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

Giant 3D Printed SUP Fin

Behind the scenes I’ve been working on a Stand Up Paddle (SUP) fin project for quite a while now, 3D printing many prototypes, and more often than not, failing! There is more to this project than meets the eye, but for now the details are under wraps. However I thought it might be interesting to share some of the 3D prints in case anyone feels inspired to give it a go themselves.

The design pictured above is the first one that worked successfully without breaking or having other technical issues. Printed in 4 pieces on my Cocoon Create due to the size, it required a bit of gluing, and as you can see from the pink highlight, a bit of gap filling with a 3Doodler Pen (if you want to know more about using a 3D printing pen as a gap filler, check out one of my previous posts all about it). As a result the fin is about 400mm long, huge compared to the fin that came with the board (which for any SUP fans out there is a Slingshot G-Whiz 9’4″)

These images show some of the breakages I’ve had due to layer delamination – unfortunately the optimal way to print the 4 pieces in terms of minimising support material and warping is vertical, however the optimal orientation for strength is laying down on the flat sides (similar to the image on the right). A bit of an oversight on my part I’ll admit, however I was genuinely surprised how much force the flat water put on the fin. Another issue may be the minimal infill, which was also beefed up in my later prints to add internal strength. There is always a delicate balance between print orientation, layer strength and infill in 3D printing, to name just a few!

The main thing is that the fin prototype now works, and I may have a more advanced version being printed using Selective Laser Sintering (SLS) as I write this… If you keep an eye on my blog by subscribing below, you may just get to see where this project is going 🙂

– Posted by James Novak

Goodbye 3D Printing, Hello 4D Printing

Many people I talk to at events and workshops are only just catching on to this whole 3D printing thing, but did you know some of the exciting research in this field has already moved on to the next dimension – literally?

4D printing might sound a bit weird and wacky, but it basically just means something that has been 3D printed, but changes its shape afterwards since time is the fourth dimension. So a 3D print that changes over time. Skylar Tibbits from MIT is really one of the pioneers of such a concept, so if you want to wrap your head around the concept this link to his Self-Assembly Lab at MIT will have some more videos to explain what it means. Having spent some time lately writing about 4D printing for part of my PhD, I thought it was time to give it a go, taking inspiration from the Active Shoes created by the Self-Assembly Lab.

As you can see from my very rough video, it’s actually quite easy to do. All I did was create a few concentric circles in CAD with a 0.2mm thickness so that they would print only 1 layer thick on my Cocoon Create 3D printer. I then stretched some material (from an old pair of stockings – not mine I swear!) over the base plate and held it in place with clips. A slight adjustment to the height of the base plate to make room for this material and 1 minute later it was done.

The result is really cool (I think) for something that only took 1 minute to print. It’s certainly not perfect, but shows a lot of opportunity for the future of fashion design. If you wanted to only use 3D printing to create this shape it would easily take 20 minutes or more on a standard FDM printer, so I think some more experimentation is required.

– Posted by James Novak

3D Printed Enclosures Are So Rewarding

OK so some people might look at this and think it’s just a box, but when you stop and think that 2 hours ago this “box” had never before existed in the entire span of human history, and that it was made on my desk, with a printer, well that’s pretty cool!

That might be over-dramatising things just a little, but there really is something very rewarding about 3D printing a custom enclosure to contain your electronics. I have quite the collection now, for example an Arduino enclosure and a Wiiduino. In this particular case a custom PCB has been manufactured, and we need to contain it in something for trials, keeping all the wires and mess tidy and giving the appearance of a real wearable product as it one day could be.

The PCB is about the size of an Arduino Uno, with a lithium battery that needs to be housed inside as well. I started by modelling the PCB in Solidworks, just as I have done in previous projects. While many people would only bother creating a simple block model of the overall dimensions, I’ve gone to the trouble of accurately modelling all of the key components like LED’s, buttons and connectors as shown above. This means that in the enclosure design, I’ve been able to play with form, giving the design tapered edges to make it seem slimmer, and accurately place holes and details for the various components. In doing so, the first 3D prints fitted successfully, saving time stuffing around later. These were printed on my Cocoon Create, which is still going along nicely, thanks Aldi!

I’ve also opted to use 2 screws to secure the enclosure halves, as snap details on such small enclosures can be fiddly when using desktop 3D printers – if you don’t print them in the right orientation, they just snap off. With holes already placed on the PCB, it makes sense to use these to both secure the 2 shells, and hold the PCB in place. So you get the full picture, here’s the 3D model for you to spin around.

IMPRINT PCB Case 01 by edditive on Sketchfab

Lastly my tip is to always add some sort of logo or name to the enclosure – it just makes it really pop, and takes no time at all to add. Even a rough prototype should look good!

– Posted by James Novak

 

Mesostructure

Mesostructure… Is that a real word?

It sure is, and while the definitions are quite complex, the best way to understand a mesostructure is to look at some images of them. The top left photo is actually a nice 3D print of one you can download free from Thingiverse, and if you’re after something to show people the interesting things that can be 3D printed, this is a great example. I’ve printed them in ABS plastic, but the structure itself is both rigid and flexible. 3D modeling them can be a good little challenge – hopefully whatever CAD program you’re using has some great patterning and mirroring tools! I used Solidworks and really made the most of the parametric functions to allow quick and easy changes in the future. By changing the density of the structure, or simply increasing the thickness of them, you can really play around with the flexibility of the structure.

The other 2 images are actually my first little attempt and having a functional use for a mesostructure. I’m trying to isolate some small vibration motors, and this was one of the ideas building upon a previous round of prototypes that I’ve posted. It’s just like building in some springs between each motor. Nice and flexible and only 25 minutes to 3D print on my Cocoon Create, which is great when you’re trying to test and iterate multiple ideas quickly. Below is the 3D model for you to spin around.

Mesostructure section by edditive on Sketchfab

– Posted by James Novak

Beyond FDM and the Future Printing Bureau

3D printing is a fantastic technology, and the quality of the prints from a desktop machine like my usual Up! Plus 2 are pretty awesome when you think about the fact that they’re produced on my desk! But at some point you’re likely to reach the limits of what can be achieved on such a machine, either through material limitations, size limitations, or in this case in the complexity of the parts themselves.

The parts pictured above are the next stage of development from some of the 3D prints I showed in a post a couple of weeks ago, with some of the patterns and ideas very similar. However now that I’m trying to move beyond relatively “flat” prints into these complex shapes that fit a 3D curved surface, the limitations of a desktop FDM machine become clear. The amount of support material needed, along with the delicate nature of the designs means that pieces of each part were broken during support removal, and on top of that, many areas of the prints simply didn’t print out clearly with lots of loose threads of ABS plastic floating around.

While these prints are enough to visually communicate a design idea, they simply aren’t accurate enough to allow us to physically test or embed electronics in. Therefore it seems we have reached the limits of what we can trial using desktop 3D printing, and must now look at moving to SLS or a similar high-end process, which of course means paying a lot more for prints. It also means that rather than being able to move back-and-forth between CAD and 3D printing multiple times a day, we will be waiting weeks while parts are printed and shipped to us – so a lot more pressure to really take what we’ve learned so far from these prints and ensure that the next set which we produce are going to work.

The reason I write about this is because there is always a lot of talk about whether everyone will one day have a 3D printer in their home. While it’s certainly a possibility, there are obviously limitations to the sorts of products people would be able to print with an affordable home machine. So why won’t everyone just have a SLS machine in the future I hear you ask? Well at the moment my university has purchased a SLS machine, however an even bigger challenge than raising the few hundred thousand dollars to purchase it (which of course will dramatically come down in price now that the patents have expired) is now how are we going to use it safely? It has an enormous checklist just to set it up including requirements for anti-static flooring, appropriate measures and warnings about the dangerous class 4 laser, being installed somewhere that has absolutely no vibrations around it (so not near other types of machinery), advanced air filtration and exhaust systems in the room, an eye-wash station next to it and many more… These don’t sound like the sort of renovations your typical home user is likely to invest in!

So in my opinion it is far more likely that we are going to see even more Shapeways style service bureaus pop up, which is already the case through Staples in the USA and now Officeworks in Australia, where you will take your files to get printed in your local area. All the costs, maintenance and training is covered by these commercial businesses, and we all get to enjoy the benefits. Until then, it looks like I will be placing yet another order for parts on the other side of the world so we can test out these designs properly.

– Posted by James Novak

Prototype or Fail

These 5 different concepts continue from my last attempt to test a new design for a research project I’m working on – however these have been done on the ever-reliable Up! Plus 2 3D printers, not my useless Solidoodle Press! What a difference it makes…

Without going into specific details (the hush hush clause!) it was a great example of how important it is to test your ideas in the real world, you can’t rely on just what you see on screen and in your imagination. Each concept attempts to solve “the problem” in a slightly different way, and in fact the solutions we thought would work best didn’t, and the obscure ones that we didn’t really think would work very well have proven to be the best and are now evolving into the next stage of development. Without testing these we would never know, and could’ve invested a lot of time and money into something that wouldn’t have worked at all. So as the title says, prototype or fail.

Thanks to 3D printing it is very cheap and quick to test ideas, something that not so long ago may have taken a lot of time, skill and effort to make by hand, and thus limited the extent to which an idea could be explored. Having experienced these situations in professional practice where only a select couple of concepts could be squeezed into the budget (with plenty of kicking and screaming from clients), it’s amazing to now experience just how quick numerous ideas can be tested, with the above prototypes printed in an afternoon and analysed the next day in a 1 hour meeting. Done. We can move onto the next stage very quickly and with a lot of confidence in our direction.

– Posted by James Novak

 

Grasshopping Continues

While I seem to be spending more time in CAD than 3D printing at the moment, I’m enjoying it just as much. I’ve just finished a few more Grasshopper tutorials (continuing on from my last post) and challenged myself to build a hex grid that changes the diameter of each piece, and also it’s extrusion length, based on proximity to 2 control points. There are a few advanced things going on here that improve upon what I had in the last post:

1. The individual cells won’t get so large that they overlap. At their maximum size they will maintain a small gap from each other.
2. The grid itself is also parametrically controlled, so spacing can be modified using 2 sliders, or expanded to include more elements.
3. The length of each extrusion is directly related to the area of each individual hexagon.

Below is the way I created it in Grasshopper.

This is such a powerful tool and I’m still only just scratching the surface. Hopefully over the coming week I’ll get to playing around with the Firefly plugin that pairs with my Arduino. If I could control the 2 attractor points in this model from the Arduino for example, that would be pretty amazing!

– Posted by James Novak

A Step Towards Eye Tracking

While these may just look like some pretty boring 3D printed glasses, there’s actually a lot more going on than meets the eye. Researchers at the University of Newcastle asked me to CAD model a copy of the SMI Eye Tracking Glasses to be 3D printed. The reason: the real glasses cost around $12,000, and before they let their subjects loose with them, they want to give out 3D printed sets to become accustomed to prior to donning the real set. Sounds like some clever thinking to me, and just another great application of 3D printing.

Unfortunately all I had to work with were 4 rough dimensions and the images on SMI’s website, but I think these should be close enough for this particular application. I’ve modeled them to be 3D printed in a complete assembly using SLS, meaning that there is no assembly required and the hinges are less likely to break. Through Shapeways my set come in under $25! However in order to test my model, I’ve chopped it into pieces to allow printing on my Up! Plus 2 home printer, which is too small to print the glasses in one go. The first image above shows all the individual pieces, with the 2 frame pieces already glued together through the nose section.

The only nervous moment was gluing the end-caps of the frame with the arms inside (creating the trapped hinge motion), since it would be very easy to accidentally glue the arms at the same time! There are also a few distorted sections where the prints lifted off the printing plate slightly during the print – but again, this one is just to test how accurate the 3D model is, with the final prints being sent away for SLS printing. I wonder if a company like SMI should be supplying something like this as part of their kit?… Food for thought with the ease at which the files can be 3D printed.

While I can’t share the files for this design, if you’re after some glasses you can 3D print why not start by checking out a previous project where I 3D printed new arms for my aviators? I’ve shared the files on Thingiverse so anyone can make them.

– Posted by James Novak

Leaving My Mark on the World

Things are starting to come together and I could not be more excited!

I’ve just made my first stamp using the ‘edditive‘ 3D printed logo and some ink on cardboard – PERFECT. I know stamping is such an old technology but there is something extremely satisfying about testing an idea like this and having it turn out exactly the way you want. And all designed and 3D printed within 30 minutes – now that’s the power of 3D printing.

– Posted by James Novak