already on Thingiverse! Click here to download the file for yourself and add to this growing number. After one of my previous posts about the new Wanhao Duplicator D9/500 printer, I wanted to see how it would handle the intricate geometry, however, at 200% the scale. Go big or go home!

Well, as you can see from the photos it worked quite nicely. With the large 0.8mm nozzle the layers certainly look rough and messy – this print isn’t going to win any awards for being pretty. But it worked, and on this sketchy 3D printer that’s the most important thing at the moment. One of the nicest things was peeling it off the magnetic flexible build plate of the D9, which you can see in the first picture above – no hacking away with a spatula which is one of the positives of the printer. The links freely move and because of the large size, the chainmail has quite an industrial feel about it. Very satisfying.

So I think I can chalk this one up as a win on the Wanhao D9, which I think brings my score up to about 2 wins, and too many failures to count… Not great but after a firmware update I hope there will be some more wins to come.

– Posted by James Novak

3D Printed Medal and Trophy

IMG_20181024 3D Printed Trophy Medal

As a product designer focused on 3D printing in my job at the University of Technology Sydney, it was no surprise that I found myself being asked to design some 3D printed awards for the end of year 2018 Vice-Chancellor’s Awards for Research Excellence. And while not receiving an award (yet!), I think it’s even more fun to get to be designing them – besides, now I can print them out for myself!

I was asked to design 2 different awards which you can see pictured above. The first were a set of 3 medals, and my only brief was to have them 3D printed in metal, and for them be approximately the size of previous medals given out for the awards. I based my design on a spinner concept which I’ve previously printed, with an important feature being the cone-like details which hold this assembly together when printed as a single part. There is no support material required, with one of my goals being to highlight through the design the capabilities of 3D printing in metal. For recipients, my goal was to create something playful and engaging, rather than most medals which are kept in a case and quickly forgotten. Thanks to my friend Olaf Diegel at Lund University for printing these in aluminium and sending them to us in time!

VID_20181023_095036 GIF

For those familiar with metal 3D printing (Direct Metal Laser Sintering to be specific), you can probably guess there was a lot of manual post-processing of these medals to remove the base supports and polish the surfaces. Below you can see the medal as it comes out of the printer on the left (once cut from the build plate), and the final polished version on the right. All of the base support material you can see in the raw version had to be filed away while held in a vice, before going through a lengthy process of polishing. Slow, painful work, but you haven’t truly 3D printed in metal until you’ve gone through this process, it makes peeling away plastic support material from FDM prints seem like child’s play!

cof

The second award was a trophy which also continued with the 3D printed assembly concept. My only brief for this design was for it to be printed on our own HP Multi Jet Fusion 3D printer, which is very similar to SLS printing. Many of us have seen the “ball in a ball in a ball” type of prints which are often shown at 3D printing expos and events, and I built off this to incorporate a lattice frame to contain the balls. The basic design was done in Solidworks, however, the balls were just solid spheres at this stage. I then exported them into Meshmixer in order to apply a lattice structure to them, using 2 different geometries. All parts were then imported into Meshmixer in order to export them as a final fully assembled file ready for printing.

VID_20181024_134222 GIF

A little bit of laser cutting and timber work by a colleague really helped bring the design to life, and again, the trophy encourages interaction and play. Congratulations to the winners and finalists, I hope you enjoy your awards as much as I did creating them. With any luck I might get to design them again in 2 years and bring one home myself for real! 😉

– Posted by James Novak

Using Every Last Drop

IMG_20180917_Webcam 3D Print Mount

Perhaps it’s the result of spending 10 years as a poor uni student, but I really like to use every last drop of liquids: sauce, toothpaste, shampoo and yes, deodorant. Many of the roll-on style deodorants, such as those from Nivea, have a domed lid, meaning it’s impossible to tip them upside down as liquid is running low and store them so gravity can do its thing. In my mind, this is a design flaw in the packaging (although from Nivea’s point of view, this is a great way to keep people buying more products more often).

I had originally planned to create my own design to solve this problem, however, after a quick search on Thingiverse I was pleasantly surprised to see many people had already beat me to it! There are plenty of designs to choose from, and I decided on this helix design for its interesting form. Click here to download the file for yourself from Thingiverse.

The print took just over an hour to complete, and as you can see from the pictures, it does exactly what it promises. I also streamed the 3D print on my YouTube channel, so if you like watching the grass grow, here is an hour of entertainment just for you! Make sure you subscribe if you want to be alerted of the next live 3D print 🙂

– Posted by James Novak

3D Printed Webcam Mount

IMG_20180917_Webcam 3D Print Mount

Whenever I travel I always have a small Guerrilla tripod to easily mount my cameras just about anywhere – the flexible arms make it perfect for wrapping around handrails or quickly levelling on uneven surfaces. Which made it my first choice when it came to mounting an old webcam so I can begin streaming my 3D prints to Youtube!

I’m seeing a lot of people like @wildrosebuilds posting awesome time-lapse videos of their 3D prints, and plenty of tutorials online showing how to build quite elaborate rigs to do so. I don’t really have time to deal with all of the video editing for each print, but the opportunity to live-stream prints directly to Youtube seems like a great way to share what I’m working on in real-time, and also allow me to monitor prints without having to physically be with the printer. However, webcams aren’t designed to mount to the typical screw mechanism used by tripods/cameras, so I had to design my own bracket to allow me to mount an old Logitech C270 HD webcam to the tripod.

The top right image shows the small slide-in clip that screws to the underside of a camera, and locks into the tripod. My first step was to reverse engineer this part with a set of calipers, modelling the geometry in Solidworks. I then added a vertical element to attach to the webcam, which has a hole on the back normally used by a bracket attaching the webcam to a computer screen. An extra lip on the front to hold the webcam in a vertical orientation, and voilà!

The blue bracket has been printed on my Wanhao Duplicator i3 Plus in PLA, and a screw I had lying around holds the webcam to the bracket. A nice little solution that should see some action very soon. Subscribe to my Youtube channel or follow me on Twitter to be alerted when I begin streaming prints, I know it can be a bit like grass growing but watching 3D prints is still addictive to me. If you’d like to download this design for yourself, you can find it on Thingiverse, Pinshape and Cults – feel free to make your own modifications as needed and share, I know the C270 is quite a popular webcam.

– Posted by James Novak

UPDATE: If you want to see my first live-stream using this webcam mount, here it is:

Check out my channel to see more, and subscribe to be alerted when I go live.