3D Printed Knits

191115 3D Print Knit

Did you know it’s possible to knit using a desktop 3D printer?

This has been some work I’ve been doing in the background for a little while now and combines all the benefits of digital design with craft-based hand assembly. OK, so you can’t print with soft yarn (yet), but by printing thin geometry you can create some relatively soft and flexible knits that are unlike the typical chainmail assemblies often used in 3D printed fashion/textiles.

The trick to this is to simplify the knit into individual pieces, which can be 3D printed flat on the build plate. This makes printing extremely fast, also known as a 2.5D print which I’ve written about in a previous blog post. While one of the benefits often discussed about 3D printing is the ability to produce complex assemblies as a single part, in the case of a knit, this will result in significant amounts of support material, and the need for quite bulky geometry to ensure the knit geometry is strong enough. However, by printing separate components, these problems are avoided, and you can have some fun manually connecting the loops together while you wait for the next print.

Additionally, the new opportunity of 3D printed knits is to create completely new patterns and geometries in CAD software. This has been the focus of my newly published paper called A Boolean Method to Model Knit Geometries with Conditional Logic for Additive Manufacturing (free to access). In it I detail how to set up an algorithm in Rhino with  Grasshopper that will allow customisation of loop and float structures for a knit, the sort shown in the top picture. If you have some experience with the software, you can follow the process outlined in the paper to set up a similar system, and begin modifying parameters and geometry to create completely new knits that would not be possible using traditional knitting techniques.

191115 Grasshopper 3D Knit

As shown above, the Grasshopper code gets quite complex so is not for the feint of heart, but if you understand boolean logic, and have used Grasshopper, I’m sure you can build this! And if not, have a go at modelling some knit geometry in your favourite CAD package and print it out – you can keep printing on repeat to extend the size of your “knitted” textile, this is how some of my early tests were done. If you start by modelling some rows of circles, then connect them together, this will get you close to a knit structure.

Happy 3D knitting.

– Posted by James Novak

Shim the 3D printed shim

IMG_20190226_3D Print Shim Doorstop

We’ve all experienced that wobbly table at a cafe and struggled to wedge coasters and napkins under the legs to balance it out. This is where you need a shim, a small wedge that can fill the gap and ensure your drinks don’t go flying. Shim is also fun to say, quick to 3D print, and a good test of your print settings due to the top surface exhibiting the stair-stepped effect.

There are many designs available on popular 3D printing file websites, but I just wanted one that was a useful size (easy to carry with you in a small bag) and that said what it was. So here it is, Shim the shim! You can download it for free on Thingiverse, Pinshape, Cults or MyMiniFactory. Alternatively you can follow the basic outline of the design process below to make your own from scratch in your favourite CAD software. It’s similar to some of my previous designs including an “edditive” desk logo which might give you some inspiration for different ways to use text in 3D.

IMG_20190226_Solidworks TextShim was designed in Solidworks by using the text tool on the top sketch plane. The key is to squish all of the text together so that the letters intersect, meaning they will 3D print together as a single object (in Solidworks you can simply change the spacing of text within the text tool). The text was then extruded 10mm, creating solid geometry. All you need to do to create the wedge shape is then slice a triangular portion off the top, which in Solidworks uses the extruded cut tool. Save to STL and 3D print, it couldn’t be much simpler!

This is a nice quick 3D print and could easily be used as a keyring or give-away item, especially if you design your own. Enjoy, share and print!

– 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! 😉

– Posted by James Novak

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

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

Return of the Beer Bottle Lock

20170823 Beer Lock Blank

It’s been quite a few years since I first posted this design on my blog – check out where it all began here. One of the great things about sharing designs like this on file sharing websites like Thingiverse or Pinshape is that you get to see when someone enjoys your design and shares their own photos of the print, or even better, remixes it to add their own unique twist to the idea. Someone even made a video on Youtube which featured this lock 🙂

Occasionally I get requests, either on these websites, through social media, or on this blog, for me to make alterations to a design, or share the native design files for someone to more easily modify. 9 times out of 10 I’m more than happy to help. A few days ago I was contacted through Twitter to make a simple variation to my Beer Bottle Lock, removing the text on top that says “hands off my beer” to provide a blank surface for someone to more easily add their own custom text.

Given that the file is parametric in Solidworks, the alteration only took a few seconds. However rather than email the files direct, it seemed like a good opportunity to share a remix of my own design on Thingiverse, and hopefully benefit even more people. So you can now download this design for free by clicking here, just like the original.

This got me thinking about remixes, and the fact that many of my favourite 3D printing sites like Pinshape and Cults don’t really allow for remixes to be clearly linked to the original source file. I can either upload a print of a design (just photos, not a new STL file), or upload a completely new design. If I want to let people know this new design is a remix, I have to manually write this in the project description, and supply a URL to the original file as you can see on my upload of this new blank version beer bottle lock on Pinshape. On Thingiverse, you can specifically say your design is a remix of another with the click of a button, and a link is created so others can easily go to the original, and see all remixes to find the one most appropriate for them. This is a better system that ties in with the whole Creative Commons (CC) licencing used by all of these websites.

I hope some of these other file sharing websites will take up the challenge to make file attribution and remixing more transparent, it shouldn’t be left up to the user to understand the licensing options and manually enter this information. A common standard across a website, as done by Thingiverse, would really help encourage more sharing, and appropriate attribution to designers.

– Posted by James Novak

From Sketch to 3D Print

Sketch to 3D Print

Designing your own 3D printable object can be daunting if you’ve never used a 3D CAD program before. This is a challenge that one of my university classes is facing, with most of the students new to 3D design, but eager to begin experimenting with 3D printing. So this week we explored a workflow that allows them to take their hand-drawn sketches through a couple of simple processes, resulting in a 3D printable file, without having to model in 3D from scratch. So here it is just for you – follow along and let me know how you go.

Step 1: The Sketch

biro sketches

This is the easy part! Find a sketch that you’d like to turn 3D. It’s best if it’s drawn clearly in pen, so if your sketches are in pencil just trace over them on a fresh sheet of paper. For this example I’m borrowing a sketch from online. You must then digitise your sketch – best using a flatbed scanner, or take a photo in good lighting conditions so you get good contrast between your linework and paper.

Step 2: Vectorising

Illustrator Tracing

We are going to use Adobe Illustrator to automatically trace the outlines of our sketch. Place your sketch into a new document, and you will see a “Live Trace” or “Image Trace” button appear (depending on your version of Illustrator) near the top menu. You may find that one of the preset options will give you an accurate tracing, or you will need to get into the options and start tweaking the settings. I have an older version of Illustrator, but the settings that work for me are shown above. What you are looking to achieve is a good level of detail, and nice closed lines. Once you have a good result, you can use the “Expand” button to turn the result into individual lines that can be selected. You can also go to the menu and select Object>Ungroup so that your linework is no longer all grouped together as a single item.

Step 3: Exporting

Illustrator SVG

If you have a collection of sketches like this example, you will want to now Save your file (so you can come back to it and make changes later on), and then delete everything from the file that you don’t want to turn 3D. For this example, I have just left the flower tracing that was in the top-right corner. Go to File>Save As and save this drawing as a SVG file. This is a 2D drawing format that will be recognised by our 3D software.

Step 4: Going 3D

For this example we are going to use the freely available 3D software Tinkercad – one of the best features being that it runs from your internet browser, no need to download and install anything. I recommend it as a great place to start your 3D modelling journey, however if you’re already using a more advanced 3D CAD program you can still follow along with this tutorial – the process will be quite similar.

Tinkercad Import SVG

Create a new Tinkercad file, and at the top right of the workspace is the “Import” button – select your SVG file and it will automatically be turned into a 3D object as shown above. Depending on your sketch and requirements, this might be all you need to do and you can jump straight ahead to Step 7: Exporting. However I want to make some modifications to this design now that I have a good starting point in 3D.

Step 5: Modification

Tinkercad Cut

For my needs this object is too thick – I only want it to be 2mm tall. In the right panel of objects is a translucent box – this box is like a cutting tool, anywhere it touches my 3D object it can be used to cut away at it. Place a box in the middle of your 3D model, and use the Length and Width sliders to fully enclose your 3D model. Lastly, rotate your model to a side view and you will see an arrow pointing up or down – click-and-drag on this to move the box up 2mm above the workplane.

Now select both the 3D model and the box (either click-and-drag a selection box around the workplane or hold the Shift button and select both objects) and you will notice at the top right the Group icon becomes available. Click on this and Tinkercad will subtract the box from the 3D model, leaving just a 2mm thick object.

Step 6: Patterning

Tinkercad Pattern Duplicate

Rather than just printing one of this design, I want to create a more complex pattern. Firstly I need to scale the design down so that it’s a bit smaller. Do this by clicking on the object, holding the Shift button and using the corner handles to click-and-drag the object down in size – mine is about 40x40mm.

With my object selected, at the top left of the window are the standard Copy and Paste actions, as well as the Duplicate option – this is the option I use to make copies. It may copy the object in the exact same position as the original, so when you click Duplicate just click-and-drag this copy out into a new position. Repeat as many times as you like to create a pattern.

When you’re happy with the design, you will need to join all of these individual elements together into a single object. Similar to step 5, select all the objects together and the Group button will become active – however because all of these objects are solids, the Group function will join them together rather than cutting away.

Step 7: Exporting

When your design is complete, use the Export function at the top right of the window to download the object to your computer. The STL option is most likely what you will want for 3D printing. The STL format is the standard file type for all 3D printers.

Step 8: 3D Printing

Up Plus 2 Pattern

Finally you can load your STL into your 3D printing or slicing software and 3D print! If the print doesn’t give you the result you want you can either go back to the Tinkercad file and make some more modifications in 3D, or take a step further back to Illustrator and modify the original linework.

The process is not perfect or overly accurate, however for designs like fashion or simple experiments, this can be a good workflow to try if you’re better/faster at drawing by hand than modelling directly in 3D software. If anyone has some different workflows they enjoy using, please feel free to share them in the comments section 🙂

– Posted by James Novak

Turning a 3D Printer into a Plotter

20160304_robot-picasso

My last couple of posts have been about the Robot Picasso Kickstarter I’m currently running, a project that developed after the failure of the Solidoodle Press 3D printer. It’s attracted some media attention from 3dprint.com and Digital Trends who have followed up the saga of Solidoodle, the company going bankrupt because of the failings of this one printer.

Given the success of the Kickstarter, which is over 300% funded with a few days still to go, I thought it was about time to show the special 3D printed part that has converted the 3D printer into a 2D plotter. I developed the part in Solidworks using just a few key measurements, in particular the 2 front screw holes and the distance needed for the tip of the pen to lightly touch the plate where paper would be stuck. It sure beats using rubber bands and sticky tape which is how the initial experiments began! You can check out the 3D model below.

This is something that you could create for any 3D printer since most extruders have some sort of screw holes that you could take advantage of (for example you can see them in my Cocoon Create printer in this previous post), or perhaps you could design a clever snap-fitting system similar to the tutorial I wrote for Formlabs last year which shows the step-by-step process to designing a snap-fit enclosure. As long as you can create a secure fit, you will be able to get consistent results using your 3D printer as a 2D printer (plotter). If you want to see the process of drawing with this attachment, just check out the Kickstarter video I put together showing the full process of Robot Picasso. It’s a fun way to add a whole new function to your existing 3D printer if you can turn a 2D drawing into simple G-code commands.

– Posted by James Novak