Light Engines

“make objects that use simple electronics to emit gentle light. You may think of them as nightlights.”

Introduction — 11.10

Today we were shown the basics of how to assemble an electric circuit. We would be making ones composed of either one or two LED lights, a mercury switch, a battery pack, and of course the wires that connect them all together. I had never done anything like this before, nor had I heard of a mercury switch. However, I was excited by the potential interactions it affords — when you orient it upwards, the circuit is complete and the light turns on, whereas if you orient it on the side or upside down, the circuit is incomplete and the light turns off.

Notes from lecture

First model— 11.11

I first wired my LEDs to the switch as pictured in the above right drawing. I knew that for my first attempt I wanted to keep things simple while getting comfortable with using motion to manipulate the mercury switch. I chose a simple form — a cylinder — and made the following flashlight-type lighting engine:

First model (passive use)
First model (active use)

In making the model, I made the cylinder with a flat face on which I had two pannels of tissue paper for diffused light to shine through. The space between them was therefore meant to be where you grip the light. Here I gained some preliminary experience in fulfilling one of the significant criterion for evaluating the project: making the form convey to the user how the piece should be used.

When the piece is on the table (the passive use) the light shines up and out when oriented in the on position, and you can roll it until it rests on the flat face, at which point it is turned off. When using it like a flashlight (the active use), the light comes on then you hold the cylinder up in front of you and turns of when you hold it in a resting position by your side.

In making this first model I gained experience in manipulating the mercury switch and working with the other materials we had been told we could use (foam core, white paper, and a translucent paper such as tissue or tracing paper). I also learned about the ways that the form can communicate things to the user, and about the different types of interactions that I could choose to focus on as the project progressed.

Second Model — 11.15–11.16

For my second model, I decided to continue down the path I had started on with the first one. This path being the creation of a light engine that has a very active interaction similar to that of a flashlight, and that clearly communicates through its form how it should be interacted with.

In one of our recent Placing lectures, we learned about how designers have previously made products have dealt with communicating interaction. One example of an unorthodox approach to this is as follows:

Handshake door knob

Here the product communicates how one should interact with it by embodying an indication of interaction that we are already familiar with: the handshake. Inspired by this approach of highly-representational design, I decided to imitate this design in my second model:

For the purpose of making a sketch model, I made a cast of my own hand out of a plastic bag and packing tape, and then began covering it in white paper to show what it might look like when made out of only the materials we were initially prompted to use (white paper, white foam core, translucent papers such as tracing paper or tissue paper). The mechanism, pictured below, was inserted into the base (where I cut off the wrist).

Mechanism for second model

Here I solved the problem of being able to access the battery box by making the whole mechanism removable from the form. This meant that the mercury switch had to be connected to the box, and therefore that the box had to be oriented correctly within the hand so that when the hand was on the table the light would be off, and when you engaged in a handshake with it the light would be on. This was somewhat difficult to control, but I eventually was able to master the insertion of the box into the hand. However, I noted that making this insertion one that a user could easily understand and carry out would be an issue that I would need to address if I chose this idea as the one I would refine.

I began to address this problem when making a removable bulb to house the light in. I made the bulb fit the shape of the wrist, so that it would be clear when the two were separate how they should be unified. This was an idea that I thought could be a useful one for future models — ones where maybe the battery and switch could remain stationary, while the bulb could be removed to allow access to them.

Feedback — 11.17

A group of three other students evaluated my second model today. Together, they filled out the following form:

Evaluation form


  • The form is interesting/engaging — you want to interact with it.
  • The interaction is organic — it is comfortable, relatable, understandable.

Here the merits of the highly representational design are evidenced.

  • The craft needs improving

While this is just a sketch model and I was therefore ok with it not having great craft, I acknowledged that the design of the form and its craft are not separate things that I should choose whether or not to unify, but two qualities dependent on each other — the craft influences the form.

  • This idea is very unorthodox (“halloweeny”)

I was aware that this project was somewhat unrealistic from the start. While I had certainly learned a lot about craft and communication of use, I knew that this was likely not the idea I would choose to refine. While it was a good exercise for my thinking about this project, I could not imagine it being a real, pratical product. Furthermore, I did not want my final project to be so directly influenced by someone else’s design.

Third Model — 11.15–11.16

For my third model, I decided to radically change direction. My second model had a highly representational form, so I wanted this next model to have more of an abstract form. On the basis of this intention, I used a construction method I was already familiar with from past work with foam core to make this:

Interlocking foam core sphere

At this point I had to begin deciding the specifics of how I would make this into some kind of interactive lamp-like light engine. I knew that I wanted the light to shine through the pattern created by the interlocking pieces, preferably diffusing from the center outward. I concluded that because of the way I had constructed this piece (in spherical form), I could not put the LED within the form and still have the light shine through the whole grid. Therefore, I decided that for the purposes of this model I would have to have the light shine up through it from below. I decided on a way that I could achieve this outcome would be to simply suspend the sphere from the ceiling by strings attached to the center:

Hanging sphere

However, I ended up deciding to have a base that contians the mechanism which also has a column coming off of it from which the sphere could hang. The column would go through the center of the sphere, and the strings would attach to the top of it. Then, one could interact with the lamp by twisting the top of the column, causing the strings to wind around it. When they let go, the strings would begin to unwind, causing the sphere to spin above the light source beneath it. This interaction is pictured here:

Sphere spinning around column

While I thought that the spinning interaction was engaging, I concluded that the column and strings and large base that would be necessary to support all this was not the right solution to integrating this form with the lighting and motion I wanted this light engine to have. I decided to look again at the interlocking structure to determine how I could have a light source within it.

Timeline for Project/Criteria for Evaluation — 11.22

Before we left for thanksgiving break (11.23–11.27), we were given a timeline for the rest of the project. We also came up with criteria to keep in mind when evaluating our final designs.


Fourth Model: Refinement — 11.27–11.28

I began by sketching out some potential structures that the interlocking form could have, and determined how the pieces of the form would have to look to make it have the structure that I wanted:

Quick sketches

I decided on the arch-shaped form at the top left corner of the page, as I would pursue the design centered at the top of the page. This design has the interlocking form as a dome that covers a bulb coming up from a shallow cylindrical base. I cut the pieces for the dome first, making sure to keep them at the same scale as the sphere’s for continuity (as I thought this scale would be most effective for the rotational interaction I had in mind)

Pieces for interlocking dome

I then assembled them into the dome:

Interlocking dome

I then made a cylindrical base for the dome:

Fourth model

In keeping with my sketches, I made a small, transparent cylindrical bulb that protrudes from the top of the base. The fact that the dome surrounds the bulb from all sides meant that I could finally achieve the effect of light diffusing through the entire grid of the interlocking form. Also, remembering the lesson I had learned from my second model, I made the bulb such that it could be removed while still anchored by the batteries and switch:

Dome removed from base (left) / Top and bulb removed from base (right)

I then needed to think about the interaction that the user would have with the form. I knew from my work with the third model that I wanted this interaction to be rotation of the interlocking form. I decided that I wanted the user to be able to rotate the dome in either direction by gripping it and twisting to the left or right. For this model, I decided to try having a half-rotation cause the light to turn off or on.

I designed a track system in which the mercury switch sticks up near the wall on the inside of the base, and the top of the base (which surrounds the bulb) would have a track on it that would push the switch down and then let it back up again with each half-turn:

Track system

While not without some apparent issues (involving the aesthetic and overall craft of the base), this idea was certianly one that I knew I could refine into a final piece. I decided to analyze the issues I had identified with this model, and refine the design for my last model.

Peer Interactions — 11.29

Today in class many of my peers interacted with my light engine. Drawn to the form of the dome, they gripped it and turned it as I had intended. However, many of them tended to expect the on/off change to happen after a relatively small rotation. Furthermore, the craft of the track system needed improving, as the switch would either fall off the track or get caught on it because I made it out of tape.

Also, our deadline to complete the final model was changed from 12.01 to 12.06.

Final Model — 11.29–11.05

I decided based on what I and others thought was successful about the fourth model that the dome should remain the same. Having learned earlier in the project about the importance of maintaining good craft throughout iterations, I did not need to remake it. I did, though, redesign both the outer aesthetic and inner workings of the base.

Initially, I worked on changing the form of the base to improve how it looks. I thought that the previous base was too heavy, and that the cylindrical shape was not in harmony with the dome shape in terms of how the dome tapers. I decided on a shorter truncated cone for the base, so that the base would not distract from the dome, and so the curving motion of the dome is continued better in the base, unifying the two.

After failing to construct a truncated cone out of foam core intuitively, I found a website where I could generate a template for the side of a truncated cone:

Base template

I then remembered that in my previous model the shape of the bulb had mirrored the shape of the base. I thought that this had been effective, other than the fact that the cylindrical bulb had not fit into the dome very well. I realized that a truncated cone bulb would both unify the piece and fit the inside of the dome more effectively. So, I made another template for the bulb:

Bulb template

Here are the two pictured together, so their proportions relative to each other are clear:

Both truncated cone templates

I then assembled the base. On the inside, I made a cylinder that houses the battery box and forms the inner wall for the track. I then assembled the bulb, and gave it a cylindrical base that fits around the inner cylinder. I then set up the mercury switch between the inner cylinder and outer wall, sandwiching it between two pieces of paper whose width is the same as the distance between these walls. Finally, I added a rim around the top of the base that would help guide the track system.

Final base

I then worked on the top (the dome). I set about constructing a track system that fit within the ring established at the top of the base. I divided the top into four quadrants, and added tracks in two of them (placed in two non-adjacent quadrants). I made the tracks out of foam core, making sure to use good craft.


I then inserted the tracks into the base, completing the piece:

Tracks going into base

The model in its entirety:


Finally, we were instructed to take four final photos of our work for submission. These included shots of the light engine in its off and on states, a detail shot, and a context/interaction shot.

My final photos:

Off (top left), On (top right), Detail (bottom left), Interaction (bottom right)
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