The mechanism of translating the bridge in order to manipulate the tension and pitch of the strings will be analyzed to determine the most effective method. The previously proposed idea using gears will be tested against a solution using a lever and one using a small motor.
Each idea is not fully realized and may not be fully functional, but is considered in order to determine the most effective strategy. Tuning stability and the factors involved will be ignored. Springs attached to the back of the bridge and strings attached to the front will balance the forces in the same axis and hold the bridge in equilibrium. Forces applied by each module will translate the bridge along the same axis, changing the tension and pitch of the strings. For the power equations, two of several forces will be shown, but this is only to show that movement can happen in two different directions and are not acting at the same time.
Each strategy is graded on a 1-5 scale, with 5 being the best, in each of the categories. Ease of Use is how comfortable and practical each design would perform in a time restricted, musical context. Manufacturability is how easily each design is produced and assembled. Musical Possibilities include the variety of different techniques that can be performed with each design.
Design 1 won because it would be the easiest to use and offer the most variety in a musical context.
The large dark gray piece is the base plate that everything is fixed to which is then fixed to the guitar. The lighter gray piece is the bridge, the small green pieces are the string saddles; these are what hold the ball end of the guitar strings. The underside of the bridge has a track cut into it for the large gears on the large axle to meet with to translate the bridge. The blue areas denote toothed gears.
The mechanism works by applying a torque to the long, thin bar to rotate the short cylinder with the bevel gear attached to the bottom. This bevel gear meets with the matching bevel gear on the end of the large axle. This causes the large axle to rotate about its axis. The large gears attached to the large axle meet with the underside of the bridge and apply the force to translate the bridge, thereby altering the tension and pitch of the strings.
An advantage of this module over the others is the amount of direct control the user would have. Being as manual and tightly connected as it is, the user would have very accurate control over the movements of the mechanism.
The darker green area denotes the pins that protrude below the base plate to meet with the lever. The red area denotes the lever used to apply a force to translate the bridge. The underside of the bridge also features smaller pins on the opposite side that ride inside the track cut into the base plate to prevent the force from the lever from applying a moment instead of only translational force.
This mechanism works by applying a torque to the long, thin bar to rotate the short cylinder with the lever attached to it about its vertical axis. This force is carried to the lever when it meets the pins on the underside of the bridge, then applying a force to translate the bridge to alter the tension and pitch of the strings.
This module would likely be more physically demanding to manipulate than the other modules. It would also likely have a dead zone where the lever does not fully contact the pins.
The dark blue area denotes a small motor that applies a torque to the large axle. The violet area denotes the place where the motor and the axle are connected. The large gears are used in the same way as previous modules to meet with the track cut into the underside of the bridge to translate the bridge and alter the tension and pitch of the strings. The bridge is not included in this assembly because no changes were made to the original design.
The long, thin bar is used to activate a switch that rotates the motor in a specified direction. Turning the bar clockwise will activate the motor to turn in a way to move the bridge forward, lessening the tension in the strings and lowering the pitch. Turning the bar counterclockwise will activate the motor to turn in a way to move the bridge backward, increasing the tension in the strings and raising the pitch.
This module would require the least physical effort to use because of the automation. It would also be the most difficult to use in a musical setting and would also require a motor with very specific dimensions and capabilities.
I learned more about the different types of gears there are and how they are used.
Brainstormin, Planning, and Research - 3/25/19 4:30pm - 11pm
CAD Models - 3/25/19 5pm - 7pm
Decision Matrix - 3/25/19 8pm - 8:30pm
Descriptions - 3/25/19 8pm - 9:30pm
Problem Statement - 3/25/19 8pm - 9:30pm
Assumptions - 3/25/19 8pm - 8:30pm
Power Equations - 3/25/19 10pm - 10:45pm
FRDPARRC - 3/25/19 7:30pm - 8pm
Gantt Chart - 3/25/19 7pm - 7:30pm
Coding - 3/25/19 11pm - 12am
Dawson Pauley: As of 3/26/2019 at about 12:04 am Dawson has not yet published the assignment.
Matthew Hestenes: It looks great. It is clear you put a lot of work into it. However, I do not see the download link to download the CAD files.