Review: 3D Printing with SketchUp (Packt)

Disclaimer: I received an offer from Packt Publishing to review the book “3D Printing with SketchUp”, written by Marcus Ritland. Packt Publishing is a print-on-demand service, from which I already bought several books, ebooks and for whom I also authored my Unity for Architectural Visualization book and the Building an Architectural Walkthrough with Unity video course.

I received this eBook version free of charge, but the review is solely my own, personal opinion.

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About 3D Printing

There has been a rise of attention to 3D printing, especially with more accessible printing facilities, such as Shapeways or i.Materialise (which is only 10 minutes by bike from where I work), but also with cheaper 3D printing hardware, that you can even order as a pre-assembled kit or to build from (almost) scratch.

On the other hand, where you needed to rely on more traditional CAD software, such as Rhinoceros, AutoCAD or MCAD software, most current CAD and even BIM software support the STL file format, which is the ubiquitous triangulated-mesh based format that 3D printers interpret. There is (almost) nothing special about the format: it contains points and triangles and, normally, contains a single volume.

The main purpose: having a clean mesh, with no overlapping faces, fully closed (water-tight) and with properly oriented normals. This is actually not that trivial with most modelling software.

In addition, due to physical limitations of the 3D printing process, there is a series of additional requirement for proper 3D printing, depending on the chosen hardware, such as having the need for support structures or a minimal element width/thickness for fine details. And the limitations of the maximum bounding box that can be printed.

The format itself is just a container of the mesh. The validity for 3D printing is left up to the STL writing software. Software such as Rhinoceros and 3ds max come with integrated Mesh Analysis tools that can discover a fair share of possible problems.

So what does this book offer?

Chapter 1 - concepts & process

The book is oriented to people with basic familiarity with SketchUp, but fairly new to the 3D Printing process. So the first chapter is not about SketchUp, but about the process. This is good, as even though the very basics of 3D Printing are easy to understand, applying them properly is quite tricky. The author links to his personal website for some instructional videos of the 3D printing process, which is recommended if you are new to this concept. Describing the process is one thing, but actually seeing a machine doing its work is totally different.

From the very first chapter, he hints at the complexities involved with 3D printing, by mentioning the need for printing a “support structure”. Although not all technologies have equal requirements, the fact is that you are working in layers and in most cases, these layers of materials rest on the underlying layer.

Especially in architecture, this is tricky, since a floor or roof is only supported at its edges, so it would need quite a lot of support material, which, depending again on the process, is costly.

From my own experience with our local Fab-Lab (in Leuven, Belgium), I remember such issues clearly with my students in their projects.

Here is an example of dark brown support structure, required for the helix shape:

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And here you see another example of a spherical shape, after its support structure has been dissolved. The metal box is used to protect the often brittle structures, while washing away the support structure. You still see a few dark spots on the sphere, and also the facets from the Mesh model.

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Strangely enough, pictures such as the ones I show above are completely missing in this chapter. Probably for space reasons, but it does help newcomers to make the constraints of the 3D printing process more understandable.

Luckily, the pitfalls are described, such as no mass-production advantages, lack of material choice and cost involved.

Chapter 2 - SketchUp for 3D printing.

At the end of the first chapter, it is clearly stated that this book opts for SketchUp for its accessibility, but also point out that it is not the best choice for organic, freeform design.

This book is NOT a SketchUp course, so you are referred to external resources for that.

So what does it cover then?

It briefly skims through downloading and installing SketchUp and gives an overview of the GUI. I’m not always convinced that this is required in such books. It is too superficial for newbies and there is no new information for existing users. However, it does help to state the used terms, so I understand why editors sometimes insist in keeping such overviews in the book. Here, they suggest to start from the 3D Printing template, which already contains a bounding box suitable for a Makerbot machine, but I suggest to look up what you need and create this box yourself. The advantage here is that the bounding box is a SketchUp dynamic component, which can be changed parametrically and they did included some presets for common 3D printers, so if your machine is included, make use of it.

Then he goes on to set up the interface and install some extensions, to better support 3D printing, most notably to support STL import and export.

And at page 25 the first actual SketchUp modelling exercise starts. Not too soon, but the background information that was discussed before is essential, most of the times.

Chapter 3 - from drawing to model

Here the book takes a more project-based approach, getting from a first sketch to a complete physical model. While this is didactically a good approach, the applicability to your particular case might be limited. The design is quite straight-forward: an extruded silhouette, which makes things much easier for 3D printing. But you have to start somewhere.

It discusses some nice workflow-aspects, such as modelling on top of a scanned hand-drawn sketch, using multiple object copies, to enable more design iterations (which would not be practical for a complete building).

On page 45, there is an interesting discussion on overhangs and when you should prepare for them in your model. This is exactly the kind of advice you would buy such a book for.

Chapter 4 - model resolution

Here, the use of curves and rounded surfaces that get segmented is discussed, which is very relevant in the context of translating the model into a physical object that you intend to make clean and smooth.

This is one of the most important chapters, discussing Wall thicknesses. It has a few shorter examples, talking about circle segments, the Follow Me tool and some tools from extensions.

All in all, this chapter could easily be double the size, when going more into detail about the actual process. And then it might leave some more room for additional pictures.

Chapter 5 - existing models

This is not my favourite chapter, as it is a bit about different model sites, although the example of the wrench goes into quite some detail.

Chapter 6 - Phone Cradle

This is a project-chapter again, although the subject might not appeal to everybody.

The author deliberately uses SketchUp MAKE and so has to do some additional work which the Solid Tools in the Pro version would solve more directly. But it does help you better understand the process of working with solids.

Chapter 7 - Coloured terrain

Here we convert a model from Google Earth into a physical terrain model for a colour-capable printer.

Chapter 8 - Architecture

This is not a book specifically about architecture, so most models are not scale-models, which presents an additional area of possible problems, such as walls or floors becoming too thin or details to small to properly print. This chapter answers some of these questions, although the chosen design might not really appeal to architects, at least those I am familiar with.

There are some interesting subjects, such as splitting up the model in parts, thinking about support structures. Here the approach is remodelling the reference model with new parts that are scaled properly for sufficient wall thickness. So you end up with a remodelled version of the initial design, specified for a particular scale and printer model.

Evaluation

This is a straight-forward, fairly practical book, written in a neutral but effective style. The reader is not dumbed down, yet the level is easily accessible for everybody with a basic SketchUp understanding. In fact, regardless of your level of expertise with the software, it is the insight into the ramification of modelling for 3D printing that is what matters most.

At 120 pages, including appendix and index, this is not a very long book. From my own experience of publishing with Packt, they seem to slowly focus more and more on shorter, specific books, not written by full-time authors, but by specialists. This focus and the printing-on-demand makes them quiet particular, as a publisher. There are much more niche-books in their catalog, in comparison with the multitude of Autodesk, Microsoft and Adobe oriented books from some other publishers. As such, the quality totally depends on the chosen author. This particular book is fine. It is practical, with sufficient detail and with a reasonably smooth learning slope.

I cannot comment on the print quality, as I only read the eBook, but this is fine, with the typical Packt layout. Lately, I started to be less resistant to eBooks, although reading front-to-cover for me still requires a paper book, sitting away from the computer.