Five shades of a PCB

I experimented with finishing techniques using PCB’s, Othermill CNC and some chemicals. The most promising colors are shown below:

img_20180926_032800_hdr.jpg  From the left they are: ferric chloride solution for 3 minutes, top layer milled off, original, tined, buffed. From here, I decided on a couple of color combinations and started fabricating.

img_20180926_033213_hdr1img_20180926_033610_hdr1 img_20180926_034203_hdr1


While none of them quite capture the aesthetic I’m going for, the last one warrants further exploration.

Bending PCBs

Prototyping Printed Circuit Boards(PCBs) is now cheaper and easier than ever before. We are seeing a huge increase in the number and quality of small batch custom boards, like DefCon badges.

In its simplest form, a two-layer PCB consists of three layers- a copper layer, a substrate like FR4, and another copper layer. The substrate is generally a lightweight, stiff material. High-quality PCBs have strong adhesion between the copper layer and the substrate.



Desktop CNC’s allow milling PCB’s in-house. When milling your own PCB, an engraving bit is used to mill away the copper on the top to leave the insulating substrate, thus making electrical traces. A thick layer of the substrate is left to provide structural support, as shown below.


The substrate is quite stiff and does not allow bending at most temperatures(although, it has been done). But the copper is quite malleable. So if we mill away most of the substrate, a point bend can be made as shown below. The resulting cut in the PCB can be soldered to maintain the 3D shape as well as to keep electrical conductivity.


Note that this technique is very different from using flexible or semi-flexible PCBs. For one it is much easier to prototype and it results in rigid 3D structures.


Prior art:

Punk Monk- Exploring 2.5D Shapes

I started out exploring shapes afforded by bending PCB material. Specifically, I explored making Miura fold which might allow warped 3D shapes from a single piece, and making a semi-dodecahedral lamp.

After spending some time with the material and process I had a better idea of the possibilities, and it became clear that making the entire toy using this technique is unfeasible. So as a next step, I made 2.5D mock-ups of the final design in 2.5D by stacking paper, first hand-cut then designed and laser-cut.

Content and (dis-)contents: Assignment 1

Container: PCBs

Prototyping Printed Circuit Boards is now cheaper and easier than ever before. This is because of automation of the production process in a large-scale bringing down cost of manufacturing. And, the availability of free tools and tutorials to design circuit boards.


The container offers affordances in the form of layers of materials sandwiched together. The layers are silkscreen, solder mask, copper, FR4, copper, solder mask, silkscreen. From the perspective of a designer, the material offers more affordances than can be easily counted, so I shall focus on affordances to the user of a produced PCB. Here are some of the affordances and great examples of their use to create good content:

  • The copper layer affords passage of electricity. All the other layers provide the anti-affordance of blocking the flow of electricity. e.g. PCB motor
  • The copper layer provides the anti-affordance of blocking light from passing through, all the other layers provide the affordance of letting light pass through to varying degrees. e.g. PCB visual Art
  • The FR4 material provides the affordance of structural stiffness and temperature stability. e.g. PCB drone badgePCB enclosures
  • The copper layer affords to stick to solder and soldermask affords the anti-affordance of repelling solder. Together these afford sticking components on the board strongly and precisely. e.g. PCB Braille signs

Response to in-class questions:

What is content? What makes “good content”? What makes “viral content”? How are they the same and how aren’t they?:
Good content satisfies needs, viral contents satisfies wants.

How is it useful or detrimental to think in terms of content/container? Is there another way?:

Container/content model separates the users from the designers i.e. designers make the container, users use the container to make content. Granted there is often overlap in the people acting as designers and users i.e. a person can be both a user and a designer. Nevertheless, there is seldom an overlap in the thought process of acting as a designer/user i.e. a person seldom acts as both at the same time or in the same mindset. So the divide is valuable. At the same time, I feel like better design emerges from a narrow divide between designer and user, and both should inform and influence each other.

Can the same “content” be translated across different containers?:
Yes, definitely! For example, a painting can be made in any medium, a piece of music can be played with many instruments, The same spice/texture palette can emerge from different ingredients. But also, synesthetic nature of humans means that similar emotions can emerge from different sensory inputs.

Can the same “content” be translated across different containers?:
I put container first, more often than not. In fact, I see the world in terms of simple components e.g. I see a toaster as a heater connected to a timer rather than a means of generating toast(the content). My process is to explore the perceived affordances of a container, drill down to the real affordances and think of which affordances are invisible. Then, make them visible! For example, the copper layer of a PCB affords bending, but this is seldom visible because the FR4 layer affords stiffness. I am currently exploring making bent PCBs to surface this previously less visible affordance.

Can the same “content” be translated across different containers?:
Yes, users deserve compensation from the content they create. Even if it is non-monetary compensation in the form of reputation/credits..


Reflections on the reading:

Two forms of bad writing that I hate are (a) jargon-heavy text with runaway sentences (b) writing that makes universal claims without citation or context. The reading Rethinking Affordance- An Introduction seems to combine the two into a perfect mix of misery. After reading the piece three times I still don’t understand what the author wants to convey other than that they think that ‘affordance’ needs to be redefined for the digital age. I have more issues with the text than can be easily listed, so I shall not attempt to list them.

Punk Monk




The character was inspired by an MP Tourism Ad. Punk Monk is a monk wearing headphones and nodding to a beat. A lot of work went into getting the expression on the face right. I experimented with various facial features and settled on the simplest look with just eyes and a smirk.



The first model is a bobblehead with headphones made out of milled PCB. The wooden model and PCB are separate pieces held together by friction fit.

The wooden model was made out of two wooden dolls. The first one had its head turned down on a lathe to leave a holder for the spring on which the head will rest. A long hole was drilled along the length of the body to pass two wires from the base to the head. The wires act as + and – leads to the LED’s on the headphones.


The head was made by separating the head from another doll. It was drilled down to have a hole in which to rest the spring and a wider hole to allow free movement. Two thumbtacks were pushed into the head where the ears would be and thin copper wires were attached to the tacks to act as electrical connections for the headphones.


The PCB headphones were made out of doubled sided FR4 PCB. They were modeled in OnShape, keeping PCB thickness and size of the wooden head in mind. The PCB material itself is not flexible, but the copper layer on the end is. So at a point of bend, the FR4 material is milled away to leave a thin copper layer, this creates a sharp curve, and the appearance on the outside is that of a continuous copper layer with no breaks. A jig was made to place the PCB in the right shape and soldered on the inside to have it retain the shape. The ear cushions were made by gluing another octagon of PCB material.


Electrically, the PCB has two wires running along the inside length. They are for the + and – pins of the LEDs on either earcup. The LEDs are in parallel. The ear cushions act as the electrical contact to the head through the thumbtacks and are electrically connected to the + and – pins on either end. The leads run down the length of the doll and to an Arduino and battery which pulsate the LEDs.


The base is made of MDF with a hole to hold the doll and another, larger hole to hold the arduino and battery.

The entire model was painted with acrylic paints.


Hello Git- Open Source Studio

I have worked as an engineer for a few years now. And since the very beginning git was part of the workflow. I started out by pushing back. I forced people to send me zipped files and did the version control myself. This works for small projects but it’s terrible for maintaining anything larger than a text file.

I reluctantly accepted git and GitHub; slowly. I started out learning git for maintaining personal projects, with low stakes. I maintained my CV in git, maintained a few Arduino codes here and there. No big deal. For the most part, git was just a way back machine rather than and serious version control. No fancy branching or issue tracking, just a backup for old code, in case I need to get back to it. When my laptop was stolen I doubled down on using GitHub for backup. I now have well over 50 repos, most of them horribly maintained spaghetti code with the last commit made a year ago. They’re not meant for collaboration.

I’ve made a few blunders while using git. I’ve published IP protected code publicly without a license. I’ve had ‘detached head’ errors and ‘merge conflicts’ and while fixing them I almost destroyed repos. But I’ve learned a few lessons from all this. Here’s what I’d tell my past self:

  • It takes less time to learn git than to do manual version control
  • Don’t be ashamed to publish your code. No one’s gonna read it anyway.
  • You can’t push and pull too often
  • When in doubt don’t just read a forum post and use the -f flag. Talk to an expert or think about it.
  • There’s no shame in using a GUI to interact with git. GitKraken is beautiful!

I’m still learning and I’m still making mistakes that seem ridiculous with hindsight. But I’m happy that they’re at least public.

Reflections on readings:

I connected to the message of inclusiveness in multiple readings. Whether it be by simply being polite to n00bs or going out of your way to include diverse groups often at cost to the project. I think more transparency and diversity leads to better projects. That said, the old adage ‘A committee should consist of three men, two of whom are absent.’ also springs to mind. We should be aware that inclusivity comes at the cost of overheads and slower decision making. We should not be quick to forget the fruits reaped by grace of the BDFL’s.

Personally, I will be more mindful and sensitive towards feelings of anonymous people on forums. And practice polite discourse or refrain from commenting.