From 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

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

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

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.

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

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

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

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

Tutorial – Perspective Grid

It’s a bit miserable outside and I thought I’d reflect back on the idea of tracing as a way to speed up and improve your sketching discussed in a previous post. When I went through first year Product Design our lecturer gave us piles of perspective grids to trace over – the exercises were completely boring, but the ‘cheat sheets’ have always been useful to stick under your drawing pad and make sure your perspective is relatively accurate.

In simple terms, you can draw your orthogonal views onto the ‘floor’ and ‘walls’ of the grid, then simply project them into the middle to generate the object. As you get more confident, you can skip a lot of the setup work and just draw your object using the grid lines as reference.

I have recreated one of these blank grids on an A3 sheet for you to download and use (although you can print it at any scale), along with a brief tutorial explaining how to go about using it. Please like or comment if this is any help to you!

Download PDF: 2 Point Perspective – A3sheet

Download PDF: Grid Tutorial

– Posted by James Novak

Ctrl+z – the most important rendering tool

It’s been a long time since I’ve had the chance to work on some quick and fun concept renders, and thought I’d briefly share the process I use. As mentioned in an earlier post, I like to make life simple where I can, so I start by doing a lot of quick sketches, then take the best ideas and trace over a template to ensure all concepts will be the same size. I use a few different felt-tips for the final linework, at least 2 different sizes (0.8mm and 0.2mm).

I then scan these into Photoshop, since I can’t survive without Ctrl+z! It’s then just a matter of building up layers, using my secret weapon (an old but still awesome media tablet). I’ve found this the best way to get that sketchy marker look, and simply erase the overflow. Once you get into the digital world, it can be hard to remember that concepts shouldn’t look finished – you don’t need perfectly smooth gradients like a CAD render (well, that’s my opinion anyway!). Save the big guns for later. A few shortcuts like ‘shift-clicking’ to erase or colour in straight lines are a must.

As everything comes together I like to add a layer over the top to add some highlights, and sometimes a layer for texture can help add another dimension – easy to download an image and overlay onto the sketch. Add in a background, or in this case a simple reflection of the product, and voila!

There’s a million different ways to present concept sketches, what’s your weapon of choice?

– Posted by James Novak

Cheating is Winning

I have to admit I’m not one of those designers who can spend endless hours with markers and pens putting my imagination onto paper. I’m a little jealous of people with that skill/patience. However there are times where it’s the best way to generate a lot of ideas, really quickly. But I still like to cheat!

To kick off a new project I’ve quickly drawn up a few different views of a wrist-band shape, which will allow me to trace the linework for my concepts – a really simple way to have a consistent look across all ideas.

And since I’m such a nice guy I’m letting you download the PDF for FREE! If you’re working on any wrist/arm/leg product it may just come in handy. Just click the link below.

Download ‘Band Template’

– Posted by James Novak

First Project, First Post

As the first post on this blog I thought I’d just jump straight in with what I’m working on right now. Being a kitesurfer I’ve been dying to find the time to try 3D printing some new parts to test out on the water. It begins today! I thought I’d start with the fins since they’re a nice manageable size for the small desktop printers at uni (starting with the ‘Up! Plus 2’).

The first tests will be similar to the original fin to compare how it holds up in the water compared to the original (Liquid Force GTS 2.0). Some of this will certainly come down to the print orientation to minimise the chances of de-laminating while skimming across the shallows and scraping the sand. I’m also thinking about using an acetone finish to help bind and smooth the outside surface when I get this printed in a few days. Some of my students have started trialling this with success, so worth considering.

If it works, the next step will be to experiment with the fin geometry. I’m definitely expecting some spectacular crashes on the water through this process, but that’s half the fun!

– Posted by James Novak