Yes I Wrap, Don’t You?

20180831_3D Print Vase Wrap String

One of the common features of desktop 3D printing is the sharp, hard feel of plastic with that scratchy horizontal layered surface finish. Sure plastic has many benefits, but when you handle 3D prints all day long you sometimes forget that there are other textures in the world that are soft, delicate, pleasurable to touch. Enter the wrap, an experiment that softens those 3D prints in a crafty, hand-finished way.

For this project I downloaded the Customizable Twisted Polygon Vase from Thingiverse, which you will notice when you download is a solid block. This print takes advantage of a feature known as “vase mode” in many slicing programs, although if like me you are using Cura it’s called “Spiralize,” and you will need to activate it in your settings in order to have it available in your main screen settings. Basically the idea is that you can load any solid 3D model and automatically turn it into a vase-like shape i.e. a base and an outside wall without any interior or top surface. The outer wall is a single perimeter, which the printer continually extrudes in a spiralling/helical fashion as it works its way up the vertical height of your object. So no need to use a “shell” command in your 3D CAD modelling software, you can design a solid block and let the slicing software automatically create a single perimeter based on the extruder settings of any FDM 3D printer. A fun project in itself.

Phase 2 of the project was to use some wool yarn to wrap the exterior. What’s interesting about this process is that the layered surface finish of the 3D print actually helps hold the yarn/string in place, stopping it from slipping down the vase and helping align each rotation of the yarn. A relaxing project while you’re sitting in front of the TV or Netflix! The yarn I used was very fine so took quite a while, however you could easily use a thicker yarn to reduce the amount of effort to achieve a similar result. The result is really interesting; it keeps the layered appearance of a 3D print, yet is soft to the touch and provides a unique finish to the vase. Something you could easily customise with colours and different types of yarn materials. Ultimately, it creates an interesting combination of a highly digital process with a more craft-based process and material… Something worth a bit more experimentation I think.

If you give it a go, please share a photo with me, I’d be interested to see your results!

– Posted by James Novak

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A 3D Printing Workflow with Free Software

Solid Hollow Lattice

One of the challenges for designers (beginner and advanced) creating objects for 3D printing is finding software capable of doing the complex things we enjoy seeing in 3D printing news and exhibitions. There really doesn’t seem to be one program capable of doing it all, and this has been re-emphasised to me during my recent studies at MIT and a visit to Autodesk. However, there is some good news: if you’re able to quickly learn software, you can find an increasing number of freebies that seem to be specialising in small aspects of the workflow, which you can move between to create complex designs.

Form 2 Print Lattice

This tutorial will show you how I used completely free software to create a complex object during my time in the MIT course “Additive Manufacturing: From 3D Printing to the Factory Floor” as part of a group project, and is actually very quick once you become familiar with the programs. This particular design combines a hollow object with an internal lattice structure suitable for SLA printing on a printer like the Form 2 from Formlabs, which is what was used for the translucent version in the photo above. The white version in the background is a cross-section view of what is going on within the SLA print.

Step 1: The Overall Form

Clip 01 - 01

There are loads of free programs to use for creating 3D models – Tinkercad, Sketchup, Openscad, Sculptris, Fusion 360 (if you’re linked to an educational institution)… there are many more and you can certainly use your favourite. For this project, I actually used Onshape for the first time, which runs completely in the cloud (so no software downloading or limitations on computer operating systems/specifications). If you are at a school or university, you can get a free license. It works very similar to Solidworks or other high-end CAD packages, so if you are familiar with sketches and features, you will pick it up very quickly.

Basically, whichever CAD software you use, you want to create the overall shape of your object. In this case, I created an organic tear-drop shape using a “loft,” and cut a section out of the back so that it would clip onto a desk and act as a bag hook (part of the MIT design challenge).

Step 2: Make it Hollow

Many CAD programs will allow you to “shell” your design, making it hollow inside. However, if you can’t find the tool, or aren’t getting good results, we can do this in the next piece of software. But first, export your solid file as a STL (and if you managed to shell it in this step, export a STL of the hollow version as well and skip the rest of this step. You will still need a solid version for the lattice process).

Meshmixer Hollow

The next free program, which I think is a must for anyone with a 3D printer, is Meshmixer. It allows you to edit the normally un-editable STL file format, and I have previously written tutorials about how to do download files from Thingiverse and combine them in creative ways or add your name to a downloaded part.

If you weren’t able to hollow out your design previously, click on Edit>Hollow and set your wall thickness. Just like that, your solid object is now hollow, and can be exported as a STL.

A note for SLA printing:

Meshmixer Drainage Holes

When using the Form 2 3D printer for the first time, I was surprised to learn that the PreForm software doesn’t allow for the user to specify infill patterns in the same way that is commonly done with FDM printing. That is what created the need for this custom lattice infill, and this tutorial. So, being a liquid resin printer, the final important step is to add drainage holes so that the form doesn’t end up completely full of liquid, and errors don’t occur during printing.

Meshmixer again has this function built in. While in the Hollow tool, you will have the option to “Generate Holes” and manipulate their location. This is really important, as you won’t be able to do it again later once your hollow and lattice are combined (unless you’re familiar with the boolean commands in Meshmixer and manually add a cylinder from the Meshmixer menu to use as a cutting tool).

Step 3: Creating a Lattice

Lattices and 3D printing are best friends. But creating a lattice in many CAD programs is close to impossible, usually requiring advanced skills and a computer that can handle very large patterning features. nTopology Element is a free program that will dramatically simplify the process for you – simply load a STL file, choose a lattice pattern, and boom! your object is now a lattice. But let’s go through it a little more slowly.

1. Import your solid STL file into nTopology Element.

2. On the top menu, click Lattice>Generate

3. In the pop-up, you can play with the lattice patterns (called “Rules”), the size of each lattice volume, and click Generate to get a preview. When you’re happy with the result, click on Apply.

nTopology Lattice Trim

4. You will notice that the result has the lattice coming outside of the original object. This is because only whole lattice volumes are used to fill the object, rather than automatically being trimmed to fit. So we must do this manually. In the top Edit menu, click on the Trim tool. A new pop-up will appear, asking you to select the Lattice geometry and the Trim Volume (original model), which you can select from the drop-down menu on the left. Click apply and the lattice will be trimmed to fit perfectly within your original design.

5. At this point, the lattice is made up of vectors – they have no volume. So the next step is to use the Thicken tool on the top menu to provide a diameter to your lattice.

nTopology Tutorial

6. Lastly, the thickened lattice needs to be turned into a single mesh that can be 3D printed. The Mesh button (where it says Interchange on the top menu) will join everything together and give you a single mesh. In the drop-down menu on the left, you can now right-click on the mesh, and click on export to get your STL file.

Step 4: Bringing it all Together

The free version of nTopology won’t let you stitch multiple files together, however the Pro version will if you ever end up with the need for a full license. So back to Meshmixer to bring it all together ready for 3D printing.

1. Import the hollow STL and lattice STL into Meshmixer (when you click on import for the second file, use the Append option).

2. You will notice that the ends of the lattice stick out from your object. There are 2 ways to correct this: Option 1 is to use the sculpt tool with the “Flatten” brush to go around and push the ends of the lattice inside of the object boundary – it’s just like pushing clay.

Meshmixer Sculpt Lattice

Option 2 is to ever so slightly reduce the scale of your lattice. With the lattice selected in the pop-up Object Browser window (on the right of my window), click on Edit>Transform and you can either manually manipulate the scale, or more accurately type in the reduction in the transform window (with the uniform scaling option ticked). You should only need a small reduction until the lattice fits just inside the outer skin of your object.

3. By turning off the hollow part in the Object Browser, but keeping it selected, you will get an X-Ray view into your object to check if the lattice and hollow part are intersecting. This can help with any final alignment. Remember; you want the lattice touching the solid shell, but not poking through so it’s visible, or loosely floating within the hollow.

Meshmixer Lattice View

4. In the Object Browser, [shift]+click to select both parts at the same time. A new window will appear that will allow you to Boolean Union or Combine both parts together, creating a single object.

5. Export the final STL and you are ready for 3D printing.

SLA Form 2 Print Fresh

Step 5: Getting Creative

Meshmixer Creative Lattice

Once you get a bit of experience with this process and some of the other tools in Meshmixer, your imagination is the limit! You can really begin to play with different combinations of solid and lattice structures depending on the result you want. Have some fun and feel free to share any of your own creations in the comments section.

– Posted by James Novak

3D Printed Hooks

20180521_3D Print Hook

3D printing really does solve so many problems – previously I’ve replaced a small whisk in a milk frother, produced my own kitesurfing fins, 3D printed locking mechanisms for some stand up paddles, and made numerous enclosures for Arduinos. What did we do before 3D printing?

This is yet another example of the need for a unique part – some hooks to display some work in front of my office, which could attach to some vertical plywood fins without permanent fixings like screws or staples. The plywood is 17mm thick, which was the only dimension needed to create this hook design, and I’ve modelled the arms to be a maximum of 17mm apart, with a 1º draft angle to really hold on to the plywood towards the back of the arms which are less than 17mm apart. This creates a good clamping force on the plywood. They are also designed so that they require no support material when 3D printing, making them fast and efficient to produce.

While it’s quite a unique case, I’ve decided to share the design on Thingiverse, Pinshape and Cults  in case it’s of use to anyone, or even just a good starting point for your own design. You could even try scaling them in width to fit the dimension of your vertical board. Happy printing.

– 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

Ninjaflex Part 3 – Flexion Extruder Upgrade

20180515_Flexion Wanhao

This is the third post in a series about 3D printing with Ninjaflex, which initially began using the stock standard extruder on a Wanhao Duplicator i3 (click here to start at the beginning), before a 3D printed modification was trialled (click here for post 2), and now here we are with a completely upgraded extruder specifically for printing with soft materials.

Pictured above you can see some fancy red anodised components and exposed gears – this is the Flexion HT Extruder, a relatively expensive upgrade (US$179) which is about half the cost of the entire printer itself. It replaces the entire core of a standard single extruder; all that remains from the original is the stepper motor and cooling fans. So why upgrade?

Well as the previous posts discovered, the highly flexible nature of Ninjaflex (shore hardness of 85A) meant that it was difficult for the standard extruder to force down through the hotend and out the nozzle. Imagine taking a length of soft liquorice and trying to push it through a hole that is smaller than the liquorice diameter! As a result, after a few minutes of printing, it was common for the filament to begin looping out the back of the extruder. The Flexion extruder has much tighter tolerances around the filament the entire length it travels, so there is nowhere for the filament to go except down. Also, it has adjustable pressure using the round dial you can see with the knurled detail in the photo above – this means you can apply more force on the soft filament to maintain a strong grip against the stepper motor gear. By rotating the dial, you can quickly scale the pressure back when you change to a rigid filament like PLA, with 4 levels of variation possible and a grub screw to really dial in each setting. The design is completely open, (when it was assembled I initially thought something was missing!), which means you can see the filament and gears, which is great for maintenance and adjustment. And while I haven’t tried yet, according to the Flexion website the nozzle can handle higher temperatures than a standard extruder, up to 290°C, which is great for plastics like nylon and polycarbonate.

The photo at the top right is one of the first 3D prints done to test the abilities of the extruder, taking approximately 4 hours. It looks good from a distance, although there are some small gaps where we started with too much retraction and not enough flow – at this point we are still experimenting with settings to get the best results, currently trying 107% flow, 40mm/s print speed and 1mm retraction. If you are using a Flexion for Ninjaflex and have some reliable settings, I’d love you to post a comment and share them!

– Posted by James Novak

3D Printed Assemblies

20180420_3D Print Moving Assembly

One of the most interesting features of 3D printing is that it’s possible to print multiple parts in their assembled state, reducing the need to bring together a whole range of different pieces and assemble them using screws, snaps, glue etc. While this is normally easier using the Selective Laser Sintering (SLS) process, with a bit of experience and some clever design skills, it’s possible to 3D print moving assemblies on a basic desktop FDM machine.

Pictured above are 2 objects I’ve been wanting to 3D print for a long time as great examples of what can be done with an FDM machine. The first is called an Air Spinner and is free to download from Thingiverse. Due to the tolerances and angles between each part, no support material is needed, and you can literally start spinning each of the pieces straight off the printer, functioning like a gyroscope. A nice quick print, and a great demo piece. Below is a video I found of someone printing and spinning one so you can get the full effect.

The second print pictured to the right is a Planetary Gear Keychain, also free to download from Thingiverse. This one is much more of a test of your printer’s settings, the first time I printed it all of the pieces were completely fused together and impossible to free. Even this print required a knife to separate pieces that formed part of the first layer, with the squished plastic bonding them together as my nozzle was slightly too close to the print plate. This one is remixed from another design on Thingiverse which I recommend you check out for all the instructions to help get the best result, and read how other people achieved successful prints. Here’s a short video to see the planetary gears in action

If you’re looking for some fun prints to share with people, these 2 are very much recommended and relatively quick, although I’m still a very big fan of the Kobayashi fidget cube from one of my previous posts whichis another great assembled object. If you’ve got a favourite 3D printable assembly, leave me a comment/link below and I might add it to my list of things to make!

– Posted by James Novak

Ninjaflex Extruder Mod – Fail

20180409_Ninjaflex Mod

This is a short little update following on from my last post attempting to 3D print with Ninjaflex filament (soft TPU):

After limited success using the stock extruder on a Wanhao Duplicator i3, I found a 3D printable Extruder Drive Block on Thingiverse to supposedly help stop the filament from finding its way out out the back rather than being forced down into the nozzle. Well, as you can see from the photos, it looks like it fits quite well, although I did have to slice and file a few areas to fit properly – most notably around the shaft of the stepper motor which was far too tight and stopped it from turning, and the wheel that pushes the filament against the stepper gear which was blocked from putting any force against the filament so did not drive it down into the nozzle. Admittedly, the file on Thingiverse was designed for the Duplicator 4, so it was a bit of a long shot to work with the i3.

So back to the drawing board I’m afraid for Ninjaflex printing – perhaps time to upgrade to a Flexion extruder, or look at some other TPU materials that might be slightly stiffer and more suitable for this basic extruder. Flexible PLA looks interesting. If you’ve had any successes 3D printing with Ninjaflex on a printer like the Duplicator i3, leave me a comment 🙂

– Posted by James Novak

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

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