Gearing Torque

Force on pedal = 13 lbf(-13 lbf)(8”) – B(2.5”) =0 ⇾ B = -41.6 lbf(-41.6 lbf)(10.5”) + (F)(16.5”)= 0 ⇾ F = 26.47 lbf

Force Required to Lift Mutes

For Key A4: f = frequency =440 HzL = length = 15 inD= diameter of string =0.039 = density =0.282 lb/in^3

Calculating String Tensions

Frequency of each string needs to be analyzedElectret microphone will transform in into ac signal FFT performed to analyze occurrences of each frequencyGoal is to get voltage to rise linearly with frequency

Lead Screw Torque

Frequency of Strings

r = Ratiop = Octavecents = 1200 equal intervalsPn = Frequency of noten = piano key number (from 1 – 88)Pa = Reference Frequency (A)

To find the frequency of the 40th note (indicated by a blue key) using the 49th note (shown as a yellow key) as a reference

Step 1: Motors move the tuning mechanism along rails to the desired tuning peg, engaging it by means of a socket head attached to a motor shaft

Step 2: A solenoid lifts the mute lever, raising felt mutes off of the strings and allowing them to resonate

Step 4: The motor attached to the socket head turns the peg in the direction required to correct the pitch

Step 5: The mutes are released and the system moves on to the next peg

Step 3: A small solenoid strikes the associated string; its pitch is determined via Digital Signal Processing

Machine StartPeg Location

ProcessMute Released

String Striking Process

Frequency Determined

Frequency Correct?

String # Set to x=x+1

Last String?Machine Stop

No

No

Sharp or Flat?

Peg Turned Clockwise

Flat

Peg Turned Counter-

ClockwiseSharp

Mute Engaged

String Location Process

Yes

Yes

Peg Engaged

Peg locator process initiated

Coordinates for String # are read

X-Motor Moves Tuner to

X-Coordinate

Y-Motor Moves Tuner to

Y-Coordinate

Peg Location Complete

String Location Process Started

Coordinates for String # are read

θ-Motor moves Striker to position at angle θ from

corresponding peg

String Location Complete

The EasyKeys Team Mechanical Engineers:

- Tom Oliphant- Victoria Theese

Electrical Engineers:- Patrick Rienzo- Russell Jones- Kieran Walters

Faculty Advisor:- Professor Charles Geraldi

String Engagement

Process Started

Socket lowered onto tuning peg

Spring disengaged?

Process Ended

Yes

Motor Turned

No

Peg Location System

String Location System

Peg Engagement System

Legend:1. Track for Tuning / Striking Mechanisms2. Frequency Detection Subsystem3. Mute Lifting Subsystem4. Microcontroller

Overall System

The goal of this project is to create a device capable of tuning a piano without human aid

Mechanical Objectives:Remove mutesMove between pegs and stringsDiscreetly integrate into piano

Electrical Objectives:Design power circuitsImplement pitch-determination systemDevelop control algorithm Drawings made for all

machined parts (M-XX ): X-, Y-, and Z-axis

rails X-, Y-, and Z-axis rail

supports Rail slides Support plates Motor mount platesPurchased Parts (P-XX on drawing):

Lead screwsMcMaster-Carr

Theta motor Oriental motors - P/N 3TK6GN-AW2U

X,Y, and Z motorsOriental Motors – P/N SMK237A-A

Finalized Design

Final Drawing of System

Stronger material required for rails Smaller motors required Position of the tuning socket must be adjustable in

order to to reach all the pegs

File patent application Design market-ready version

Enable the system to reach all of the pegsUtilize more suitable materials and motors Increase speedDecrease noiseDecrease sizeDesign housing for the systemMake the system removable

“Ideally, acoustics should be tuned on a weekly basis, and right before all performances as well. However, tuning is expensive and time consuming (…) Generally, the pianos (in the music room at Stevens) get one tuning per semester. This is just not enough, and yet, it's what the program can afford.” -Bethany Reeves, Director, Stevens Choir

A single professional tuning takes 60-90 minutes and costs over $100. The average piano needs to be tuned twice per year, but pianos in recording studios may need to be tuned a few times each week.

Verified correct function of individual components Ensured smooth movement over entire range-of-

motion Tested frequency determination subsystem