Building the RepRap Prusa i3 3D printer

A couple of weeks ago I attended Open 3D Engineering‘s first ‘Build Your Own 3D Printer’ workshop at Fab Lab Berlin to find out a little more about the process of 3D printing in general and the RepRap project in particular. I didn’t have the money nor the need to actually make my own printer, but there are a handful of things I would like to 3D print, so I thought it would be a great opportunity to learn more. While the 11 participants were untangling cables and programming microcontrollers, I was sticking a camera in their faces and asking stupid questions, mostly along the lines of ‘what does this button do?’ or ‘is that meant to snap in two like that?’

Occasionally I did actually get some hands-on experience, wielding big dangerous tools like hex keys or tweezers, but mostly I was there to watch and learn. I am currently building a machine of my very own though. As I said, personally I don’t have much interest in owning my own 3D printer just yet, but something slightly more suited to my lifestyle is a programmable open hardware camera slider. There’s also only one axis to worry about…

So I’m starting to put it together and 3D printing the custom parts with Bram, I’ll keep you posted – hopefully there will be some nice fluid time-lapse / stop motion / motion-controlled video footage in the next few months.

just waiting on a few more parts…


In the meantime, here are a few thoughts, theories and questions on the RepRap project:

To me, and many others, what is truly fascinating about RepRap is not just the sci-fi nature of converting bits to atoms. It’s not even the decentralised open source collaboration of the project. It’s the process of evolution in action and the exponential growth which can only come from a self-replicating machine.

To understand the thoughts behind the project, read Adrian Bowyer’s ‘Wealth Without Money‘, a short manifesto of sorts originally published in 2004, which lead to Bowyer creating the first RepRap printer in 2008.

In addition to founding RepRap, Adrian Bowyer’s other great life achievement has been making it into the 2013 Open Source Swimsuit Calendar


Further reading on a different aspect of the RepRap project: developer Erik De Bruijn’s Master’s thesis “On the viability of the open source development model for the design of physical objects – Lessons learned from the RepRap project“[pdf]

You might wonder how anyone has time to develop 3D printers and earn a living at the same time – contributors aren’t paid to improve RepRap machines, and as the designs are open source, nobody can claim a commerical monopoly on their designs. So how do they make a buck? Is Adrian Bowyer flipping burgers part-time?

There’s no commercial company pulling the strings behind RepRap, although many of the people deeply invoved in the project have ended up using their expertise to start their own companies or otherwise work professionally around the project, providing an interesting look at the business models which arise without a commercial monopoly.

Adrian Bowyer’s company RepRap Pro, for example, makes and sells RepRap kits and provides training in 3D printing, benefiting from his experience and status within the RepRap community. Josef Prusa, designer and namesake of the Prusa i3 we were building, has written a book called  ‘Getting Started with RepRap‘ in addition to running workshops and offering 3D printing consulting. Erik De Bruijn’s commercial project, the Ultimaker 3D printer, is one of the most popular domestic 3D printers and was recently rated ‘Most Accurate’, ‘Fastest’, and ‘Best Open Hardware’ in Make Magazine’s in-depth test of 15 3D printers. There’s also a growing ecosystem of parts, electronics and filament supply specialists around the project.

One interesting point in de Bruijn’s paper is that the RepRap community is doubling in size every 6 months (or was, in 2010 – have any further surveys been made?). It made me wonder about the diversity of people getting involved. In his survey de Bruijn looked into demographics based on education, age and background, but one thing you may notice from the workshop video is that all participants were male. I’ve tried to find information on the level of participation by women in RepRap or 3D printing, but haven’t come across much. RepRap is basically at the intersection of two very male-dominated fields, mechanical engineering and free software, so perhaps it’s not surprising that (to an outsider, anyway) there isn’t much visibility of women in the project. Are there many high-profile women in this area? Has there been much discussion of the subject? Got any links to articles?

Siri, Print Me A Chair


This post originally appeared on my blog at

In the future, should we ever bore of our jetpacks and decide to come back down to earth, sit at the hovertable and eat our 3D-printed bacon and eggs, we’ll need something to sit on. With today’s open design tools, it seems the future of furniture is already upon us (or are we upon it?). When you combine 3D software with digital fabrication equipment like CNC mills and laser cutters, you’re just a few mouse clicks and the push of a button away from your own quasi-futuristic space furniture. That’s the theory, anyway. This week I’ve been experimenting with creating my own open source chairs and there’s a little more to it than just hitting Ctrl+P.

I’ve been using a simple free software program called SketchChair which avoids some of the usual complications of computer aided design (CAD).

3D CAD software is often expensive, and difficult for beginners – there can be quite a learning curve just to make a simple mock-up. When trying to make a physical object like a chair there’s even more to think about – how much weight can your design handle? How about joining your parts together – do you know your dovetail from your dado? What materials and construction techniques will you use? Will you mill it from solid wood, or slot it together from lasercut 2D sections?

Even once you’ve designed a 3D model with all this in mind, you need to communicate this design to your fabrication machine in a way it understands – with the right settings and file formats. Then comes prototyping, testing and adjustment. And I’m assuming you’re doing all this work without anything to sit on.

One way to reduce this confusion is to use a simplified, very specialized tool which can be as basic or as in-depth as the user requires. SketchChair, for example, has one main function: it allows you to design a chair in 3 dimensions, and have it ready to be cut out in minutes. But allow plenty more time for tinkering…

You draw your chair in profile, and the software instantly adapts it with perpendicular slats, turning your quick doodle into a digital blueprint of pieces which can be cut from a flat sheet and slotted together in a 3D form.

It solves many of the usual CAD issues simply by making decisions for the user. You can go deeper and fiddle with details and settings, but the standard settings allow the user to focus on their design without getting stuck on joints and angle calculations.

One unexpected problem I had wasn’t a software issue – it was inspiration. Most people don’t spend their lives fretting about the angle of a chair’s back – sometimes you don’t know what you want until you see it in front of you, in context. I’m no chair expert, and once I started drawing, I realised that my ‘original ideas’ were all just sad copies of the Panton or Barcelona chair….

Not all my designs worked out so well for my poor test subject

Not all my designs worked out so well for my poor test subject

It took a day or two, but I got there in the end – making a chair with SketchChair is indeed much faster than learning joinery and manufacturing by hand, but it’s not quite instant.

First of all, it’s beta software – it’s still buggy and best left to the intrepid, or at least, the very patient. It takes time to explore and understand the scope of what can and can’t be achieved.

To make a physical model you can test out your prototype with cardboard and scissors, but a full-size wooden version is trickier. I don’t have a laser cutter or CNC mill, so the choice is either sending the design files to a manufacturing service like Ponoko or Shapeways (takes a few weeks) or hunting down someone in your local area who can make the chair for you. Depending on where you are, it might take a while to find someone – try 100k Garages or a FabLab – but you’ll meet a friendly local and it should be done in an afternoon.

I found a CNC guru down at Open Design City, my local makerspace. We still haven’t found time to cut the chair out, but hopefully I’ll be sitting on my very own SketchChair in a week or two. I guess that’s one of the issues with dealing with people rather than factories – they still have to eat, work and sleep. Once I figure out how to upload my design to the SketchChair design library, it’ll be available for anyone to download, adapt or improve, under an open source license.

At this stage SketchChair users can only ‘like’ a design in the online library, but in the future I can see something more akin to the Thingiverse model, which is an online repository of designs, mostly for 3D printing.

Thingiverse has an active community of users posting designs under open licenses, commenting, rating, reviewing and offering suggestions, and has grown into a supportive digital fabrication community. When people remix designs, they link back to the original. The site serves as inspiration, a place to learn, and a channel for feedback.

As you browse a repository of designs you also begin to understand the capabilities of a manufacturing technique and just what can be achieved – in SketchChair’s case, the bowls and tables created with the software show you a much broader range of possibilities than the name implies.

IKEA’s not going to be toppled any time soon, but if personal design and digital fabrication is going to become a bigger part our lives, it’s online communities like Thingiverse and specialized tools like SketchChair which will enable beginners to get the most out of their ideas. I think we’ll see many more examples in the coming years – SketchChair is a great start, but why not SketchHouse? SketchBike? SketchShoe?