Sunday, March 16, 2025

building the logo turtle

Seymour Papert started lots of things!

How to build a programmable floor turtle” is on Josh Burker’s (JoshB) site: LogoTurtle

INSPIRATION

Going back roughly 50 years, the inspiration originally came from Seymour Papert’s Logo floor turtle which accompanied the Logo programming language, developed for children.

I was further inspired on reading Neil Gershenfeld’s account in his book, Designing Reality, of a conversation he had with Seymour, back then:

“As fab labs started doubling and the Fab Academy began to grow, Seymour came by to see me to talk about them. I had considered the whole fab-lab thing to be an historical accident, but he made a gesture of poking his side. He said that it had been a thorn in his side that kids could program the motion of the turtle but could not make the turtle itself. This had been his goal all along”
Designing Reality, p. 29

Another goal I have is learning more electronics in a practical way. So, I was on the look out for a meaningful project to help me achieve that.

These factors pushed me over the edge. I decided to build the Logo Turtle!

Following the links in JoshB’s article I bought the materials from adafruit, Core Electronics and some other online and local stores.

There were some mishaps along the way. eg. it’s much better if you can get the 2xAA battery holders with a hole in the middle for the flat head screws. After some searching I found an Adelaide store, Altronics, which had these.

I wrote to Josh and his advice was that I should make a Printed Circuit Board (PCB) since the breadboard approach produced unreliable results. He sent me the Gerber files that I needed for that.

I downloaded a free open source viewer, Gerbv to view the files.

I asked for advice on the Adelaide Maker Space forum about how to get the PCB made and some helpful people suggested a couple of companies. I went with PCBWay and they made the PCB for me.

I have my own 3D printer so I printed the parts in PETG. All the links for that are in the JoshB article.

HELP

I’m an electronics novice so I had trouble finding some of the equivalents between the breadboard design and the PCB design. Fortunately I found Tony Onofrio, a friend in the Adelaide Hackerspace group. He translated the fritzing diagram on JoshB’s article into a PCB diagram for me.

Unfortunately, the link to the LogoTurtle software on JoshB’s article is broken. But I wrote to Josh and he sent me the files. Following his instructions (downloading drivers and Java) I tested the LogoTurtle software on the metro mini board and this was successful.

The software is a Logo implementation in Java. The logo files are text files which you download to the metro board. I didn't understand how it was working but spoke to David, a Java programmer at the Hackerspace group and he explained some of it to me.

The next step was soldering the parts onto the PCB board. This was hard for me since I’m a novice at soldering. Again Tony helped out by giving me some lessons in soldering. The order in which I soldered the parts on was: (1) resistors x 2 (2) Darlington driver, note the notch (3) Metro Mini (4) header pins 2 x 5 then x 3 (5) photocell (6) switch

Having done all this I was ready to attach the PCB to the turtle. I soldered the 4 battery leads, plugged in the stepper motor 5 pin connectors and inserted the 4xAA batteries.

I found some pens with the correct diameter at Office Works and placed one in the pen holder on a sheet of paper. I flicked the switch to turn on the metro power, indicated by a green light and pressed the reset button

Hallelujah, the turtle drew a square! Logo.jar runs the test.txt file by default.

to startup
square
end

to square
pd
wait 1000
repeat 4 [fd 100 rt 90]
pu
alloff
end

But note the angles are not quite 90 degrees. Using trial and error, I changed the angle to 85 degrees and it drew a pretty good square

JoshB’s solution here is to add a shim to alter the angle of the stepper motors reproduce. I tried this but it didn’t make any difference.

I wrote to JoshB again and he suggested I alter the sys.txt file where the logo drawing procedures are stored as text files.

So I altered the rt and lt turn procedures by multiply and angle by 85/90. This then drew a perfect square.

to rt :n
make "n :n * 235 / 100 # (the multiplying factor was altered from * 25 / 10)
repeat :n [rstep- lstep+]
alloff
end

I then tried a pentagon, square and triangle combined:

The more ambitious rotating octagon worked well first up:

Then I made a similar change to the arcrt (arc right) and arclt (arc left) procedures and then I could draw near perfect circles and arcs.

An interesting feature of the design is the photo resistor. When exposed to the light the resistance goes down. This photocell is plugged into A0 on the Metro Mini, so you can introduce this value into the code to achieve variations based on light intensity.

Following JoshB's notes I established the A0 values for a bright flashlight were roughly 960, for normal light 830 and with curtains drawn about 565. So I ran the following procedure in normal mode and flashlight mode which modified the size of a circle:

to startup
wait 1000
let [n a0 / 10]
repeat 10 [
arcrt 50 :n
make "n a0 / 10
]
alloff
end

So far, so good. I could draw closed shapes with the LogoTurtle.

But to draw people's initials, for example, you need to be able to lift the pen (logo command pu) and put it down again (pd) at the right times. This requires fitting a servo to lift the pen. I also added a weight to the pen to ensure it drew firmly on the paper when down.

Here are a couple of initials I drew, using the alphabet file from JoshB's LogoTurtle Curriculum. I presented these to a couple of members of the Hackerspace group who have been helping me:

REFERENCE

Josh Burker's original article: LogoTurtle
LogoTurtle Curriculum (lots of great ideas here)

Saturday, March 08, 2025

dragon and egg 3D print

I printed this one on my Prusa MK4 with multi-colour PLA filament:
inside the egg
outside the egg
on top of the egg

Source files:
threaded dragon egg
Small baby dragon (printed half size)

Friday, February 28, 2025

new laser cuts and engraves

Some new cuts / engraves done by me at the Adelaide Maker Space:
Source of files: 3axis.co
Penrose tile, good explanation here
Penrose chicken, brief elaboration here
Soldering iron bit holder. I will give this to the Hackerspace group to say thank you for their help.
USA jigsaw puzzle. Looking for ways to reduce the burning around the state names and making the small state words more readable.
Cats - laser cut by wolfpaw98 on Thingiverse: https://www.thingiverse.com/thing:2259603. Quite difficult to assembly these. Need a small file to trim the joins.

Wednesday, January 22, 2025

microbit neopixel hat

Hat plus duct tape minus electronics

I've built something similar before (link) using a Circuit Playground Express or CPX. The original idea came from Rob Morrill who has developed a series of excellent project for the CPX, here. Follow the instructions there to fill in the gaps of this account. Alternatively, design your own hat.

I left my neopixel hat behind in Alice so it's time to do it again, but this time using the more popular microbit.

Materials: Cardboard, cardboard cutters, duct tape, clear sticky tape, adafruit neopixel strip 0.5m, battery pack 2*AAA or 3*AA (better, I've ordered some), velcro.

The neopixel strips are advertised at adafruit to work with 3-5 volts DC. However, they can underperform without sufficient voltage as the batteries go flat. The microbit pushes out a max of 3.3 volts, so it's desirable to used a 3*AA battery pack for 4.5 volts which is then regulated down to 3.3 volts by the microbit.

I had to visit a couple of Bunnings stores to get cardboard of a suitable length, since my big head has a circumference of 58 cm. I like duct tape to stick things since they remain stuck. But use clear sticky tape to attach the neopixel strip.

What code to use? I plan to use this hat as a demo for the Adelaide Maker Space / Hacker Space groups so I opted for rainbow colours at the front which activate with sound combined with flashing white / black neopixels at the back and a sound bar graph on the microbit itself. Here's the breakdown:

Initialise the neopixel strip

Flash black and white with 16 pixels around the back of the hat

Rainbow effect on both sides at the front, needs sound to activate

Bar graph on the microbit, responding to sound

Finally, the video:

Monday, January 13, 2025

books and articles I am reading in 2025

The list will include some significant online articles too:

Banks, Iain M. Consider Phlebas (1987)
Blum, Hila. How to Love your Daughter (2023)
Capek, Karel. War with the Newts (2001)
Deutsch, David. The Beginning of Infinity: Explanations that Transform the World (2011)
Dalmaris, Peter. Maker Education Revolution: Learning in a high-tech society(2017)
Gershenfeld, Neil; Gershenfeld, Alan; Joel Cutcher-Gershenfeld. Designing Reality: How to Survive and Thrive in the Third Digital Revolution (2017)
Gibson, William and Sterling, Bruce. The Difference Engine (2014)
Harari, Yuval Noah. Sapiens: A Brief History of Humankind (2011)
Hatch, Mark. The Maker Movement Manifesto: Rules for Innovation in the new world of Crafters, Hackers and Tinkerers (2013)
Noble, David. Forces of Production: A Social History of Industrial Automation (2011)
Pickering, Andrew. The Mangle of Practice: Time, Agency and Science (1995)
Sunfounder ESP32 Learning Kit
Tech Explorations
TechSpace Learning
Weir, Andy. Project Hail Mary (2022)


Previous: books and articles 2024

Monday, December 30, 2024

Fab as a new literacy

Literacy: From Writing to Fabbing (2012) by James Gee (extract, read the full essay here)

best quote, although there are many great ones: the word becomes flesh; the flesh becomes word

IMO a very elegant argument about how Fab is becoming a new, two way street, literacy. Design literacy for digital fabrication is every bit as fundamental as reading and writing. Yes, we have some way to go but we are on that path.

The Maker Movement opens up yet another set of design kits, another set of literacies, what we can call “maker literacies”. Maker literacies are not new. People have been making things like quilts and furniture at home of hundreds of years. What is new is the proliferation of making and the ways in which everyday people can compete with businesses, experts, and industry today thanks to digital media. The special part of the Maker Movement I want to concentrate on here is digital fabrication, what we can just call “Fab”. Fab is the newest literacy beyond digital literacies.

Fab is also a code that allows humans to produce and consume meanings interactively and to engage in joint activities. The code is a mapping from ideas (concepts) to real things via computational computer code.

Oral language refers to things in the world. Language is indexical in the sense that it points to or refers to things, but it cannot touch and handle them. Things always stay just out of reach. Digital literacies simulate things, virtual things that can be handled and transformed by the very code that produces them. But like language, digital media cannot touch and handle real things; it can just manipulate them on a screen.

Fab makes real things. It can handle and transform them. It has been argued that what constituted human intelligence in the beginning was our ability to think and plan in our heads deeply prior to acting . Digital media greatly enhanced this human trait. Such media allow us to think and plan on screens in forms that go far beyond the powers of unaided human thought.

Humans have always, of course, been able to make things. Indeed, some scholars have defined humans as tool makers and homo faber. But prior to Fab making was a one-way street. You could go from conception to construction, but not back again. Fab makes making a two-way street. We can now turn bits (digital code) into atoms (things) by “printing” the code and we can turn atoms into bits by reality capturing devices that digitize things and make them into digital code. “Printing” here means machines that can add or subtract material to make things on demand from digital code.

Language and digital media are complementary. Language is good at creating abstractions out of lived experience by finding and naming patterns in that experience. Writing takes abstraction to its furthest extent, especially in special symbol systems like mathematics. Digital media is good at creating new experiences or mimicking old ones. Digital media allow us to think through external images and simulations and not just through conceptual abstractions. One of the greatest powers of digital media is that it can allow people to have experiences that are hard for humans to have in the real world (or to have more than once), experiences that, nonetheless, words can refer to, such as being an electron or sky diving without a parachute. Digital media can, thus, greatly enhance the ability humans have to find and name patterns in experience, the basis of language and learning.

Think of Dungeons and Dragons played as a role playing game with paper and pencil. This is traditional literacy. Here players use words and other symbols (and the occasional plastic figures) to create images in their heads (imaginations) and in the other player’s heads. A video game (including a D&D game like Neverwinter Nights) involves players manipulating images on a screen, not in their heads. Imagination becomes externalized. One is not better than the other. They are complementary ways of thinking, learning, and problem solving.

Fab, our newest literacy, involves a code that maps from ideas to atoms (and back again) via bits. What you can design in a computer, you can order machines (“printers” and “extractors”) to make. What is in the world can be captured digitally (“reality capture”), put in a computer, re-designed, and “printed” back out into the world. The atoms can be materials, cells, or chemicals. Humans are on the verge of erasing the lines between the imaginary, the digital, and the “real” and moving effortlessly back and forth among them. Bits no longer need to create just virtual things; they can now create real ones. In turn, real thing can now easily become virtual ones.

The day may come where we can “print” an organ like a liver or even (the initial cellular plan for) a living thing like a dog. As of now we can print skin, cells, cakes, and houses. Fab is not indexical. It doesn’t point to things. It is not a simulation. It does not make just virtual things. Fab is material. It makes and manipulates matter. Fab trades not in concepts or simulations alone but in physical things as well. It is the “word become flesh”, formerly the domain of magic and religion. The ideas in our minds and the images on our screens can now be born in the world and the world can enter our minds and computers to be re-born as something new. A whole new material form of thought and planning opens up for humans.

Fab is a set of design kits to make things into bits and bits into things. It creates an entirely new way of writing and reading the world. Fab will proliferate into different literacies, different ways of producing and consuming meaning for different functions, accompanied by new registers of oral language. Fab is a cultural invention like literacy. It will without doubt create social gaps and inequalities if we let it.

Fab is a form of literacy where production (“writing”) is the main form. It finally reverses the polarity of traditional literacy and digital literacy, where consuming (“reading”) proliferates, but production (“writing”) does not, creating priests and laity. To be literate in Fab you must be a maker or at least know how a digital object will translate into a real one (and vice versa). It is as if we had demanded that to be literate in writing you had to be a writer and not just a reader, to be literate in digital game literacy, you had to be a designer and not just a player. In fact, a culture of Fab could lead to just such demands.

Just as writing made new demands on and demanded new skills in oral language, and digital lieracy made new demands on and demanded new skills in both oral language and written language, Fab makes new demands on and demands new skills in oral language, in literacy, and digital literacy. The ecology of oral language, of writing, and of digital literacy—and their various combinations and integrations—will change. Language, literacy, and digital literacy will become yet more complicated. The social gaps in each will compound, along with whatever gaps Fab literacy creates unless we will it otherwise.

Fab could create a world with yet deeper inequalities than we currently have, a world where only a few engage in the alchemy of turning ideas into bits into atoms and back again. The rest will live in a world where the stuff of life and the world--objects, cells, materials—are owned and operated by only a few. Fab is a new literacy and we have as yet no real idea how it will work out. But it is a special and, in some sense, final one. For centuries, since Shakespeare at least, being modern has meant to fashion oneself and writing has played a massive role in this process. Now being modern will mean to fashion ones world as the stage on which one plays and lives

Each new literacy ups the ante on ethical questions beyond issues of inequality. Words can hurt and harm, we know. Writing can greatly spread that harm. Digital media can spread it yet faster and further. But Fab can literally remake the world we live in, exhausting it or expanding it, destroying it or renewing it. Fab can make and remake the very stage on which we humans act for good and ill.

How many of us will get to be homo faber? Humans have always been the ultimate took makers. Soon the tools for world making will be cheap enough to be in the hands of everyone, should we want to make that happen. Will we, as a species, make a better world or a worse one when some or many or all of us become god-like creators, calling worlds into being?

Tuesday, December 24, 2024

ant and eagle laser cuts

Someone at the Adelaide Maker Space mentioned 3axis as a good site for free vectors for laser cutting.

Yes, it is! I downloaded an ant and eagle design from there, laser cut them, built and glued the models.

They are called puzzles and you do have to do some tinkering to get all the pieces in their correct places. Fortunately, my friend Pat was there to help out when I got stuck.

Here are the designs in lightburn and pics of the final products:

Friday, December 20, 2024

Fab Labs haven't been growing exponentially

The Gershenfelds make the claim that Fab Labs are growing exponentially every 18 months in their 2017 book, Designing Reality (p 11 and pp 100-102) and follow up articles (Digital Fabrication and the Future of Work, 2018)

They actually claim that this new growth is a continuation of Moore’s Law and this fuels their “third digital revolution” rhetoric (book, p.102)

I wish this was true but it’s not.

This rose coloured glasses rhetoric has puzzled me. There remain significant barriers to setting up and maintaining a Fab Lab. The Gershenfelds point out themselves that training Fab Academy alumni to the daunting skill level required follows linear growth.

Here are the figures from their 2018 article:

In this article they speculate that there will be 25,000 Fab Labs by 2026

The Gershenfelds then predict that Fab Lab growth will level off because by 2026 the machines will be so cheap and improved that personal fabrication will replace Fab Labs

The 25,000 Fab Labs prediction corresponds very roughly to 4 doublings over the 10 year period, 2016-2026, ie a doubling every 2.5 years, not 18 months:

(1,300 2,600 5,200 10,400 20,800
or 1300 * 2^4 = 20,800

However, if we go to the Fab Foundation home page, the figure cited there for the number of Fab Labs currently in the world (December 2024) is 2300 +

So the doubling time since 2016 has been 8 years, not 18 months or 2.5 years! Also, as I pointed out in my earlier article, fab transformation hurdles, Fab Lab / Maker Space growth in Australia has stalled

There are plenty of reasons identified in the Gershenfelds book about why Fab Labs haven’t continued to grow exponentially. I think their book contains plenty of realism as well as hype.

But they still maintain their highly optimistic exponential growth rhetoric about digital fabrication. The most recent writing I have found by the three brothers is in 2021 on the "Centre for Bits and Atoms" site, where they say:

Digital fabrication today is at approximately the same stage that digital computation was in the early 1980s, when personal computers gave millions of people access to a capability that had previously been limited to large organizations. PCs were to be followed two decades later by billions of mobile devices and trillions of connected things.

Today we have thousands of fab labs, with the potential for making millions of personal fabricators — small-scale fabrication systems for individual use — and a research road map leading to a future with billions of universal assemblers, and then trillions of self-assembling systems in future decades. As with the exponential improvements of the earlier digital technologies, each of these stages of development promises to be faster, better, and cheaper.
- The Promise of Self-Sufficient Production

In all our arguments and discussions we need to avoid the hype cycle rhetoric.

Nevertheless, community Fab Labs and school based Fab Learn Labs are still great things with enormous potential IMHO. I have outlined some of the reasons why in my earlier article fab transformation hurdles

As the authors say in their original book digital fabrication is both hard and rewarding. This quote sums it up:

"Digital fabrication is hard. It introduces a set of new competencies, including the navigation of continually evolving CAD and CAM software as well as additive and subtractive hardware, embedded computing, and an understanding of the biological and chemical properties of the materials used in fabrication. It also requires design thinking, creativity, collaboration, problem solving and resiliency. These all require knowledge, skills and mindsets that cross very different disciplines and domains and, as a result, are not currently well integrated. We define fab literacy as the social and technical competencies necessary for leveraging digital fabrication technologies to accomplish personally and professional meaningful goals, as well as a commitment to the responsible use of the technologies. We cannot build towards a more self sufficient, interconnected, and sustainable society without widespread fab literacy." (p. 64)
Update 26/12/24:

I sent this to Neil Gershenfeld and he was good enough to respond, as follows:

But at FAB24:

https://fab24.fabevent.org/

I spoke about two reasons why counting labs was no longer relevant:

  • With the proliferation of mini-labs, superlabs, biolabs, fab hubs, ..., a single number no longer applies
  • What matters at this stage is counting the impacts of the programs that have matured -- student outcomes, fab city metrics, businesses incubated, ...

Tuesday, December 17, 2024

fab transformation hurdles

Background reading: Designing Reality: How to Survive and Thrive in the Third Digital Revolution by Neil Gershenfeld, Alan Gershenfeld and Joel Cutcher-Gershenfeld.

Some write their stories in words. Some write their stories in code; some with materials; some with machines. My current story is a wobbly exploration through all these media to understand the Fab Lab.

Neil Gershenfeld has articulated his Fab Lab vision now for 2 decades: “How to make (almost) anything”. After a brief revisit of what a Fab Lab is this article outlines some of the hurdles that have to be overcome to achieve that vision.

The Gershenfeld interview with Lex Fridman was fascinating IMO

Digital computation has led to the smart phone. Digital communication has led to the Internet. These first two digital revolutions have created new jobs and transformed traditional jobs. Will digital fabrication continue this trend. Is it correct to claim, as the Gershenfelds do, that digital fabrication is the third digital revolution? See Footnote.

What is a fab lab? Digital fabrication is often misunderstood in that people think of it as being just 3D printing. It actually involves a wide range of additive and subtractive technologies, as well as computer-aided design and embedded electronics

The five types of machines found in a conventional fab lab are:

  • Vinyl cutter
  • Laser cutter
  • 3D printer
  • CNC machines
  • Digital Embroidery machines

The MIT course that Neil Gershenfeld initiated in 2003 named “How to make (almost) anything” was a huge hit which led to the creation of Fab Labs around the world. An inspirational slogan!

What sort of things can we make? Well in theory the list goes food, furniture, and crafts to computers, houses, and cars.

What is the overall goal here? The short term killer app is personal fabrication, the ability to make or modify what you can't or can buy in a store. Personal fabrication can take many forms since it depends on each person. My 3D printed personal favourite so far is the Sierpinski Pyramid Lamp.

One possible social goal is to transform consumers into producers. The Gershenfelds approve the Blair Evans vision:

A potential vision for this new blend is represented in the inspiring work of Blair Evans, an accomplished automo­tive engineer and educational leader who is now developing a local ecosystem of fab labs in an economically distressed part of Detroit. His vision is about what he calls “thirds”— building out the digital fabrication capability to the point that people might spend one-third of their time in paid labor to buy what they can’t make, one-third of their time using digital fabrication facilities to make what they can (with a focus on furniture, housing, aquaponic food pro­duction, and other practical things), and one-third of their time to follow their passions in whatever way they choose
- Digital Fabrication and the Future of Work

However, in practice, what you can presently make depends on whether your local Fab Lab has million dollar machines or thousand dollar machines. In practice many fab labs can make very cool small things (eg. an articulated dragon on a 3D printer) but are not making big things. To make the bigger things you would need the big machines, like a CNC milling machine. Yes, the price will drop and access will improve over time. But for now it depends on where you live.

Not every Fab Lab or project ends in success. Neil’s brothers, Alan and Joel Cutcher-Gershenfeld sometimes play the devils advocate in their book. When things don’t turn out the inspirational slogan “How to make (almost) anything” transforms into “How to (almost) make anything”

A case in point. I tried for 3 years to initiate a Fab Lab in Alice Springs. See my 2021 article Your town needs a community Fab Lab

I lobbied government, industry leaders, education leaders and citizens there. But to no avail. My calls were sometimes not returned and in the instances where interest was initially shown it never led anywhere significant.

I did have more success in introducing new innovative subjects and 3D printer technology at the school where I taught. The admin could see the need for a more engaging STEM or STEAM curriculum. But at no stage was I offered the opportunity to explain Neil Gershenfeld’s full Bits to Atoms vision. It felt like being at a banquet but only allowed to eat the grapes.

My failure to kick start a community Fab Lab in Alice Springs could be put down to my poor persuasive powers. However, it might also have been due to deficiencies of the local ecosystem, a troubled town of 25,000 people, to nurture innovation. Neil Gershenfeld points out that MIT isn’t an isolated technology park but is embedded in an ecosystem or environment “that mixes long-term research, short-term development, small start-ups and large corporation, along with cafes, clubs and parks” (p.49)

Furthermore, I notice that Fab Labs are not growing exponentially in Australia, unlike some other countries. On the contrary, if you look at the map some Australian Fab Labs have become inactive (Perth, Ballarat, Sydney). As the two sometimes critical brothers point out, “Digital Fabrication is hard” (p.64)

So, in this article, I want to discuss the hurdles as well as the tremendous potential of setting up a Fab Lab. In 2024, I moved back to Adelaide so will reference the Maker Spaces here.

A Fab Lab needs machines, software, spaces and people who understand (mentors, volunteers)

Space is a huge issue. There are two maker spaces in Adelaide. The Adelaide Maker Space has a huge space in the basement of the WEA Building. The Parks Library Maker Space is part of the library system and has only a smallish room, which does restrict things.

Machines: I listed the 5 types of machines above. An important issue here is enough commonality to allow for interoperability between different Labs around the world. From my reading the most popular machine is the laser cutter. The problem with 3D printers is that they are slow. I noted with interest that Neil Gershenfeld’s favourite machine is the CNC miller. The Fab Foundation site has a page where they specify how to get started and their ideal Fab Lab. For those interested in starting or understanding a Fab Lab there are lots of important details on that page.

Software: Free and Open Source Softwar (FOSS, eg. Inkscape for 2D vector graphics design) lowers the barrier to interoperability but this is not always possible. I’ve noticed some comments in the book (eg. from Nadya Peek, p. 73) about the need to improve CAD / CAM software to make it more intuitive for users

Network effects aka Metcalfes law: the value of a computer connected to the Internet is proportional to the square of the number of computers in the network.

When the digital fabrication hardware and software is interoperable across locations, it enables network effects, greatly accelerating the innovation in a way that is not possible with analog fabrication. I'm wondering if the Maker Spaces in Adelaide could exploit this more. For example, one thing that has surprised me is that although it is very easy to find free 3D print designs online (thingiverse etc.) it is not easy to find laser cut designs. If this global sharing of designs which is embedded in the Fab Lab charter is a reality then why are laser cut designs hard to find?

In this sense digital fabrication is revolutionary but only when linked to the earlier digital revolutions of computation and communication. I have a sense that the Australian Fab Labs are operating too much in isolation from each other and the world global movement.

People: The Adelaide maker space in the WEA basement is staffed entirely by volunteers. This surprised me but it seems to be working. There are induction sessions to get started on particular machines, projects or rooms. There isn’t a formal ongoing mentoring system. If people are stuck then they can ask a volunteer for help. This often works but not always. eg. I had a problem where the laser cutter simply stalled at the start which neither I nor the volunteer could solve.

The Parks library is staffed by a couple of paid workers who are expert makers. They have an induction system and you can make appointments if you need to skill up in a particular area.

Community: I spoke above about killer apps and how I made a Sierpinski Pyramid Lamp. Another way to look at this is about "must haves". What "must haves" do Fab Labs offer? The Blair vision of making one third of your consumables in a Fab Lab may be achievable in the futue but not in the present. The Gershenfelds argue a strong point here: that one of the "must haves" is the sense of community attained through the meeting and making process (p. 77 and 81)

Fab literacy and the Fab Academy: Given that expert people are the main limiting factor for Fab Lab expansion the Fab Academy runs a 24 week course to train people. I’ve had a look at this course and find it quite daunting. There are only two places in Australia where you can complete this course:

Course details (look here to understand why I find it daunting):

Neil Gershenfeld calls this a distributed learning model (a hybrid between F2F and online learning, since part of the learning is done socially at a FabLab). Online MOOCs are notorious for their high drop out rates so it’s an improvement on that model.

Money: Sherry Lassiter from the Fab Foundation estimates that the average budget for launching a community fab lab and running it for 2 years is $250,000. (p. 76)

The Adelaide maker space has various sponsors, scroll down to the bottom of their home page. They have membership fees and fees for visits, inductions and workshops for those who aren’t members.

Neil Gershenfeld has some interesting discussion about who pays on page 42 of the book. He says that selling things made in the lab doesn't work partly because Fab Labs are not setup to make things at scale. He goes on to point out that enlightened government can utilise Fab Labs to help disadvantaged youth stay out of trouble, that is a better option than what happened in Alice Springs (lock 'em up and get more police).

Philosophy: The how, what and why all need to be addressed. "How to make (almost) anything" implies that users have open slather on the what. But in practice that depends on their expertise. Learning works best when the users make something that is personally or socially meaningful, the why. The how is mastery of all the hardware and software which is a big task. But to focus only on that would be a mistake.

Conclusions:
  1. How to make many interesting things is not as inspirational as How to make (almost) anything but is more realistic at this stage
  2. Third digital revolution and turning consumers into producers are probably over hyping the case
  3. Fab Labs / Maker Spaces can have many great outcomes: rapid prototyping, training ground in useful skills for all and joyful community development for starters
  4. The future is bright since the technology will continue to improve, become more user friendly and cheaper
  5. Australian Fab Labs / Maker Spaces need to tap more into the global movement by sharing their designs (open source philosophy)
FOOTNOTES:

I tend to agree with this amazon reviewer that all the Gershenfelds are wearing rose coloured glasses with their "third digital revolution" rhetoric. Note, however, that in a 2018 article they said that exponential growth of Fab Labs would die out by 2025:

If you want to be proselytized about fab labs, this is the book for you. A key premise is that an analogy of Moore's law will (or should?) apply to digital fabrication. This is based on a few years of doubling of the number of fab labs out there. Moore's original paper was based on 10 years of data but the trend there has continued for 50 years. If that holds for fabbing, yeah, it'll change the world bigtime. But the case has yet to be made. I liked that the Gershenfeld brothers wrote different chapters of the book, with quite different life experiences they bring different perspectives. But it's all based on that exponential premise, one that I'm quite skeptical about. The last of Neil's chapters envisions how fabbing might eventually get to assembling very tiny parts so you could really make anything, but this is almost laughably sketchy and technically infeasible. There's something called chemistry that Neil doesn't seem to be paying attention to. Still, fabbing is a fascinating new technology with lots of possibilities and this book will give you a good feel for how it's affecting some people's lives. There are some good stories mixed in with the questionable extrapolation of trends.

Saturday, December 07, 2024

making a 3D mesh with tinkercad

We are going to make this starter mesh, the triangle interweaves with the hexagon and all parts can be moved around. Once you know how to make this starter it will be possible to extend the mesh further.

My over arching reference here is a wonderful article by Jose Antonio, How to Design and 3D Print Flexible Meshes, who explains in detail the conditions under which 3D printers can bridge, ie. print over thin air!

You can use Tinkercad Codeblocks and Tinkercad 3D designs to create flexible meshes

Open Tinkercad https://www.tinkercad.com/ and load Codeblocks

We are going to make this hexagon prism with cut away holes:

Here is the annotated code for the hexagonal base and frame. I've stolen Jose's code and added some annotations to explain it.

Export the object as a Shape: Export > Shape.

Then open Tinkercad 3D designs

Your Codeblocks creation can be loaded from the Shapes library > Your Creations

“You won't be able to take it apart like a grouped 3d design, but you can drag and use it as a design component in any 3D design”

I named my new tinkercad file hex_prep

Next, we will make a triangle to fit into the holes in the hexagon. I worked out the dimensions of the triangle from one of the links in Jose's article:

Using these dimensions I made this code to make the triangle:

I rounded those measurements in Codeblocks

To find the scale factor for the inner triangular hole:

Scale = (22 – 2.2 )/ 22 = 19.8 / 22 = 0.9

After applying this I then found I had to move the triangular hole 0.9mm up the Y axis to obtain equal thickness sides of the triangle. This was arbitrary guess work, if you can explain where I miscalculated let me know please! The problem is that the triangular hole does not centre.

Name it tri or triangle and export as an STL

Then import into your tinkercad hex_prep file

We are aiming to make this:

Make two duplicates of the hexagon Ctrl + D then rotate them so they are lined up. To fine tune rotation use the outer ring and hold down the mouse button

You now have to position the 3 hexagons and triangle correctly

Some Tips:

  • When necessary hold down the mouse and use outer ring for rotation (more fine control)
  • At the right time set Snap Grid to 0.1 mm
  • Ctrl + up arrow to raise the triangle. Raise the triangle by 0.1 mm at a time until you see a clear airgap, both below and above the triangle.

Important: There has to be a visible airgap above and below the triangle!

Print this one as a trial before moving on

  • Select and group
  • Export as STL
  • Load into your slicer and make the GCODE

Then a miracle occurs! The triangle is printing on thin air!

Here's a mesh that has been extended further

Wednesday, December 04, 2024

my job application cover letter

MY PREFERRED LEARNING APPROACH: 21stC MAKER EDUCATION

Where I claim to have a deeply thought out, innovative approach to learning and teaching:

The three game changers of 21st learning are block coding, micro-controllers and the Fabrication Lab. These can be integrated in various ways. Bits to Atoms; Atoms to Bits. I agree with Neil Gershenfeld that this is the path to the third digital revolution. Understanding this is a very big deal in my opinion.

My background qualifications are in Science (specialisation in Chemistry). But when computers came along I became an early adopter, particularly of the educational computing language logo (which has since evolved into Scratch). I was persuaded by Seymour Papert’s book “Mindstorms” that logo offered a more engaging way to teach maths, as well as computer science. Fast forward to today and Scratch coding has become a multi media story telling fun machine accessible to nearly all students. Sadly, this still isn’t appreciated by many teachers and school leaders. Block coding (be it Scratch, Makecode or SNAP!) is accessible and enjoyable for 95% plus of students. I call this “the wider walls”.

Seymour Papert was also an educational theorist. He spent some time collaborating with Piaget and developed the constructionist theory, a portmanteau of Piaget’s ‘constructivism’ (learners develop their own meanings) and ‘construction’ (we learn by building meaningful things). I am one of those rare teachers who studies educational theories and selected PhD theses. The constructionist approach continues to grow today led by Neil Gershenfeld (community Fab Lab), Paulo Blikstein (schools Fab Learn Lab) and others (Gary Stager, Sylvia Martinez, Yasmin Kafai, Josh Burker, Mitch Resnick, Brian Silverman etc.). This approach informs us how to design learning environments which promote highly engaging, self directed powerful learning.

However, I am not a one eyed constructionist. After years of searching I was surprised to find Diana Laurillard's integration of a range of different learning theories. Her approach is The Conversational Framework which combines Instructionism, Constructionism, Social-cultural learning and Collaborative learning into a meaningful whole. As well as learning by meaningful building, the social learning and collaboration has to be built into the programme (as well as essential Instruction).

In 2021 I was invited by Gary Stager to contribute to a book, 20 Things to Do with a Computer: Forward 50 commemorating the 50th anniversary of the seminal paper by Cynthia Solomon and Seymour Papert, “Twenty Things to Do with a Computer.” My contributing article was titled The Wider Walls, which developed the theme of making computational thinking available to all.

A good theory informs and improves practice. However, as well as the right software we also need the right hardware. Furthermore, creative imagination is another essential ingredient.

In my previous school I helped develop a subject called Artbotics (Craftbotics would have been a better name) where year 7 students made their own creations, mainly with cardboard, and controlled them in various ways (motion, lights, sound) with the Circuit Playground Express micro-controller, an appropriate alternative to the microbit.

The micro:bit is the ideal micro-controller. It is far more accessible than the Arduino because it runs on block code (MakeCode) and has controllers on the board.

STEM is a reasonable acronym but it’s better to extend it to STEAM with the amazing Turtle Art software and other ideas. For example, I accomplished this in a subject named Inventiveness. This took the form of the “Turtle Art Tile Project”. Students used Turtle Art to design attractive geometric shapes, then 3D printed them, then impressed them into clay and finally painted and glazed them. This was an impressive and engaging exemplar of digital fabrication or the bits to atoms approach.

Perhaps my most successful recent work was when my school experimented with the curriculum to setup my Year 8 class with extended learning times (2, 3 or 4 hour lessons became the norm). I created a subject called Fabulous Fabrication where students worked in groups to develop their own designs assisted with the microbit and 3D printing technology. The proof of the pudding here was that students repeatedly asked me if they could keep working through their recess and lunch breaks.

I am always on the lookout for new approaches which combine learning with modern technology. As well as the software and hardware mentioned above I have also experimented with Game Maker, 3D printer construction from kits, laser cutters, Hummingbird bit, ELECFREAKS kits, Spike LEGO, Makey Makey, TapeBlock (electric circuits for the disabled), drones, Raspberry Pi, Wolfram Alpha, CAD software (Tinkercad including CodeBlocks, Inkscape, Lightburn), microBlocks and a range of IDEs (VS Code, Jupyter) and Python libraries (Pygame, Matplotlib, Pandas, Django, Pytorch ...).

I have documented these and other learning experiences on my blog (https://billkerr2.blogspot.com/) Here is one sample article which outlines my preferred approach in more detail: Bits-and-Atoms-part-one

That is possibly enough to flesh out my dot pointed CV, the aim here was to provide more of a big picture overview of my educational philosophy, theory and practice.

Wednesday, November 06, 2024

engraving a photo with a laser cutter

Starting with:

First up, this requires some awareness of the difference between raster and vector images

Raster files are composed of pixels., eg. a normal photograph. In this case the format was JPG. Vector files use mathematical equations to make geometric chapes, lines, and curves with fixed points on a grid to produce an image. A common vector format is SVG.

Raster images are challenging and require more preparation before engraving or etching them with a laser cutter. You need to start with a photo with lots of contrast, eg. with a pure white background and pale clothes to contrast darkish hair (or trim the photo as I did).

One technique is error diffusion raster (Stucki, Jarvis, FloydSteinberg). The darker the grayscale value, the denser the points are set. The point size remains unchanged.

I'm a GIMP user (open source), not a Photoshop user. For my needs I found a couple of good tutorials online:

GIMP tutorial
  • Scale image to 300 px/inch
  • Convert to black and white
  • Histogram adjusted for good range of dark and light areas
  • Adjust colour levels histogram towards the centre
  • Adjust colour curves to boost the contrast
  • Apply sharpening

After the GIMP tutorial I then applied this YouTube Lightburn tutorial:

  • import and select the image
  • tools > adjust image Alt + I
  • Best image mode > Jarvis or Stucki
  • DPI – approx 300
  • To sharpen:
    • Enhance radius: 25
    • Enhance amount: 100
  • Lighten the face and remove background dots:
    • Brightness: 7

Note that the Preview normally looks poor and can be safely ignored! But you can get the time estimate through Preview.

After treatment with the two tutorials:
Laser cut version onto MDF (Medium Density Fibreboard). The contrast is OK but could be improved around the eyes and mouth: