Introduction: Piano Pedal Pusher

Spinal cord injuries are a broad class of injuries that involve damage of the spinal cord which transmits signals to and from the brain. These injuries often result in limited motor function, making it difficult for the patient to move the muscles in their arms, hands, feet, and legs. The severity of these injuries can range from an inability to control their fingers or toes to a nearly full body paralysis. This can make it challenging for these individuals to complete daily tasks independently, such as brushing their teeth, writing, typing, and even playing music. The goal of this project is to design a device that will allow these individuals to independently play an instrument and produce music.

Three of the main competitors for this device are the Musical Glove, the Clarion, and the Jamboxx. The Musical Glove provides vibrations to the user’s hand which helps them regain function and sensation in their fingers. Patients had improvement in being able to play the piano and feeling everyday sensations. The Clarion is a device where patients can control a user interface that utilizes an eye tracking program to produce music digitally. The Jamboxx is another digital instrument which inputs the user’s breath to produce different notes.

Our goal with this project was to improve the experience of playing an existing device. We decided to focus on helping patients with limited range of motion in their legs to play music on the piano while utilizing pedals. The model works by signaling for motors to extend and retract cylinders which will push down pedals. The motors would be connected to an Arduino where each motor is connected to an associated button. When the button is pressed, the motor would rotate one way to push down the pedal and when the button is released, the cylinder would retract and allow the pedal to go back.

The current state of the device is a CAD file of the mechanism to which the motors would be attached. This mechanism would be 3D printed and attached above the pedals of a piano. The motors, buttons and Arduino to control it would still have to be implemented.

With the final model, when the user is playing the piano, they can press one of three buttons to push down a pedal on the piano.


For more information on the design requirements for this device, head to this link:


Step 1: Make the Base in CAD

Step 2: Make the Connector in CAD

Step 3: Make the Vertical Gear in CAD

Step 4: Make the Gear in CAD

Step 5: Make the Right Pedal in CAD

Step 6: Make the Middle Pedal in CAD

Step 7: Make the Left Pedal in CAD

Step 8: Make the Fastener in CAD

Step 9: Print the CAD Files

Set up your printer and 3D print the CAD parts files (attached below) with a durable material, such as the PLA filament recommended.

Step 10: Assemble the Parts

Clean off any support material from your 3D printed parts. Assemble the mechanism as shown.

Step 11: Attach the Assembly to the Piano

Attach the assembly right above the pedals, by taking off the connector, putting the rest of the assembly in place, and then putting the connector back.

Step 12: Attach the Motors

Attach three motors, one to each gear of the CAD parts.

Step 13: Connect the Motors to the Breadboard and Arduino

Connect the motors to a breadboard and an Arduino following


Step 14: Connect the Buttons to the Breadboard and Arduino

Connect three buttons to the breadboard and Arduino following

Step 15: ​Write the Code Connecting the Buttons and Motors

Write the code to associate each button to a corresponding motor. When the button is pushed, the motor should extend the cylinder. When the button is released, the motor should reverse direction and retract the cylinder.

Step 16: Safety

Since the device uses electronics, it should be kept dry and separated from potentially damaging liquids. Caution must also be taken to cover up exposed wires to avoid exposed current.

Step 17: Care and Maintenance

Move the device with caution and be sure to keep the device away from areas with high temperature (such as a heater or fireplace) as this will likely affect the function of the device. If the device needs to be cleaned this can be done with a disinfectant wipe or damp towel, but be sure to only clean the filament-based parts of the device and avoid getting any liquid on the electrical components as this could be dangerous. If there are any issues with the electrical components and they need to be replaced, exercise caution and be sure not to leave any exposed wires uncovered.

Step 18: Improvements and Extensions

Sensors can be added to the device to ensure that the motors do not move too violently to damage the mechanism or the piano. An alternative to having to push the button the whole time to keep the pedal down would be to push the button once to extent the cylinder and push it again to retract it. This would allow the user to play with both hands more and spend minimal time off the keys.

Step 19: Build Off This Project

If you want to adjust some settings on the CAD, or build off this project, just use the attached CAD files.

Step 20: References

Dolan, V. (2020, February 11). Musicians With Spinal Cord Injuries. Retrieved February 20, 2020, from

Georgia Tech Arts. (2016, October 7). Musical Glove Improves Sensation, Mobility for People with Spinal Cord Injury. Retrieved February 21, 2020, from

Jamboxx. (2020). Jamboxx. Retrieved February 19, 2020, from

Mauro, Terri. (2019, August 9). How to Know If Your Children Are on Track with Motor Skills. Verywell Family, Verywell Family. Retrieved February 22, 2020, from 3107058.

Open Up Music Team. (2018, October 25). The Clarion. Retrieved February 21, 2020, from

Shepard Center. (2020). Spinal Cord Injury Information. Retrieved February 21, 2020, from