Personal prototyping: 3D modelling (and printing) has come of age

  • Illustration by Kristina Collantes/Picture by Philip Friedman/Studio D
  • A 3D model of the Popular Mechanics paperweight, created in online modelling app Tinkercad
  • A sandstone rendering of the model
  • Autodesk Homestyler. Illustration by DOGO
Date:1 April 2012 Tags:, ,

If it’s good enough for Boeing, it’s good enough for you: 3D modelling (and printing) has come of age. – By John Herrman

There was nothing wrong with Stijn van der Linden’s screwdriver set, save for one thing: years of use had worn away identifying marks from the handles. Tired of fumbling through a pile of tools every time he needed a No 2 Phillips, Van der Linden sat down at his computer. Using a PC program called 3ds Max, he created a complete 3D model of a labelled, ordered case, custom-fitted for his old tools.

When he was finished, he sent the file to his desktop prototyper, or 3D printer. About an hour later his tool case materialised in white ABS plastic. Everything fitted perfectly.

Van der Linden, an electrical engineer by training, is admittedly not a beginner: 3ds Max is a professional 3D tool used to create, among other things, computer graphics for Hollywood films such as Iron Man and Avatar, and his 3D printer, the pp3dp Up, retails in the US for nearly R20 000.

Nonetheless, he says, the appeal of DIY 3D modelling and printing is universal. “You’re losing a lot of the limitations in the physical world,” he says. “For my whole life, I always wanted to make stuff. Now I can make anything I want.” It’s true: an influx of easy-to-use software and on-demand printing services has made it possible for DIY-minded individuals ““ not just professional engineers ““ to render their designs, be they brand-new inventions or just hard-to-find replacement parts, in 3D and have them printed in plastic, glass or even metal. Here’s how to get started.

3D for the masses
When most people think of 3D modelling, they think of CAD (short for computeraided design). CAD conjures images of engineers toiling over green-on-black wireframes. This perception isn’t entirely unfounded; 3D CAD modelling of the advanced, inscrutable sort has changed what it means to be an engineer and revolutionised everything from toy design to aviation. It has also been, until recently, almost completely inaccessible to ordinary civilians.

Today, though, 3D modelling has quietly opened to the mainstream. Free or affordable tools have emerged that are designed with ordinary people in mind. More importantly, these tools have found real, practical roles. Some, like traditional CAD programs, help people – tinkerers, inventors, artists – visualise objects in three dimensions. Others simply help you plan a new room in your home or reconfigure an old one.

Getting started
The biggest hurdle for would-be 3D-modellers isn’t the price or the complexity of the software – it’s the overabundance of options. There are pro-level modelling and rendering suites, finicky engineering tools, and simplified-to-the-point-of-uselessness art apps. In search of an entry point, I found an app called Tinkercad.

This free application runs inside a Web browser on nearly any PC or Mac and contains just the right level of functionality – it’s capable enough for real 3D modelling, but not so complex as to put you off. It’s a solid-modelling program – much like most professional CAD apps – which means that its models are an agglomeration of points in space rather than a hollow group of stitched-together polygons. With its emphasis on solid, volumetric materials, this type of modelling is particularly well suited for 3D printing, and Tinkercad has a button that creates a 3D-printer-ready file instantly.

To get started with Tinkercad, navigate to and create a free user account. I was presented with a blank slate – or, in the parlance of 3D modelling, an open work plane. Building in Tinkercad is conceptually simple: in the Add mode, you select a shape – a box, a pyramid, a cone or a cylinder – along with a size. You then stamp this shape into 3D space; clicking and dragging will stretch the shape as far as you want. The Sub (for “subtract”) mode lets you use the same shapes for object removal. One of the easiest practical projects is a shirt button: with the Add tool, stamp a disc that’s 16 mm wide and 2 mm thick. With the Sub tool set at 3 mm wide and 2 mm thick, stamp out two buttonholes near the centre of the disc. That’s it.

My first non-button project was admittedly a modest one: a Popular Mechanics paperweight. It was to be about 100 mm wide, with a thick, 25 mm-deep base. Our trademark PM lettering would be perched on top. (Swap for your initials if you want to follow along.)

Modelling a shirt button takes about 2 minutes; my paperweight took a great deal longer – about an hour, including 15 minutes to get used to the app and no small amount of trial and error. Getting used to the stamp-and-cut behaviour of the program was the biggest challenge; in its current incarnation, there’s no way to move or resize an object – a block, for example – after it’s been placed on the grid. Getting the spacing of the letters right took a few tries.

The core of the paperweight was composed of just seven shapes: one block for the base, four blocks for the M, and one block and a disc for the P. After creating the core, it was a matter of cutting, trimming, and adding accents. I subtracted small pieces of material from the middle of the M to match our iconic typography and carved out a hole for the P. I used small cubes to stamp serifs onto the letters and did cleanup with a 1 x 1-mm subtract tool. The end result was good enough. The next step was to make the paperweight real.

3D printing
Popular Mechanics has devoted a fair number of pages in the past few years to a company called MakerBot, whose 3D printers can create small, plastic prototypes in just a few minutes – all they need is a healthy supply of ABS plastic and a 3D-model template from a program such as Tinkercad. MakerBot’s machines are affordable, but only relatively: at upwards of R7 000, they’re far cheaper than industrial prototyping machines, but out of reach for most hobbyists – including me. Plus, I was making a paperweight, and MakerBots print only in plastic. I wanted something with heft – glass or stone or even metal.

Fortunately for me, I’m situated in the
US, where you’ll find Shapeways, an on-demand 3D printing service. Sending my model to Shapeways was a two-step process: from Tinkercad I exported my project as an STL file, the industry standard for 3D printing; at I just clicked the Upload button on the front page. Ten minutes later, I got a message saying that my model had been approved, and I was presented with nearly 20 choices of materials. For R190, I could have the project printed in ceramic. For R7 000, I could have it cast in sterling silver. I made my selection (sandstone, R270) and I would have my paperweight within two weeks.

I’ve already chosen a follow-up project: ever the picky tech editor, I’m custom-designing a case for my smartphone.

(There is nothing as comprehensive as Shapeways in South Africa, in terms of the number of technologies in a one-stop operation. Institutions such as Vaal University of Technology and a host of OEM representatives/service providers do exist, though, basically offering all major the technologies available. Particularly worth mentioning is the Idea 2 Product lab initiative started at VUT, and which is in the process of being rolled out. This will possibly be the closest to the Shapeways model, at a competitive price.)

Advanced prototyping
Software for 3D modelling ranges in price from free to thousands of rand and varies hugely in complexity. Tinkercad is a fantastic starting point, but you’ll hear a lot of other names when you dive into the world of 3D modelling.

SketchUp, by Google, is a popular program by virtue of its tie-in with the company’s 3D-mapping program, Google Earth. (Google encourages users to populate its virtual maps with 3D replicas of real buildings.) Blender, another free program, is an opensource alternative to professional programs such as 3ds Max. It’s versatile – there’s really nothing you can’t do in Blender – but it has a steep learning curve.

The app 123D, new from Autodesk, the company that makes the industry-standard professional CAD software, is a well-balanced tool kit for intermediate 3D modellers. Once you’re comfortable in a program such as Tinkercad, you can find your way in 123D.

“Three-D modelling started as a hobby,” says Van der Linden, but after launching a product line that includes kinetic toys, geometric sculpture, jewellery and desk lamps, it’s quickly becoming a healthy source of income.

Roman Vasyliev, a freelance designer, had been building model cars and planes for years before discovering 3D printing. His obsessively detailed World War I-era aircraft models now net a steady stream of income. (The top seller is a 1:44-scale model of the Caudron G.4, a French biplane bomber.) “I was really surprised that 3D modelling has become another branch of my hobby,” he says, “and now, my work.”

Modelling and printing in 3D has everyday applications, too. In an hour or two, Tinkercad or 123D can help you replace that once-irreplaceable knob on your priceless old guitar amp, for example. Last year a man named Duann Scott asked the manufacturer of his high-end baby stroller, Bugaboo, for a part to repair a broken hub lock. When the company said it would charge the equivalent of R2 000, he scoffed. Scott took apart the hub, figured out what he needed, modelled the parts on his own, and had them printed in stainless steel. Total cost: R100.

Bits and Atoms
A 3D model of the Popular Mechanics paperweight, created in the online modelling app Tinkercad.
File si ze: 348 kilobytes

A sandstone rendering of the model.
Object mass : 65 g

Home improvement
3D re-modelling
Half CAD tool, half video game, Autodesk Homestyler ( lets you visualise homeimprovement plans in 3D. Virtual rooms can be furnished with products from companies including Kohler, KitchenAid and DuPont. You can then explore the finished room in real-time 3D, or export it as a photorealistic rendering.

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