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 πŸ˜‰

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

– 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! πŸ˜‰

– Posted by James Novak

3D Printed Prosthetic Research

As a university researcher, it often takes a long time until I can actually share my work publicly. As a result this blog often only tells part of the story, for example I recently posted about 3D printing a prosthetic hand by e-NABLE. What I didn’t say is that this was part of research into adapting the design to perform different tasks. Recently undergraduate product design student Cory Dolman worked with me to prototype some new concepts, and his work has been picked up by UTS who created this great video about his process and the ideas we’ve been bringing to life. You can also read all the details on his blog which was maintained during the project with me here.

For anyone who is yet to realise the opportunities of 3D printing technology, hopefully this video goes some way to showing how quickly designers like Cory and myself are able to iterate designs, constantly testing our ideas and expediting the design process. We hope that as we refine these designs, we will be able to share them back into the e-NABLE community, and allow anyone with access to a 3D printer to not only benefit from the prosthetic, but also continue to iterate and improve it collaboratively. This is what excites me about 3D printing – it’s not just about the technology, but what it enables.

– Posted by James Novak

Organic Models Grown in Grasshopper

During November 2017 I was lucky enough to be involved in a 2-day workshop run by Lionel Dean from Future Factories. Lionel has been working with 3D printing for many years, and his work is very inspirational – I’d recommend taking a look at his projects which all use algorithms to generate complex, one-off products often 3D printed in precious metals like gold. The projects really highlight the capabilities of 3D printing and push the boundaries of what is possible.

The workshop focused on using Grasshopper, which runs as a plugin for the 3D modelling software Rhino. If you’ve been following this blog for a while you’ve probably seen a few videos and demonstrations as I’ve been learning the program, including my successful Kickstarter earlier this year. The video above is the final simulation produced by the end of the workshop, which was an exploration of mimicking natural growth processes, similar to a sprouting seed. It’s not perfect, but definitely highlights the opportunities of using algorithms to design, as opposed to manually creating a singular static form. In Lionel’s work, he often uses these forms of growth to allow people to essentially pause the simulation and have the particular “frame” 3D printed as a custom object.

20171220 Grasshopper Code

For any fellow Grasshopper geeks, above you can get an idea of the code used to generate these sprouts. There is no starting model in Rhino, it is entirely built from this code. Hopefully this will influence some future projects…

– Posted by James Novak