3D Printed Flexible Lens Cover

I’ve said it countless times before, and I’ll say it again – some of my favourite 3D printing projects are the ones which are quick, easy, and either add value to an existing product (e.g. see my 3D printed webcam mount or lucky bamboo holder), replace something broken or lost (e.g. my SUP paddle lock),  or in this case, something missing.

I recently bought an old pair of binoculars (or is it just a binocular?) from an antique store. They came in a pretty beaten up case, and were missing two of the protective lens covers, but overall worked nicely with lenses that weren’t scratched. The lens covers that did come with the binocular were cracking and didn’t really stay in place any more, so it was 3D printing to the rescue.

Planning to use some PolyFlex TPU95 filament from Polymaker to create a soft, rubber-like lens cover, I ended up designing the lens covers to be just slightly smaller than the measured diameter of each lens, 0.25mm smaller to be specific, with the intent of creating a secure friction fit, but not so tight they had to be stretched over the lenses. The design is very simple, a couple of extrudes in Fusion 360, before adding the circular pattern detail around the outside (which was not part of the original lens caps!) to add a personal touch. Now that they’re printed they remind me of beer bottle caps, but the intent was just something a bit rugged and easy to grip without spending a long time trying to be too clever in CAD.

These were 3D printed on a Wanaho Duplicator i3 Plus with an upgraded Flexion Extruder. What’s a Flexion Extruder? Well, you can read my whole series documenting early experiments trying to 3D print flexible materials here, but long story short, a Flexion Extruder is the ultimate upgrade for cheap desktop FDM machines that allows you to successfully and reliably 3D print with soft TPU materials. If you don’t have a Flexion, or a good quality system like the Prusa MK3S which has been designed to print a whole range of materials including TPU, chances are you will end up with a tangled mess of filament coming out the side of your extruder, or worse! They’re just too soft to be forced down into the hotend and come out of a tiny nozzle.

The other trick is getting the right settings to print with – you will find loads of different theories and recommendations online, 3D printing TPU is a bit of a dark art and there are many different types of flexible TPU that require different settings. So getting things right will take some time. This is a good general guide to follow, and I’d reiterate that you MUST print extremely slow – I used 20mm/s for the lens caps. Also, follow the recommendations from your filament supplier, this material from Polymaker was printed at 220°C with the build plate at 50°C. Seemed to be about perfect.

Above you can see just how flexible the end result is, the lens caps easily bend and squash without permanent deformation. If you’ve got any settings you’ve found are reliable, or just general tips and tricks for 3D printing TPU, please comment below to build up some resources for others to find.

Happy 3D printing.

– 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

 

Giving the Finger to 3D Printed Prosthetics

I’ve always wanted to try 3D printing one of the great open source prosthetic hands that frequently pop up in my news feed, and I have finally found an excuse, and a little bit of time, to dip my toes in the water with this prosthetic finger. This is the freely available Owen Replacement Finger, available from the well known 3D printed prosthetic company Enabling the Future. While the design is admittedly quite clunky, it does work, and it is somewhat customisable using the Customizer feature of Thingiverse to fit your hand/finger dimensions.

All the pieces printed in 2-2.5 hours on my Cocoon Create printer, with only a couple of the small details not printing correctly (in particular the guides for the fishing line on the back plate). But nothing critical. Add a small length of elastic cord and some fishing line and you have a basic moving finger. Many of the parts are designed to be fixed to a glove so that when you clench your fist, the finger bends, but for now I’m not interested in creating an extra finger for myself or anything – it’s just a trial as I lead into a research collaboration at university to look at finger prosthetics for some real life patients.

From this small print I can see why the full prosthetic hands make a great project – it’s fun to bring something like this to life with movement that begins to replicate our own human anatomy. Hopefully there will be more like this to come!

– 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

Custom SUP Fin

I’ve recently bought my own Stand Up Paddle (SUP) board, an inflatable version from Flysurfer, which so far is working really well. But this isn’t a product review! My local paddling spots are all very flat, but the fins that came with the board are very surf oriented. This means that when paddling in flat water there is a lot of drag from the 2 outside fins which are angled out from the center line (see the middle photo), and the board doesn’t travel in a straight line – you have to swap hands every few strokes. It’s not a huge deal, but I was curious to see what difference a large single fin would make since most boards I’ve seen use this. Unfortunately Flysurfer don’t sell them, so it was time to get making!

All I did was use my flatbed scanner to capture the original fin shape (the black one in the right photo), trace the top section in Adobe Illustrator since this is the critical detailing to fit with the board, and then add my own shape for the fin based on the shape of some popular fins online. No 3D CAD required. This was laser cut from a piece of clear acrylic, and I used a file and sandpaper to add some shape to the edges. Voila.

Unfortunately I can’t give this particular design 2 thumbs up, it doesn’t perform quite as well as I expected. While it seems a little easier to glide through the water, the fin doesn’t improve the boards ability to hold a straight line – I think it’s a little bit loose in the socket and tilts on an angle in the water. The acrylic might be a little too thin, but it’s a start. I’ll make some tweaks and try again – it’s nice to make something that’s not 3D printed for a change.

If anyone has any experience playing around with different fin configurations or shapes I’d love to hear from you – I’ve read a few interesting articles from SUPguide.com and Neverbored but there’s only so much you can learn by reading, especially when you have to make your own fins because of the limitations of the inflatable board.

– 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

 

A New Year Miracle… Sort Of

A “New Year Miracle” might be overstating things a bit, but these are the first useful prints I’ve had from my Solidoodle Press – and I use the word useful instead of successful, awesome or great because they are only useful in the sense that they prove what I needed to in a rough prototype – they fit. But if you look at the surfaces they are far from pretty, and for every one of these parts that was made another couple were thrown out. But compared to my last attempts, or anything else from this machine, it’s something!

These parts are just some little grommets which are designed to plug into a soft foam or neoprene material – some electronics get mounted within them and the rest is… well a bit top secret at the moment. Yes the usual excuse, but that’s how research projects go.

I’m continuing to get the slipping problem I wrote about in my last post using the Solidoodle and think I have an idea why – it might be something to do with the motor that drives the forward/back motion of the print head. I’m noticing that after about only 20 minutes of use the slipping becomes a problem, consistently, and that this motor is getting extremely hot, like hot enough to burn you. Which I don’t think should happen since it’s got nothing to do with the hot end of the print nozzle. So it’s possible that when it gets this hot, the motor starts failing internally. So normally the first one of these little grommets prints out fine, and then things go wrong and I shut down the machine for a while and start again. Obviously it’s manageable on such a small part, but means printing anything useful at a larger size will never happen.

Come on Tiko, I need you!

I’ve found a thread on the Soliforum from someone with the same issue and added my observations and a photo. Hopefully there are some solutions that people have found, there are a few suggestions listed already but I’m doubtful whether they’re going to solve my problems. I’ll try again soon.

– Posted by James Novak