TThis project proposes an alternative method of digital fabrication based on the dissolution of materials using abrasive liquids. While identifying suitable, low-impact, and non-toxic materials is a critical and extensive research topic on its own—and essential for validating the project's long-term feasibility and environmental relevance—this initial stage will focus primarily on developing the mechanical and electronic aspects of the system. The aim is to explore and understand the operational boundaries and potential of a liquid-based subtractive machine, investigating how controlled fluid dynamics can serve as a precise and programmable tool for material removal. This approach shifts the paradigm of fabrication away from traditional mechanical or thermal methods, opening a new experimental path that merges chemistry, engineering, and digital design.
Further development stages will include material testing and environmental evaluation, but for now, the priority is to build a working prototype that allows for iterative testing, learning, and refinement of the core subtractive process.
It is difficult to find projects that are very close to the one I am proposing, or even ones that yield similar results. What I appreciate is that it fits within a current of non-productive fabrication—it feels defiant and resistant. However, as part of the exploration, it is important to build bridges with examples that engage in more iterative and less clearly defined acts of subtraction. Among them, Michael Hansmeyer stands out. His projects speculate on voids reminiscent of caverns and surfaces shaped by time. Likewise, there are technical precedents such as acid etching used for sculpting metallic plates, which operate through gradual, subtractive processes.
TThe first mechanical concept of the project embraces lightness as a core design principle, replacing the traditional Y-axis with a wheel-based system that allows the machine to move endlessly across the chosen material. More than a functional gesture, this setup creates a playful tension between mechanization as an act of precision and a more spontaneous, ludic approach. The wheels support a gantry structure through which the X-axis moves, and mounted on this bridge is the toolhead, responsible for ejecting the abrasive liquid. Initially conceived as a self-contained autonomous machine, it could eventually evolve into a battery-powered mobile system. For mechanical motion, a key reference is the Creality CR-30 3D printer, whose conveyor belt-style print bed enables theoretically infinite movement along one axis. For liquid ejection, the design takes inspiration from micropipettes used in medical laboratories, which deliver precise quantities of liquid to targeted points with high accuracy.
The objective of this week is to establish the basic tools—both in terms of materials and knowledge—needed to successfully carry out the development of the final project. To achieve this, we will set certain guidelines starting from the project's concept up to its current stage of development.
To select the best set of components and the necessary knowledge for the project, it is proposed to explain how the device works.
The project was modeled at the component level for fabrication and was entirely designed in Rhinoceros.
The functional process of the project is explained in the following diagram.
The PCB design was developed in the electronics section of Autodesk Fusion.
PCB Fusion File
The final project consists of a Cartesian machine capable of dispensing corrosive liquids, such as thinner, that can dissolve materials like polystyrene to create a subtractive fabrication technique with artistic finishes.
The following diagram demonstrates the knowledge applied at each stage of the project's conception, fabrication, and programming process.
It is a portable Cartesian device designed to eject various liquids with the intention of becoming a subtractive manufacturing method that does not rely on force, but rather uses chemical reaction as the agent for material removal.
The closest precedents of a portable CNC can probably be found in the Shaper Origin, a wood machining tool that, through a camera and screen, can guide the cutting path. However, there is no version that combines these properties of automation or assisted material subtraction with the ejection systems found in bioprinters. This is where the advantage of 'the Machine that Cries' comes into play.
"I will design a lightweight and portable casing for a transmission system based on smooth rods and belts, which enables the movement of a head coordinated by two stepper motors. Using a servo motor in a remote ejection system, it allows the liquid to be dispensed onto the surface.
I will use two Step Motor Drivers, two NEMA 17 stepper motors, an SG-20 servo motor, a Seeed XIAO, a 12V 10A power supply, a voltage regulator and four capacitors, along with a system of belts and smooth rods.
The Seeed XIAO microcontroller and some components, such as the fiberglass PCB base and pin headers, are part of the equipment provided by the university. The rest of the components were purchased privately.
Approximately $75 was spent on electronics, another $40 on mechanical parts, and around $25 on the fabrication of components, resulting in a total investment of $140.
The containers for electronic components, such as the printer case (which will be 3D printed) and the power supply enclosure (CNC machined), will be fabricated. Likewise, the machined plate that organizes the stepper motor drivers will also be manufactured by me.
Digital fabrication methods will be used, such as 3D printing, CNC machining in acrylic, and CNC machining for the fiberglass plate used in the electronics.
Extensive research must be conducted on the material aspect. The interaction between thinner and polystyrene is highly toxic and potentially polluting. While the mechanism is clever and highly expressive, it would be ideal to replace it with organic materials such as formic acid or similar substances applied to naturally sourced materials.
It is necessary to evaluate the coherence between the proposed subtractive manufacturing method and portability. Iterations can be made to improve performance.
The electronics and manufacturing parts are already completed; only the programming and testing stages remain
All the fabrication work (physical, tangible, so to speak) has been completed, but the programming part has only remained in the research phase, looking for a G-code firmware suitable for the memory space of the Seeed XIAO.
It is urgently necessary to determine which firmware is the most suitable. From what has been read so far, Tiny-G will be chosen; however, learning to coordinate servomotors with stepper motors for the project is still pending.
The project can be completed in its first iteration and open the field for experimentation with other automation methods for this subtractive manufacturing system.
his exercise has been very helpful for sharpening my knowledge of 3D modeling oriented toward mechanical systems. Additionally, I have learned a lot about the functioning of microcontrollers, from their design to their electrical operation. Finally, I have been exposed to less typical manufacturing methods which, although not used in this exercise, remain as possibilities for future iterations.