Aijia Yao

What's a Dalek?

In Doctor Who, the Daleks originated on the planet Skaro as mutated remnants of the Kaled people (Dalek is an anagram of "Kaled"), engineered by the scientist Davros during a brutal thousand-year war. Trapped in twisted, fragile biological forms, Davros encased them in armored shells and stripped away every emotion except hate, creating beings whose entire identity revolves around destruction and ideological purity.

From Wikipedia:

The Daleks are a fictional extraterrestrial race of extremely xenophobic mutants principally portrayed in the British science fiction television programme Doctor Who. They were conceived by writer Terry Nation and first appeared in the 1963 Doctor Who serial The Daleks, in casings designed by Raymond Cusick. ... The Daleks are the series' most popular and famous villains, and their returns to television over the decades have often gained media attention. Their battle cry, a staccato "Exterminate!" (⚠️Check your volume setup ⚠️ before clicking this button▶️ to hear), has entered common usage as a popular catchphrase.

Here are two video clips that showcase Daleks as the first time I watched Doctor Who:

In a way, the Daleks are a sci-fi embodiment of “brain rot”: their thinking is so narrowed, obsessive, and repetitive that they literally cannot process ideas outside their rigid worldview. Hence, our idea of building a Doomscrolling Dalek was born.

How to make a Dalek (TMI warning)

Based on the machine building design ideas as shown on the eecs machine page (link), I'm on the team of the subssystems for Drive actuation, Dalek exterior, Dalek chassis and internal structure.

First thing first, the plunger. The plunger is a crucial component of the Dalek's design, allowing it to interact with its environment, and most famously, to suffocate people as in the video below. To create the plunger, I decided to use TPU as the filament to 3D print the plunger head. I originally wanted to directly use stl files online but then the slicer has a glitch since the mesh is not well-defined so that the slicer would fill in the gaps incorrectly. Then I started with a basic shape and then added details to match the Dalek's iconic look. The TPU 3D print result was great and I attached the plunger head to a metal rod that I had from a broken shelf in my kitchen.

Then magically, on Saturday, I found an abandoned egg whisk from my dorm. It was the perfect size and shape for the Dalek laser gun (See the reference image on the right)! I quickly cleaned it up and reshaped it to fit the Dalek's design. I also 3D printed two Ball-and-socket joints to hold the laser gun and plunger in place.

Next up is the eyestalk. The eyestalk is another iconic feature of the Dalek, often seen flashing blue light when the Dalek is in action. To create the eyestalk, I 3D printed a model modified based on an open source stl file using PLA filament and then installed a typical blue LED inside to achieve the flashing effect. The eyestalk was then mounted on top of the Dalek's head, completing the look.

The body of the Dalek was created using a combination of 3D printing and laser-cut cardboard. All the team members collaborated closely to ensure all parts fit together seamlessly. With Katrina and Guillermo, we were able to create a sturdy and lightweight internal structure(see in the middle picture) for the Dalek while on top of that Katherine(she is sitting behind the Dalek in the picture on the right~) also succeeded in creating the head dome and arm for laser gun and plunger with cardboard and kerfing design. At that stage, we had a solid foundation to build upon.

How to make a moving Dalek

The moving mechanism of the Dalek was achieved using a combination of step motors and a custom-built chassis. The team worked together to design a system that would allow the Dalek to glide smoothly across the floor based on human recognition through the camera module on ESP32S3.

Prototype phase

Claire H. and Claire W. took the lead on this subsystem, designing the chassis and integrating the motors with the Dalek's body. Since we were short on thick acrylic board, we first used cardboard to prototype the chassis and then later switched to acrylic for the final version. And because the chassis needed to hold all the drive components, we had to carefully measure and adjust the design to ensure everything fit together properly. A failed assembly example is shown below (there's no way to screw the wheel to the base as on the left so that we had to redesign another bracket holder as on the right):

After several iterations and adjustments, we were able to create a functional chassis that allowed the Dalek to move smoothly and respond to commands from the ESP32S3. Also thanks to Eghosa and Quentin's help working on the drive control, we were able to achieve precise control over the Dalek's movements. The Flask server is written in Python and run from a laptop, and the ESP32 communicates with it remotely through Wifi and a flashed Arduino sketch. That Arduino sketch uses SerCAT commands to drive the motors. See more details on our Gitlab repo.

Final Assembly

When all the chassis design was finalized and tested, we proceeded to cut the thick acrylic sheet for the final chassis (The reason why we chose to use a thick one is mostly because we hope the heavier base would improve stability and reduce vibrations during movement). But this thick acrylic board seems to be so ancient that we had to team up just to peel off the top film.

While waiting for the final assembly to complete, I worked on the voice system of the Dalek with Hayley's help based on the DFPlayer Mini with example code in the lecture for audio output. I set the audio to play in a loop and Hayley also milled a PCB for this output system.

Finally, after all the subsystems were ready, we assembled everything together. The final Dalek was a success, with all components working together seamlessly. The Dalek was able to move smoothly across the floor, respond to commands from the ESP32S3, and even emit its iconic "Exterminate!" sound effect. On the left is the video of testing the "following" mode and on the right is the video of testing the "stopping" mode:

Overall, building the Dalek was a challenging but rewarding experience. The team worked together to overcome obstacles and create a functional and impressive machine that captured the essence of the iconic Doctor Who villain. Though I'm not on the team for Doomscrolling, here's the link to that part by our team member Saleem, Kudos to their work on the Swiper & Tapping Automation!

Other Notes

• First, my heartfelt thanks to my teammates for their support and collaboration throughout this project. Also, I want to acknowledge the invaluable contributions of our mentors and instructors Anthony, Quentin, Jake and Jesse.
• We definitely killed a bunch of brilliant ideas before settled on building a Doomscrolling Dalek for this machine week, please see here if you would like some inspirations and ideas for future projects.

~A few more things I wanted to share about the Daleks and my thoughts on its story~

As Neil mentioned in class about the best doctor who (in his view) should be the fourth doctor by Tom Baker, there has been a classic moment in the episode "Genesis of the Daleks" where the Doctor is faced with a moral dilemma when he couldn't decide whether to exterminate the Daleks before they could become a threat to the universe.