Adrian Bowyer interview, Computerworld

Here is the start of the four-page interview. Much of this is stuff that's been published before. Two parts I found interesting appeared on the third page.

Are there plans to modify the current design to replace non-reproducible parts such as bolts with parts that can be manufactured on the machine itself, bringing the overall RepRap design closer to 100 per cent self-reproduction?

Yes - that is definitely one of the evolutionary paths to greater reproductive success. For the immediate future I will be concentrating on widening the list of materials that RepRap can build with (starting with electrical conductors). That widening will implicitly raise the proportion of parts that it can make for itself, of course.

The Fab@Home people have already done a few embedded circuits by printing with conductive silicone. Making circuitry will be a very important ability for these machines.

Can the RepRap recycle what it manufactures?

Yes, recycling has been built in from the start... The main plastic we are using is polylactic acid...

But I want to move to using a non-biodegradable resin. This too is sourced from biomass, but is stable in the ground. That means that the more reprapped goods that get made from it and thrown in landfill, the more carbon is taken out of the atmosphere and locked away for good. And, in 200 years when we have taken so much carbon out of the air to make stuff that anthropogenic global cooling is starting to be a problem, the landfill sites become our strip coal mines to save us.

This is the first time I've ever heard anybody advocate for putting stuff INTO landfills as an environmental measure. An interesting approach to carbon sequestration.

RepRap is now half-way to replication

Vik Olliver has made good progress (1, 2, 3) on the goal of self-replication for the RepRap, having now been able to use a RepRap to fabricate half the RepRap's parts.

It's interesting that you can see the size of the volume pixels Vik is working with. These pieces were printed with polylactic acid, I believe.

Unrelated but cool: Kovio is a non-hobbyist company working on a process to inexpensively print working transistors. Early applications will include smart cards, later you'll see wall-sized displays.


Also unrelated but also cool: Fernando Muñiz has been working with UV-cured resins. This will work a bit like the CandyFab, except the uncured resin is still a liquid so under-support structures are still required. Interesting, I'm not sure if it's better or worse than the FDM approach used by RepRap, Fab@Home, and Tommelise. Also, I don't have any idea how environmentally benign these resins are; it's hard to imagine they're as green as polylactic acid.

Brilliant RepRap video (thanks to Emeka Okafor)

I am deeply indebted to Emeka Okafor, author of the Timbuktu Chronicles blog and director for the TEDGlobal 2007 conference in Tanzania, for stumbling across this brilliant Poptech video of Professor Adrian Bowyer, the inventor of the RepRap fabber. I would also like to thank Mr. Okafor for giving attribution to my nanotechnology blog, and call attention to his postings on technologies that can help Africa and other developing regions. There is an Emeka Okafor who plays basketball, I'm not sure if it's the same guy.



Bowyer talks about the economics behind the project, particularly its ability to empower communities that are now economically depressed. There is some yummy game-theory stuff in the paper linked here that does not get mentioned in the video, check it out. He also talks about using polylactic acid (wikipedia) as a printing material for the RepRap. This is significant because you can make PLA from starchy vegetables like potatoes and corn, and when you're finished using your PLA object, you can compost it to help grow next year's crop of starchy vegetables. You can have a closed-loop local manufacturing economy that doesn't require trucks or trains or ships to move products around. In fact there are several materials under consideration, and thought has been given to printing a single product from multiple materials. The Fab@Home folks also have an impressive list of materials that can be fabbed, including chocolate.

I got curious about PLA and did a little googling. In a RepRap forum there is a discussion of just how easy it is to turn starchy vegetables into PLA. From the sound of it, it is non-trivial and demands that the person attempting it be quite knowledgeable. One person compares "home PLA production today to home biodesiel production 20 years ago, when it was arcane, a little dangerous, and rare, but theoretically possible" and notes that for many people it will simply not be economical compared to mail-ordering some PLA. I found a place that sells utensils, plates, and cups made from PLA. NatureWorks appears to be a source for PLA in ready-to-work form.

Starting a fabber blog

Lately I've been thinking and posting a bit about fabbers (also called 3D printers), primarily on my nanotechnology blog. I think the topic (and my growing interest in it) is rich enough to deserve its own blog. I am particularly interested in affordable hobbyist fabber projects, something I might be able to fool around with myself.

The fabber idea is pretty simple. Take a hot glue gun and three stepper motors. Use the stepper motors under computer control (with appropriate mechanics) to position the hot glue gun at a specific XYZ point, and deposit a drop of hot glue. The glue cools and you move to the next XYZ point. Use this arrangement to draw a glue pattern on a horizontal surface, then move up a little bit and draw the next layer, and then the next. Soon you've got a 3D object of almost any shape you wish. A few of the details can vary -- it's not really glue, it's typically a polymer like polylactic acid -- but that's the basic idea.

There are professional and industrial fabbers with prices starting at about $50,000. But more interestingly, there are hobbyist projects to build much more affordable fabbers. The two currently prominent hobbyist efforts are the RepRap project (wikipedia entry) started by Adrian Bowyer at the University of Bath in the UK and the Fab@Home project started by Hod Lipson at Cornell. There are others but these two have the highest visibility and, as far as I can tell, the largest numbers of participants.

The Fab@Home fabber looks more polished than the RepRap, but I find the RepRap more interesting. Partly because it's more affordable (a getting-starting price somewhere around $400 versus $2300) but also because Bowyer is more committed to an open-source approach and is more interested in the implications of that approach. He very intentionally designed a machine that could fabricate most of its own parts and could therefore mostly copy itself. If the machine becomes popular, its price will quickly drop (building one today might cost a good deal more than $400 and a very large investment of tinkering time) to roughly the price of the few non-copyable parts and the raw plastic for the rest.