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

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Robot Picasso Kickstarter Final Week!

The final week of my very first Kickstarter campaign is now here, and to celebrate I’ve put together a brand new video demonstration of what Robot Picasso can do. This time, rather than using the Solidoodle 3D printer to draw on paper as in the first video, this demonstration shows how you can collaborate with Robot Picasso and use the digital DXF file of your custom artwork to import into software like Adobe Illustrator. From there anything’s possible, including using the design to laser cut into any material!

robot-picasso-laser-cut

It’s been an exciting roller coaster so far, and the hard work is yet to begin making and shipping all the artworks. It’s been challenging being overseas for nearly 2 weeks on a pre-booked holiday – I haven’t been able to spend as much time as I wanted promoting and creating regular updates for the campaign. However it was also quite eye-opening to realise just how much can be done with a laptop and internet connection – the video demonstration was completely created from my hotel in Hawaii, giving you an idea of how versatile Robot Picasso really is. You can receive your own custom DXF file for just $15 AUD, and have it included in the eBook compilation which all backers receive. Great if you are digital savvy and have access to some cool toys like plotters, laser cutters, routers etc.

Please help me to share this campaign on social media, it would be awesome to reach 50 backers over this final week (currently at 32) and increase the amount of artwork in the eBook. If you’re not into getting a custom drawing, you can buy the eBook for just $8 AUD and have it emailed to you after all drawings have been produced. See if you can figure out what each drawing is!

– Posted by James Novak

WTF, a low-poly goat?

20160322_3D Print Trophy

Yes, a low-poly goat. A few in fact.

These are 2 trophies that I’ve 3D printed for my second year class at Griffith University as awards for their current project designing lights for Yellow Goat. Nothing beats getting the students to work on real projects with industry, and adding an extra incentive with these trophies adds an extra competitive level and of course bragging rights for the winners! If you look back to one of the largest 3D printing projects I’ve tacked using desktop machines, the Mario Kart Trophy, you’ll see it’s not the first time I’ve used 3D printing to create a custom trophy. It’s turning out to be a great application of 3D printing since you can get really creative and produce them very cheaply (I wonder if trophy manufacturers are using 3D printing?). On the left is the trophy for the best design as picked by the team from Yellow Goat, and the trophy on the right is for the best team leader, chosen by averaging the marks of all team members and finding which team overall has the highest marks.

20160323_Rhino Low Poly

The 3D CAD modelling of this design was not as straight forward as most of the other designs on my website, so here is my workflow in case you’d like to try something similar (you don’t need the same software, just to understand the process):

  1. Trace the outline of the Yellow Goat logo (shown above right) in Adobe Illustrator. Export as a .dxf file, providing accurate 2D line-work to use in the 3D CAD model (you could just bring the image directly into your CAD software if you prefer).
  2. Import the .dxf file into Solidworks. Use this line-work to base your 3D modeling off. I also created some guide lines to ensure that my model would fit onto my desktop 3D printer without needing to scale later.
  3. Export the final model from Solidworks as a .IGS file.
  4. Import the .IGS file into Rhino. The model in the image above on the left is the imported model from Solidworks (yes you could just model the design in Rhino to begin with, however I knew I could get to this point much faster in Solidworks).
  5. Use the “Reduce Mesh” tool in Rhino to reduce the number of faces of the mesh. I reduced mine by about 93%, resulting in the low-poly model shown above. It’s also possible to do this type of low-poly conversion using the free software MeshLab, just click here to read one of my previous posts about how to do this.
  6. Because 93% is a huge reduction, the resulting mesh did have some gaps where the software didn’t know what to do, so was not watertight (manifold) and ready to 3D print. I manually cleaned up some of the edges and added some surfaces to fix this issue.
  7. Export as .stl and 3D print!

20160321_Yellow Goat

As you can see I still ended up splitting the large goat piece in order to minimise support material, printing the body piece upside down with the legs in the air and gluing the head back on later. It took a few prints to get the smaller goat right, the middle image above showing some of the messy surfaces I was getting from the Up! Plus 2 printer I used, surprising since it’s normally very good. The ABS seemed a little more sticky than normal as well, meaning the support material didn’t just peel away but had to be scraped and cut, making more of a mess. But third time lucky! I also downloaded the human figure from Thingiverse to again save some time, and it gives the effect I wanted anyway. A bit of chrome spray paint, a chipboard base and voila!

Check out the 3D model above for the full effect of the low-poly design!

– Posted by James Novak