FREDDY is a device that facilitates fretting and chord progressions for electric and acoustic guitar players with ranging abilities. This assistive device was developed to encourage a proactive approach to mobility through music-making.
Opportunity & Research
Participation in music-related activities enhances physical, mental, and social wellbeing. However, playing most musical instruments requires a certain level of physical ability. String instruments such as the guitar require dexterity, precision, and strength. Callusing on the fingertips is often developed due to the hardness of the strings.
This can be difficult to accomplish when people experience changes in their physical mobility. Of the many conditions and symptoms that can affect one’s ability to make music, many relate to aging. Aging brings about many physical and social changes and challenges. Common conditions that affect one’s ability and willingness to make music include arthritis and multiple sclerosis.
A decline in physical ability is often a determining factor in the reduction of participation in music-related activities over time. A proactive approach to encouraging the adoption and continuation of participation in music-related activities optimizes the short- and long-term benefits.
The Device
This assistive device was developed to facilitate guitar-playing for anyone who may be experiencing challenges with mobility that affect their guitar-playing.
The device consists of two main components:
The first is the playing module, which is the main interaction device. This module consists of an offset “neck”, where the user plays as they would without the device–the difference is that the elasticated strings require minimal force to press down. Capacitive sensors on this offset fretboard translate the signals to solenoids, which press the guitar strings down.
The second component is the bracket mounting system, which secures the playing module in place without damaging or altering the guitar. This bracket also allows users to slide the playing module back and forth to hit notes between frets 1 through 6 or 7 (depending on the guitar model).
Bracket mounting system component
Module component
The Setup
The device must first be mounted on the user’s guitar neck. The internal bracket system allows for the device to be used on most standard-sized guitar necks. The steps to set up the device are shown below. Once the device is set up, it can be kept on the neck even when stored.
Bracket assembly steps
Technology
This device utilizes capacitive touch on the offset neck module, which allows users to press down the strings with much less strength. These send signals to the PCB, which tells which push-pull solenoids to press down which guitar string. The ridges along the sides of the offset neck provide the user with better control of the module as it slides along the neck.
Push-pull solenoid pins
Control ridges for comfort and control when sliding the module up and down the neck
Modes: Mode 1
Once the device is set up, the user must turn it on via the power button. They must then choose the mode. To adapt to varying abilities, the device has two modes.
The first mode (automatic when turned on) allows the user to play on the device as they would on a traditional guitar, but by pressing down on the strings of the offset neck and strumming or plucking the strings with their other hand.
Power and Mode buttons
Soft, flexible nylon strings
Modes: Mode 2
The second mode allows the user to play a full chord by simply pressing the root note of the chord. Once this root note is pressed, it activates the other notes needed to complete the chord. For example, an A chord requires 3 separate notes to be held down. This mode allows the user to only press down one note–the root note, an A–to achieve a full chord. The chip on the PCB is programmed to recognize the root notes of common chords. This can be used by a user with reduced mobility, a learner who can not or is not comfortable formulating and/ or pressing down on chords, or anyone who would like assistance.
Mode 2 input: "A" note (root note of "A" chord)
Mode 2 output: "A" chord (3 notes pushed down by solenoids)
The Final Form
Bottom side view of assembled device (without guitar)
Top side view of assembled device (without guitar)
Bottom view of device
Side view of device with USB-C charging port and interaction buttons
Top view of device
Mounting bracket screw with knob resembling guitar tuning knobs
Components
THE DESIGN PROCESS
Survey Results
A Google Forms survey titled "Mobility Through Music-Making" was conducted from November to December 2021. A total of 84 people responded to the survey's 14 questions. A summary of the results is pictured below.
Prototypes & Testing
Below is a progression of prototypes that were developed throughout the design process.
Prototype 1, foam core
Prototype 1, foam core
Prototype 1, foam core
First sketch iterations
First sketch iterations
First sketch iterations
Prototype 2, foam core and cardboard
Prototype 2, foam core and cardboard
Prototype 2, foam core and cardboard
Prototype 2, foam core and cardboard
Meccano bracket prototype, front view
Meccano bracket prototype, side view
Meccano bracket prototype, back view
Meccano bracket prototype, Velcro strap
Initial sketches showing internal bracket mechanism that tightens around varying neck widths
Meccano bracket prototype, neutral position
Meccano bracket prototype, fitted position
Linear actuator and Arduino testing
Linear actuator and Arduino testing (neutral/ off)
Linear actuator and Arduino testing (activated/ pressed)
Functional linear actuator in first housing prorotype
Second version of the functional linear actuator in first housing prorotype
Sliding mechanism
The Visual Model: Process
This well-loved guitar was kindly gifted to me by Jerome at Glebe Guitar Repair
The guitar neck was cut off for the visual model (cut by Walter, SID shop technician)
Cut neck with mounting board
Guitar head, BEFORE
Guitar head, AFTER cleaning, sanding, and painting
Mechanical components removed from guitar head
Guitar neck, BEFORE
Guitar neck, AFTER cleaning, sanding, and oiling
3D printed parts on plate with supports (blue)
Removing the supports (blue) from the 3D printed parts
3D printed module with spackling for reinforcement
Sanded, filled, and painted module with bearings
All prototypes created throughout the course of this project
Work station with prototypes, sketches, and model
The Final Visual Model
Final visual model model, front angled view
Final visual model model, side view
Final visual model model, back view
Final visual model model, front view
Final visual model model, angled detail module view
Final visual model model, angled detailed top view
Final visual model model, detailed top view with actuator pins
