3D Printed Ninjaflex – First Test

20180406_Ninjaflex Wanhao

I’m sure if you’ve been 3D printing for even a short time, you’ve heard of Ninjaflex – a brand of flexible filament for your FDM printer that has rubber-like properties, rather than the usual rigid plastic parts that are more common with ABS or PLA filaments. While I’ve known about them for many years, I’ve never risked clogging my printer after hearing some bad experiences with these softer materials. Until this week!

I’m currently working with fashion postdoctoral researcher Mark Liu, who purchased a Wanhao Duplicator i3 v2.1 for some of our research – not coincidentally, it’s identical to my home Cocoon Create 3D printer. We decided to give the Ninjaflex a go to see if it would print, and if so, what sort of quality we could get since the printer and replacement parts are cheap if we really screwed up! Photographed above is one of our first successful prints, although the truth is we had quite a few failed attempts getting to this point as we experimented with settings and carefully watched each print. The primary settings we are using for these first tests (based off the recommended settings for Ninjaflex which are available in the Printing Guidelines) are:

  • Extruder Temperature: 230°C
  • Build Plate Temperature: 40°C
  • Print Speed: 15mm/s
  • Layer height: 0.2mm
  • Retraction: 5mm (I think this is too much and we will try 0mm or 1mm)

These may not be perfect yet, and I’m keen for anyone’s feedback on what’s led to more successful prints with these soft filaments. The main thing we’ve noticed is that the soft filament is challenging for the extruder to push down into the nozzle and force out the tip – it is quite common for the nozzle to clog and filament to keep feeding through until it comes out the back of the extruder. Luckily nothing has jammed up yet, you can pull the filament back up out of the extruder and try again. With a bit of a search online, it seems that some 3D printable parts may solve this problem, in particular this modified Extruder Drive Block available on Thingiverse which closes the opening where the filament likes to escape, and will hopefully better force it down through the nozzle. The video below from Wanhao USA helps highlight the problem, and how this 3D printed part can fix it.

It’s early days with this filament, and I know the stock extruder of the Duplicator i3 is really not optimised for this type of material. But it can be done, and I’m sure with some tweaking can be made more reliable. Stay tuned as I am currently printing the new block to install on the Duplicator in the coming days, and will report back with results.

– Posted by James Novak

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Oh That’s Handy – 3D Printed Prosthetic

20180114_e-Nable Prosthetic Hand

If you’ve been paying any attention to 3D printing over recent years, no doubt you’ve seen at least a few 3D printed prosthetics. From the Iron Man prosthetic arm to the prosthetics being 3D printed for our animal friends, 3D printing is ushering in a new generation of low-cost, customisable prosthetics. Perhaps you’ve even seen my build of the fully robotic InMoov hand which has been documented on this blog.

At the extremely affordable end of the spectrum for humans, Enabling the Future (also called e-NABLE) is one of the most well-known names, developing a range of  open source prosthetics since 2013, which can be freely downloaded, printed, assembled and sent off to those in need. As part of my research I have wanted to build one of the e-NABLE hands for a while now to understand more about them, particularly in comparison to the more complex InMoov robot arm. As pictured above, I’ve finally got around to printing the Phoenix v2 hand, which is wrist actuated to open/close the fingers.

When you look at all the details, it really is a clever design which is optimised for 3D printing on a desktop FDM machine, with almost no support material or waste, and tolerances that fit really well together. Anyone with a 3D printer could assemble one of these, most of the non-3D printed parts can be sourced at a local hardware store or found in your shed (screws and fishing line). The instructions are very clear, and there are loads of videos to help demonstrate the assembly process and how some of the technical aspects of the hand work. Because I printed in ABS rather than PLA plastic, the only small hurdle I had was in the thermoforming process of the gauntlet (the bent white piece that mounts to the users arm), which required me using a strip heater in the university workshop. If you find yourself in a similar situation, you can check out the details which were posted in one of my previous posts. However, I recommend using PLA if you have the choice to make this part easier, only requiring some boiling water as demonstrated in this video. In itself, this is a really cool technique that I will use in the future to create stronger parts; you can always learn a lot from 3D printing other people’s designs.

Overall the e-NABLE community really has done a great job in refining this design over the years, and I’m already working on some of my own iterations which will hopefully be fed back into the e-NABLE community in the future. If you’re looking for a project to build and learn from, or potentially getting involved in the community and building hands for people in need, Enabling the Future is definitely worth researching.

– Posted by James Novak

Giant 3D Printed SUP Fin

20170511_3D 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″)

20170511_3D SUP Fin

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

Vacuum Forming Over 3D Prints

3D printing is awesome for creating so many things – I’ve certainly lost track of how many things I’ve made and shared on this blog! But it’s also fantastic to use alongside traditional manufacturing techniques – moulds for casting, jigs to help in assembly, or in this case, as moulds for vacuum forming. The short video above shows this process being demonstrated to the Intro to 3D Printing class at my university. The faces are 3D printed from 3D scans in ABS plastic, and we are using 1.2mm PETG plastic for the vacuum forms.

collage

The results are really detailed – even the layers from the FDM process have been transferred to the vacuum forms as a texture! After a few of these being created some visible melting of the prints was visible, mostly on the chin and nose where the initial contact with the hot PETG sheet is made – so I’m not sure how long they would last if you were to make 100 of these or more. But a great example of how quickly and easily you can create many copies of a part using the relatively simple method of vacuum forming – you could probably create one of these every 2 minutes, with the plastic only needing 23 seconds to heat before the vacuum process. I know I’ve got some ideas from seeing this.

– Posted by James Novak

3D Printed “Marshmallow Challenge”

collage

Have you ever done the Marshmallow Challenge? Chances are you’ve done something similar at school, or if you’ve ever been to a team building workshop it’s a pretty popular creative exercise. Basically teams must build the tallest freestanding structure they can in 18 minutes using 20 sticks of spaghetti, a yard of tape, a yard of string and 1 marshmallow on top. Tom Wujec has been running these challenges for many years and presented a great TED talk if you want to find out more about the challenge and what can be learned from it.

Well now I’ve put my 3D printing twist onto the challenge, running what turned into a very competitive series of workshops for the Intro to 3D Printing course at my university. Teams were given a selection of materials we had readily available for model making (20 paddlepop sticks, 1 paper plate, 2 paper cups, a few drinking straws, a length of masking tape and a length of string) and given a very simple brief – build the tallest freestanding structure possible during the 2 hour workshop. The catch:

Teams were each given an UP Plus 2 3D printer and laptop with Solidworks, and could print as much as they wanted to help build the structure.

Now that makes things interesting! These are first year students only new to CAD and 3D printing, so what can they both design and print in such a limited time? Do you print lots of small things, or 1 big thing? How can you tweak the 3D print settings to get things printed as quickly as possible? What do you do when your print doesn’t work? It turns out that this challenge can teach you a lot about 3D printing, and how to rapidly test, prototype and build without wasting any time like in the normal 6 week projects.

As you can see from the photos, the results are very impressive! The winning team built a structure up to 249cm, which basically meant they used all the materials end-to-end and could not go much higher even if they had more time. This team 3D printed small little rectangular connectors for the paddlepop sticks, and with a lot of delicate balancing, managed to get their structure stable at the very last second. Much much higher than I expected when I set this challenge! They were in a very close battle with the team that came second for the day, reaching 238cm with a slightly different connection method where they used 3D printing to connect the paddlepop sticks to the cups. What you might notice with the top 3 teams is that 3D printing was used for small connecting elements that could be quickly printed, whereas some of the other teams (eg. 4th place who I only have a photo of part of the structure) were 3D printing much larger bases and simply ran out of time to push their structures quite as high.

All of the students were very involved and motivated by this task, it’s something I will run again in future classes and 3D printing workshops as a way to push the limits of the 3D printers and break them out of being so precious about what comes off the printers. It also gets them thinking about how to combine 3D printing with other methods of prototyping, you don’t necessarily need to 3D print every part of your design as it’s quite a slow process, particularly for FDM machines. Feel free to make your own twists on this challenge in the classroom, and I’d love to see your results! Maybe the 3D Printed Marshmallow Challenge will be the next big thing?

– Posted by James Novak

When Layer Orientation Matters

20160819_Meshmixer Plane Cut

Often when you are 3D printing the main thing you think about is how much support material your print will have, and you orient your print to minimise this – reducing material waste, print time and any manual post-processing to clean up the print. However sometimes the best print orientation for these reasons is not the best for mechanical strength, and I’ve just discovered this with one of the parts for the InMoov robotic arm I’m currently building (see the first collection of 3D prints in my previous post).

The “RobServoBedV6” part is where the 5 servo’s connect that control the individual finger movements, using screws to fix them in place. However some of the stands are splitting as I screw into them as shown in the photo above due to the layer orientation. Yes I could use super glue to fix them, but the split will just happen  somewhere else. So I’m going to completely cut the stands away from the part, and re-print just these stands in a different orientation to improve their strength. This is where the free program Meshmixer comes in very handy, and I’ve previously published a few examples of how to use it for my friends at Pinshape – just click here to find out more.

In the top right image you can see the first step of using Meshmixer to edit the STL file. I have used the Plane Cut tool to slice away the bottom plate, and then repeat the process to remove the other 2 segments which seem to be strong enough for the screws at the moment. This leaves me with the 2 stands that I’m having issues with. These can now be exported as STL’s ready to 3D print (orientation is not important here, this will be set in my 3D print software).

Cura from Meshmixer

I’m printing these parts as we speak on my Cocoon Create 3D printer, and have used Cura to prepare the parts and get the G-code. As you can see to the left, I have oriented the parts so that the layers are perpendicular to the original orientation, meaning that when I screw into them, the force from the screw will not pull the layers apart. Super glue will hold these replacements onto the original part really well as they are printed in ABS.

If you are designing your own parts from scratch in CAD and intend to screw directly into them, keep this issue in mind. However if you’re downloading a STL where modification isn’t as easy, knowing this simple trick in Meshmixer can really help you repair and improve a part rather than trying to re-print it from scratch and potentially use a lot of support material in a different orientation.

– Posted by James Novak

Brimming with Success

20160712_3D Print Brim

Excuse the headline pun, but this post is all about 3D printing using a brim, which evidently can really improve your success rate with large flat surfaces.

For those not familiar with a brim, it’s an option in some 3D print software (such as Cura) that lays down an extra width of material around your object and attached to it, one or two layers tall. You can see the brim around my enclosure in the top left image. Essentially this extra material creates a stronger bond to the build plate, helping to fight the contracting forces of the cooling plastic that can commonly cause warping. Of course there are many other ways to combat this, including laying down some glue or adhesive spray, printing the part in a different orientation, or using an enclosure to keep the print warmer so there is less warping from rapidly cooling plastic. However these aren’t always an option, so using a brim can be a really effective solution that only wastes a very small amount of extra material.

In the top right image you can see my first attempt at printing this enclosure half, which is very clearly warped as the outer edges lifted up from the plate under the contracting forces of the cooling plastic. Support material was used, but nothing else. In contrast, you can see the middle image which is the end result once the brim from the left image was removed – perfectly horizontal! This is really important for this design since it is one half of an enclosure, and the warped version simply won’t fit properly with the other half.

20160712 CuraIt’s certainly not something needed for every print, but for large surfaces it’s proving to be very successful. If you’ve had similar problems with warping and haven’t tried a brim yet, it’s worth giving a go – you can see where to access this setting if you are using Cura on the left, very easy, or if you are using another program to slice and print, have a look through your settings. The raft is another option you may have used, however the raft builds up a lot more material underneath your entire object which is wasted. It can also be a good option though, especially if you are using a printer like the Up Plus 2 which does not have the option of printing a brim but will do a good job with a raft.

– 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.

20160628_4D Print

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

20160423_3D Print Enclosure

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.

20160423_3D Print PCB Case

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.

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