Flamel’s Apprentice

The Flamel's Apprentice is an alchemical piggy bank that explores themes of investment and return. The bank can only store one coin and will dispense it when a new coin is banked. When placed in a public space a user will be able to insert a coin and be awarded with another coin.

Since the box is opaque there is no way to evaluate the value held within, leaving a user with three possible outcomes for their investment: breaking even, losing, or gaining money. Put simply, the machine accepts coin (A) and dispenses a coin (B), where A becomes B for the next A.

The mechanisms, which is built through inclined planes, a photo interrupter, and solenoid, are condensed and hidden within a small form factor to trick the viewer into believing that the input coin has transformed into some other coin.

Will your gold become lead or something other metal? Insert a coin and find out!

Mechanism:

Arduino

Photo Interrupter

Solenoid

Resistor

Diode

Transistor

Passive Buzzer

Clear Acrylic

7x M2.5 Nuts

7x M2.5 14mm Screws

Coins

Box Encasing:

Plywood

Our initial ideas was a cabinet of curiosities with a single drawer which explores the idea of alchemy; in order to obtain an object, something of equal value must be exchanged. Our ‘useless machine’, in this case, simply does not follow this vital rule, as the coin that is produced is not guaranteed to be of the same value. Perhaps, our "useless machine" will forever be just an apprentice...

We settled on the idea of a coin swap and began iterating on designs to understand what components we would need to build such a device.

After sketching identified three parts to the design:

1. Input = knowing when a coin was inserted. 
2. Output = dispensing a coin.  
3. Mitigation = something to the timing and path of the previous steps 

The components that settled on to serve each design element includes a Photo Interrupter, which detects the input coin A once it travels through the entrance passage, a Solenoid to launch out output coin B from the storage cubby, and a Rail system to control the fall and speed of the coins so that the illusion of equivalent exchange is convincing. The system also allows time for the Arduino to complete any time delays between the components' communication. 

To allow the user to know when the alchemical exchange is processed through the machine, a buzzer playing the classic Mario Brothers coin sound effect is played just as the coin exists.

The first prototype was proof of concept, and as most projects in this course, the mechanism completely failed.

We identified multiple issues including: overall size of the mechanism, the incorrect illusion delay between coin A and coin b's respective drops, the position of the photo interrupter in relation to the solenoid's position, the differing speeds of coins depending on their size and weight, the friction relation between the system's acrylic and metal coins, and the solenoid's lever strength.

However, this prototype proved that our parts would fulfill the main functions of steps 1 (Input) and 2(Output) after modifying the design. We decided to clear acrylic as our main material and screw it in place to allow us to see the coin's travel path and for ease of assembly.  

Prototype 2.0 worked much better, addressing the issues in the Input and Output design portions. However, the Mitigation portion required further tweaking.

The design failed to catch and dispense the coins consistently, due to unforeseen aspect of the coin's bounce as it travels down the path, diverging out of the dedicated storage cubby. We tried resolving this issue by overlaying the rail system with rubber, to dampen the coins fall between the slopes. This was unsuccessful as the larger coins (loonies and toonies) often lodged in the narrower curves, varying the timed delay. Unrelated troubleshooting includes increasing the holes for the screws marginally larger.

It was determined that the rails system needed to be redesigned to further slow the coins and would require a longer fall distance. This was done through a 30° zig-zag rails system rather than the original sloped system, which allows all coins to follow an optimal path.

On our third iteration, the mechanism worked perfectly!

To establish that the exchange is complete, we incorporated a buzzer that follows a different delay than the solenoid once the Photo Interrupter is triggered.

We wanted this mechanism to be kept a secret, as most alchemy texts are. Therefore, we designed an encasing for the machine that reveals nothing of the useless alchemy that is occurring. The box would double as a housing compartment for our Arduino and breadboard components.

We went through multiple iterations including size and the position of which the Arduino mechanism sits within it.

Flamel's Apprentice , coming to stores near you!

reflect on the process and describe what worked well and what did not. What did you learn in the process? Were there parts of your machine that behaved differently from what you expected?"

The Arduino coding went very well, we faced no issues with rigging the setup and slowly combining our solenoid code and pitches code together. The first prototype, while it had its issues, was very successful in understanding where we can troubleshoot.

What did not work well was incorporating the Arduino setup into the encasing. Earlier iterations would have the Output coin lodge at the bottom, ruining the alchemical illusion. While the current final design functions perfectly, next steps to this project includes pushing the box design further. Perhaps playing with materiality and cosmetics, to really sell the idea.

Through the process of this project, we learnt a lot about materiality. The hardest obstacle we faced was controlling the coin's speed through the system. The acceleration of the coin drop differed with the material we chose to create the prototype with, as well as the slope of the system. Cardboard was unreliable, slowing the coin excessively and rubber lining diverged from the curved travel path of the coin which caused the solenoid to prematurely release. For this projects size and function, we found that Acrylic with the zigzag system to control acceleration worked best.

Next steps perhaps include redesigning the encasing to seamlessly include the mechanism as a spectacle, an interactive art installation of a sort. Another step could be designing the mechanism to have two or more channels, to push the probability of the value of the output coin. Cosmetically, perhaps adding an LCD screen to illustrate an illusion to accompany the buzzer is another option to further explore.

However, we are proud of all the technical and mechanical aspects that we concluded this project with. It was an enjoyable assignment and we look forward to expand on the illusion element in our final project.