Group 1 2012 Gate 1

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Gate 1 is a primary assessment of the product (an upright piano) which will be dissected and analyzed in future gates. Before dissecting, we will assess the product's history, superficial construction and usage. In addition, we will assign roles to members of Group 1 and establish a plan for future work.

Contents

Project Management

Work Proposal

Note the flathead screws on the middle left of the image, and the string pins across the top of the piano (Fig 1).

Upon initial inspection, it appears that the majority of the piano is held together with simple flathead screws. The one major exception to this trend is the piano string pegs, which are rounded squares and require a tuning hammer to remove. Based on these observations, it seems likely that all that is necessary for the deconstruction of the piano is several different sizes of flathead screwdriver,and a tuning hammer which we can acquire from UB's piano technician. From the visible complexity of the piano (Fig 1), it should not take more than several hours to fully deconstruct. That said, it is unlikely we will choose to remove the plate (the metal frame the strings are attached to) or most of the strings from whatever remains of the piano. We must also be careful not to remove any of the load bearing sections of the wooden frame. In addition, the most mechanically complex and dense section of the piano, the action, will be easy to remove but hard to deconstruct, and we may opt to take apart our spare action in lieu of the piano's actual action.

Timeline

Due to scheduling conflicts, meeting the weekend of the 13th is not possible. Group members should perform preliminary research about pianos before the meeting to familiarize themselves with piano function if necessary.

Sunday 10/21-Dissection. Complete disassembly with documentation of the piano. After the piano is completely dissected, the project leader will set up a rough outline on the Gate 2 page to allow members to edit their assigned sections.

Monday 10/22-Meet after MAE 277 lecture to discuss progress. Group members should have preliminary information on the wiki.

Wednesday 10/24-Meet after MAE 277 lecture. Group members should have their section of the wiki complete and ready for final formatting.

Friday10/26-Wiki should be ready for submission.

Dissection Plan

  • Dissection will take place in Matt Swenson's room, the current location of the piano.
  • Various group members must bring screwdrivers and other tools to the meeting.
  • If we decide to take out the strings, we need to borrow a tuning hammer from UB's piano technician before the meeting.
  • Document the dissection process in a list of steps.
  • Photograph each part immediately before and after taking it out of the piano.
  • Store parts with their associated mounting hardware (screws, etc.)

Group Capabilities

As a whole, our group is technically qualified to deconstruct the piano. Chris Chungbin, our technical expert, is very well versed in the inner workings of the piano keys and pianos in general, and several other members of the group have had prior experience taking apart complicated machines such as car or motorcycle engines. Several of us have had 2D and 3D modeling experience.

To date, our group's largest flaws do not appear to be technical in nature; it has proven difficult to get all of the group together in one place to work on the project. In acquiring the piano, for example, many logistical problems arose, ranging from contact information to assigned tasks. In future gates we will need a more strict schedule and task allocation structure.

Management Proposal

Our current plan is to meet every weekend as needed to work on the piano and project gates, and to have progress updates after every MAE 277 class to determine how progress on assigned portions of project gates are going, and if a general weekend meeting is required that week. General weekend meetings will occur in Matt Swenson's room, as that is where the piano is located.

Project Roles

Project Leader-Matt Swenson-Primary responsibility is keeping other group members on task during meetings. Finalizes meeting times. Assures that project and individual assignment deadlines are met. Edits submissions to ensure quality standards are met. Reviews final formatting.

Technical Expert-Chris Chungbin-Has a high degree of understanding of internal components of piano. Should understand theory and practice of most if not all components of the piano and their function as they relate to the operation of the entire piano. Takes the lead on deconstruction of piano.

Communication Liaison-Sam Kielar-Coordinates group meetings. Ensures all group members know when and where the group will meet next, and any relevant general information. Communication with group members will be through text or email outside of meetings. communication with professors will be through email, office hours, or after class. Point of contact for all group members, and professor.

Technical Assistant-Sam Kriever, Matt O'Connor-Assists the technical expert in deconstructing the piano. Assigned components or subsystems to understand in function and interactions. Contributes to write-ups of project gates.

Product Assessment

Development

Note manufacture information in the top right corner of the cast-iron plate.
  • This upright piano model was developed during the early 1960's by Starr in Richmond, Indiana.
    • The date of manufacture is April 28th, 1962 as noted inside the piano case.
  • The key economic concerns at the time of development mainly revolved around the common family, as this model was made for home use.
    • The price of the piano had to be within an acceptable range for homeowners, and thus it had a rougher design and cheaper manufacturing costs than a professional piano at the time.
    • Although exact prices were impossible to verify, the rough interior finish quality of parts of the action suggest cost-reduction.
  • The main global concerns of the time included the American musical culture, as pianos have been a significant part of American music. Another cultural influence would include furniture architecture, which would affect the structural and visual design of the piano. The front supports of the piano include turned sections to improve form.
  • This piano was developed and manufactured in Richmond, Indiana. The plate inside the piano shows the production location. This model was intended to be used and sold in the United States.
  • A piano is intended to have an entertaining and artistic impact on consumers and society as a whole.

Usage

  • The primary use of a piano is for entertainment and leisurely activity, based on observations of pianos in homes or public places and of our piano.
  • This piano is an upright model, and is meant for home use. [1]
  • A piano's job is to provide musical entertainment, whether it be for home recreation, or professional performances.

Energy

The product's main function is to convert work on the keys into sound energy. Work from the player's fingers transfers through a series of levers in the action to the hammer which transfers energy to the string. A benefit of this system is that reducing force on the key reduces the energy of the string. The basic formula for the transfer of energy between the player's finger and the hammer is as follows:

W=∆KE

Consequently,

F•d=mv²/2 [2]

Since the distance that the key travels and the mass of the hammer are constants, an increase of force gives the hammer more speed.

Once the hammer strikes the string, some energy is transfered into the potential energy of stretching and deflecting the string. The string begins oscillating, or transferring energy to motion, then back to stretching the string repeatedly. The formula for the energy of a vibrating string is

E=mω²A² [3]

where A is the amplitude and ω was the angular frequency.

The motions of the string create pressure waves in the surrounding air which listeners perceive as sound. The intensity of the sound corresponds to the energy from the hammer because sound intensity depends on the amplitude of the oscillations.

Complexity

The piano is composed of several hundred components. However, each individual component is relatively simple, ranging from a basic lever to a push-rod to a tensioned wire. Interaction between the components is the primary source of the complexity in this product since inputs from different components can add or remove functions of other inputs. (See fig 2 for a view of an action and keys.)

This is a preliminary list of components:

  1. Case-exterior of piano
  2. Keys
  3. Hammers
  4. Mutes
  5. Action-transmits motion to hammers and mutes
  6. Pedals

The piano's mechanism is housed in a wooden case. The front of the case houses the keyboard near the top and two pedals near the bottom. The top and front panels of the case can be opened for maintenance and it is through these that we performed most of the initial analysis. Through the top lid one can see the back side of the key levers and the corresponding hammers and mutes. The front panel opens to reveal the pedal mechanism as well as a cast-iron frame that holds the strings.

Three keys depressed. Note the hammers in a half-raised position and the mutes removed from the strings (Fig 2.)

Upon pressing a key, the back end of the key lever raises a metal pull-rod that leads under the visible mechanism. The pull-rod operates both the mute and the hammer, raising the mute off the string and striking the hammer into the string simultaneously. As long as the key remains pressed, the hammer is held in a half-struck position and the mute remains off the string. Once the player releases the key, the hammer falls back against a wooden rest and the mute presses back onto the string, consequently stoping the sound.

The right pedal operates a secondary lever that raises a push-rod along the side of the case. The push rod raises the mutes off the strings even if keys are not depressed. When this pedal is depressed, every note that the player strikes will continue to sound after the key is released.

The left pedal operates a push-rod alongside the mechanism of the right pedal. When the left pedal is depressed, the wooden rest against which the hammers lay moves closer to the strings. This affects the sound by reducing the intensity of the sound.

Material

There are only a few materials that are clearly visible. Wood makes up the majority of the frame and inner workings, but there is a large cast iron frame at the rear of the piano. The strings are high-tension steel and the keys are covered in plastic. While we cannot be sure without fully disassembling the piano, it can be inferred that rubber or felt is used in some areas of the action.

Wood is the primary material because it is cheap, easy to shape in orthogonal shapes, and easy to finish in many ways. The cast iron plate is necessary to withstand the tension in over 100 steel wires without deforming. Steel was used in the wires for its flexibility and for the manufacturing process of wires.

Interaction

The piano's inputs are the pedals and keyboard.

In order to interface with a piano, the user hits the keys on the piano to create the desired notes. The user also works the pedals to modify the sound the piano produces. The user may also need to do maintenance on the piano periodically.

The interface is fairly intuitive. It is easy to figure out that hitting a key produces a note and with a minor amount of testing one should able to learn which pitch is associated with each key. The keys are also arranged in a logical order of low notes on the left to high notes on the right in a repeating pattern of seven white and eight black keys.

Even though the keyboard is intuitive, it is difficult to use because music demands wide ranges of notes and simultaneous notes that are difficult to reach.

For an average user, regular maintenance involves exterior or interior cleaning as necessary, and a tuning every six months to a year. Cleaning a piano is easy and can be done with common household items with little work. Tuning a piano, however, requires some knowledge and specialized tools such as a tuning hammer and electric tuning device, which gives it some degree of difficulty.

Alternatives

The alternatives to a piano are the electronic keyboard and software packages that can mimic a piano (as well as other instruments) for recording purposes. Keyboards and software packages are both much more portable than a piano and both can create a much wider range of sounds than a piano can. They are also, for the most part, less expensive than a quality piano and take up less space when stored.

Neither the electronic keyboard nor the software package create the true piano sound though. The best either of the two can do is create a digitized version of a piano sound, which, however accurate it may be, is not the real thing. The software package is also not an actual instrument, so users interact with it in a much different way and could not perform with it. Professional or amateur pianists also tend to prefer the feel of a physical, mechanical key to the electric switch of the alternatives.

The piano and its alternatives can be obtained inexpensively if one does not care about the quality. At lower prices, the keyboard may be similar in sound quality to the piano, and take up less space. The best-sounding piano cost upwards of two thousand dollars, while a high-quality keyboard costs around two hundred. A professional mixing program costs about two hundred as well. However, a low-end piano, new or used, can vary in price from under one-hundred dollars to several hundred. An electric keyboard is easily less than one-hundred and open-source or freeware sound mixing programs can completely eliminate the economic drawbacks because many are sold for free.

Quality pianos are much, much more expensive and bulky than its alternatives, but the sound quality and user interface can be superior.

Alternative Pros Cons
Electric Keyboard
  • Low to medium cost
  • Multiple instrument sounds possible
  • Less maintenance
  • Less space needed
  • Slightly more portable
  • Digitized sound may be unrealistic
  • Tactile response is poor compared to physical action
  • Requires electricity
Software Package
  • Low to medium cost
  • Nearly no space needed
  • Nearly infinite sounds possible
  • Not limited by keyboard interface
  • Not for real-time performance
  • Requires computer