Group 1 2012 Gate 2 - Revision history

MAE 277 2012 - Group 1: /* Difficulty Scale */

2012-12-14T18:15:36Z

Difficulty Scale

MAE 277 2012 - Group 1: /* Steps */

2012-12-14T18:15:09Z

Steps

MAE 277 2012 - Group 1: /* Steps */

2012-12-14T18:14:16Z

Steps

Show changes

MAE 277 2012 - Group 1: /* Steps */

2012-12-14T18:11:42Z

Steps

MAE 277 2012 - Group 1: /* Difficulty Scale */

2012-12-14T18:09:09Z

Difficulty Scale

MAE 277 2012 - Group 1: /* Subsystem Interactions */

2012-12-14T10:55:23Z

Subsystem Interactions

MAE 277 2012 - Group 1: /* Subsystem List */

2012-12-14T10:33:26Z

Subsystem List

MAE 277 2012 - Group 1: /* Hammers */

2012-12-14T10:27:35Z

Hammers

MAE 277 2012 - Group 1: /* Subsystem List */

2012-12-14T10:26:26Z

Subsystem List

MAE 277 2012 - Group 1: /* Possible Corrective Action */

2012-12-14T10:10:43Z

Possible Corrective Action

@@ Line 17: / Line 17: @@
 As a general rule, no part of the piano is truly meant to be taken apart by a consumer. The top hatch lifts up to expose parts of the action, and the bottom baseboard can be removed fairly easily without tools, but other than that, everything requires the use of a screwdriver to remove. That said, a screwdriver is really the only tool actually needed to take the entire piano apart. Almost all of the piano, save for those structural sections which are laminated together, is held together by screws. This results in the physical difficulty of each step being both highly similar and remarkably low. This causes the main difficulties of every step to be caused more by required delicacy of handling of parts and the amount of thought that is involved in deciding which part to take apart and how to get at them.
 ===Difficulty Scale===
-The following is the difficulty scale we will use to describe the difficulty of each step outlined in the deconstruction in the piano. To allow for flexibility in actions taken in the steps, difficulty ratings will be given for each separate column, and then added together for a total difficulty rating. For instance, a step that requires one person to spend twenty minutes and has a moderate logic component would be denoted as "1-3-2" and "6" in the overall difficulty problem. Steps with equivalent overall difficulties are roughly equivalent in difficulty in real life.
+The following is the difficulty scale we will use to describe the difficulty of each step outlined in the deconstruction in the piano. To allow for flexibility in actions taken in the steps, difficulty ratings will be given for each separate column, and then added together for a total difficulty rating. For instance, a step that requires one person to spend twenty minutes and has a moderate logic component would be denoted as "1-3-2" and "6" in the overall difficulty column. Steps with equivalent overall difficulties are roughly equivalent in difficulty in real life.
 {|class="wikitable" style="text-align: center; color: black;
 |Scale #

@@ Line 82: / Line 82: @@
 |rowspan="2"|[[File:2012_Group_1_Picture_1.jpeg|200px]]
 |-
-|colspan="4"|There is a latch near the baseboard of the piano on the underside of the keys that holds the baseboard of the piano in. Flip it, and remove the baseboard.
+|colspan="5"|There is a latch near the baseboard of the piano on the underside of the keys that holds the baseboard of the piano in. Flip it, and remove the baseboard.
 |-
 |colspan="5"|
@@ Line 116: / Line 116: @@
 |rowspan="2"|[[File:2012_Group_1_Picture_6.jpeg|200px|]]
 |-
-|colspan="4"|This bar holds the keys in place, and must be taken off next. It was held in by evenly spaced screws along its length.
+|colspan="5"|This bar holds the keys in place, and must be taken off next. It was held in by evenly spaced screws along its length.
 |-
 |colspan="5"|

@@ Line 61: / Line 61: @@
 |'''Step Description'''
 |'''Tool Used'''
-|'''Difficulty Rating'''
+|colspan="2"|'''Difficulty Rating'''
+|
 |-
@@ Line 67: / Line 67: @@
 |Remove top hatch
 |Screwdriver
 |2-1-1
 |rowspan="2"|[[File:2012_Group_1_Picture_3.jpeg|200px]]
@@ Line 77: / Line 78: @@
 |Remove bottom baseboard
 |None
 |1-1-1
 |rowspan="2"|[[File:2012_Group_1_Picture_1.jpeg|200px]]
@@ Line 87: / Line 89: @@
 |Remove horizontal bar on top of sliding keyboard cover
 |Screwdriver
 |1-1-1
 |rowspan="2"|[[File:2012_Group_1_Picture_4.jpeg|200px|]]
@@ Line 98: / Line 101: @@
 |Remove keyboard cover
 |Screwdriver
 |2-1-1
 |rowspan="2"|[[File:2012_Group_1_Picture_5.jpeg|200px]]
@@ Line 108: / Line 112: @@
 |Remove Horizontal bar on top of keys
 |Screwdriver
 |1-1-1
 |rowspan="2"|[[File:2012_Group_1_Picture_6.jpeg|200px|]]
@@ Line 118: / Line 123: @@
 |Remove steel pull-rods from key-levers
 |None
 |2-2-2
 |rowspan="2"|[[File:2012_Group_1_Picture_9cropped.jpeg|200px]]
@@ Line 128: / Line 134: @@
 |Unscrew action bracket and lift out
 |Screwdriver
 |3-1-1
 |rowspan="2"|[[File:2012_Group_1_Picture_8.jpeg|200px]]
@@ Line 138: / Line 145: @@
 |Remove keys and key pin board
 |None
 |3-2-2
 |rowspan="2"|[[File:2012_Group_1_Picture_13.jpeg|200px|]]
@@ Line 147: / Line 155: @@
 |Remove key pin board
 |None
 |2-1-1
 |rowspan="2"|[[File:2012_Group_1_Picture_23.jpeg|200px]]
@@ Line 157: / Line 166: @@
 |Detach pedal levers from pedals
 |Wrench, pliers
 |1-1-1
 |rowspan="2"|[[File:2012_Group_1_Picture_20.jpeg|200px]]
@@ Line 167: / Line 177: @@
 |Remove pedal dowels
 |None
 |1-1-1
 |rowspan="2"|[[File:2012_Group_1_Picture_19.jpeg|200px|]]
@@ Line 177: / Line 188: @@
 |Detach pedal levers from piano floor
 |Screwdriver
 |1-1-1
 |rowspan="2"|[[File:2012_Group_1_Picture_38.jpeg|200px|]]
@@ Line 187: / Line 199: @@
 |Remove pedal hinges and remove axle from pedal
 |Screwdriver
 |1-1-2
 |rowspan="2"|[[File:2012_Group_1_Picture_21.jpeg|200px]]
@@ Line 197: / Line 210: @@
 |Unscrew pull-rod and associated lever
 |Screwdriver
 |1-1-3
 |rowspan="2"|[[File:2012_Group_1_Picture_35.jpeg|200px]]
@@ Line 207: / Line 221: @@
 |Unscrew hammer and remove
 |Screwdriver
 |1-1-3
 |rowspan="2"|[[File:2012_Group_1_Picture_37.jpeg|200px]]
@@ Line 217: / Line 232: @@
 |Unscrew mute
 |Screwdriver
 |1-1-2
 |rowspan="2"|[[File:2012_Group_1_Picture_35.jpeg|200px]]
@@ Line 227: / Line 243: @@
 |Unscrew the iron bracket on the end of the action
 |Screwdriver
 |2-2-2
 |rowspan="2"|[[File:2012_Group_1_Picture_30.jpeg|200px|]]
@@ Line 237: / Line 254: @@
 |Remove the una corda pedal bar
 |None
 |2-1-2
 |rowspan="2"|[[File:2012_Group_1_Picture_30.jpeg|200px]]
@@ Line 247: / Line 265: @@
 |Remove spring bar
 |Screwdriver
 |2-1-3
 |rowspan="2"|[[File:2012_Group_1_Picture_29.jpeg|200px]]
@@ Line 257: / Line 276: @@
 |Unscrew the mutes above the hinges of the sustain pedal bar
 |Screwdriver
 |1-3-3
 |rowspan="2"|[[File:2012_Group_1_Picture_32.jpeg|200px]]
@@ Line 267: / Line 287: @@
 |Unscrew the hinges of the sustain pedal bar
 |Screwdriver
 |1-1-1
 |rowspan="2"|[[File:2012_Group_1_Picture_33.jpeg|200px]]
@@ Line 277: / Line 298: @@
 |Pull sustain pedal bar out
 |None
 |1-1-1
 |rowspan="2"|[[File:2012_Group_1_Picture_36.jpeg|200px]]

@@ Line 17: / Line 17: @@
 As a general rule, no part of the piano is truly meant to be taken apart by a consumer. The top hatch lifts up to expose parts of the action, and the bottom baseboard can be removed fairly easily without tools, but other than that, everything requires the use of a screwdriver to remove. That said, a screwdriver is really the only tool actually needed to take the entire piano apart. Almost all of the piano, save for those structural sections which are laminated together, is held together by screws. This results in the physical difficulty of each step being both highly similar and remarkably low. This causes the main difficulties of every step to be caused more by required delicacy of handling of parts and the amount of thought that is involved in deciding which part to take apart and how to get at them.
 ===Difficulty Scale===
-The following is the difficulty scale we will use to describe the difficulty of each step outlined in the deconstruction in the piano. To allow for flexibility in actions taken in the steps, difficulty ratings will be given for each separate column. For instance, a step that requires one person to spend twenty minutes and has a moderate logic component would be denoted as "1-3-2".
+The following is the difficulty scale we will use to describe the difficulty of each step outlined in the deconstruction in the piano. To allow for flexibility in actions taken in the steps, difficulty ratings will be given for each separate column, and then added together for a total difficulty rating. For instance, a step that requires one person to spend twenty minutes and has a moderate logic component would be denoted as "1-3-2" and "6" in the overall difficulty problem. Steps with equivalent overall difficulties are roughly equivalent in difficulty in real life.
 {|class="wikitable" style="text-align: center; color: black;
 |Scale #

@@ Line 314: / Line 314: @@
 ===Subsystem Interactions===
 The action subsystem is a main hub of system input and output. It receives input signals and energy from the keys and pedals and outputs energy and signals to the strings and cast-iron frame.
 ====Primary Input Interaction====
-The primary inputs of the piano are the keys and pedals. The keys send discrete signals based on which key is pressed and analog signals based on the relative force with which the key is struck. The pedals send binary signals.
+The primary inputs of the piano are the keys and pedals. The keys send discrete signals based on which key is pressed and analog signals based on the relative force with which the key is struck. The pedals send binary signals. The signal medium is a physical lever.
 The input signal from the keyboard to the action subsystem is in the form of material and energy. Which key is pressed determines which individual pitch section of the action is activated and the energy input to the key determines the output energy. The action sends the signals and energy to the hammers and mutes by striking the hammer and lifting the mute off the string for the note corresponding to that key. Once the key is released, the action subsystem instantly dampens the sound with the mute and allows the hammer to fall back to rest position.
@@ Line 329: / Line 331: @@
 The keyboards and pedals are oriented to allow an ergonomic playing position. The action subsystem is positioned centrally between the keys, hammers, and mutes so that it can receive direct inputs and send outputs to those systems. It is also oriented linearly across all the notes to provide equal signals to all note outputs. The pedal push-rods run up the side of the piano and operate bars across all the notes. That way, they don't interfere with the action subsystem by running up the middle, yet it can still modify signals to all the notes.
 ====Global, Societal, Economic, and Environmental Factors====
+=====Societal====
-	A piano is a mechanical device, with all of the subsystems being interlinked via physical connections.  The keys and action are directly linked through a system of levers and springs, and they send discrete and analog signals in the form of mechanical energy from the user inputs, being the keys and foot pedals, through the action to the hammers and mutes.  The energy is converted from mechanical to acoustic by the strings, and the signals become acoustic signals.  Because of this, the strings and soundboard are the only component which is not physically connected to the action, but the hammers do make physical contact with the strings during operation.  This gap between the mechanical action and acoustic subsystem is necessary for this conversion of energy to take place.
+The compact layout of subsystems allows for a smaller overall footprint of the piano. It can therefore be used in a home or studio where space is limited at the cost of a slightly lower acoustic performance.
-	An upright piano is much more cost effective than a grand piano, in that it is smaller and requires less material to manufacture, with the cost of a lesser acoustic performance.  The inner workings of the action are constructed almost completely from wood, which creates a fairly durable design, but is much less costly than any form of metal or plastic, and generally will result in better acoustic performance.  This economic drive can also relate to environmental reasons, as wood is readily available, and is a renewable resource.  Being constructed of mostly wood, the piano also tends to have an appeasing look in the home as well.
+=====Economic=====
-	The arrangement of the subsystems in an upright piano differs from that of a grand piano, in that they are in a more compact arrangement.  This makes an upright piano much smaller and more household friendly.  The main drawback with this type of arrangement is a slight decrease in acoustic performance.  The action is directly adjacent to the keys because it allows for more responsive input, since the distance between the keys, which act as levers, and the action is smaller, and therefore will respond quicker and most likely have less maintenance issues.  The action must be adjacent to the strings and soundboard in order for the mechanical energy to transfer properly.
+An upright piano is much more cost effective than a grand piano, in that it is smaller and requires less material to manufacture, with the cost of a lesser acoustic performance.  The inner workings of the action are constructed almost completely from wood, which creates a fairly durable design, but is much less costly than any form of metal or plastic. Wood is limited in shape, though. The directional strength with the grain lends itself to linear-shaped components that govern subsystem shape and even product shape.
 == Citations ==
 All knowledge in this section of the report was obtained from our elementary and/or background knowledge of pianos, physics, and this pdf: http://www.ptg.org/userfiles/file/learningCenter/How_A_Piano_Works.pdf

@@ Line 293: / Line 293: @@
 The action as a whole contains the hammers and mutes, but within the action, there is a separate subsystem that takes input from the keys and pedals and operates the hammers and mutes. It consists of a pull-rod connected to the keys, a lever to operate the mute and a push rod that operates the hammer. To the right is an animated gif of the action-hammer-mute subsystem working. The hand is pulling the rod typically attached to the keys(See figure on right.).
 ====Keys====
 The keys are the most easily accessible levers on the piano and serve as the primary input. They have no axle or spring; instead, they rest on a point on the bottom of the key and fall into place by weight balance. They transmit work done by the player's fingers through levers to kinetic energy within each subsystem in the action. This kinetic energy moves mutes and brings the hammers up to a high speed.
 ====Hammers====
 The hammers are felt-covered wood levers that transmit kinetic energy through a physical striking movement into oscillations in the strings. They have light springs to return them to rest position.
 ====Mutes====
 The mutes are felt pads that press against the strings to dampen sound. They are on steel levers and use strong springs. Mutes for the lowest notes have two felt pads that are closely formed to match the thicker strings. The mid-upper notes have flatter pads. The highest notes do not have mutes because their sound dies out quickly without a mute.
@@ Line 304: / Line 302: @@
 The right pedal operates a metal bar that raises all the mutes off the strings simultaneously. A wood lever along the bottom of the piano on a spring operates the push-rod to transmit motion to the metal bar. The metal bar also has a spring to return it to rest position.
 ====Una Corda Pedal====
-The left pedal operates a wood bar behind all the hammers. It moves them closer to the strings so they can't gather as much kinetic energy in their swing. The resulting sound is more quiet. The wood lever across the bottom of the piano is on a spring. The wood bar moves under the influence of gravity.
+The left pedal operates a wood bar behind all the hammers. It physically moves them closer to the strings so they can't gather as much kinetic energy in their swing. The resulting sound is more quiet. The wood lever across the bottom of the piano is on a spring. The wood bar moves under the influence of gravity.
 ====Strings and Cast-Iron Frame====
 The strings and cast-iron frame are on the back of the piano. The strings are meant to resonate at a frequency based on their length and mass. The lower notes are thicker and therefore heavier due to a wrapping of thicker wire around a basic steel wire. The cast iron frame supports the tension in all the strings.

@@ Line 10: / Line 10: @@
 One of our biggest problems is still attendance. Meeting directly after MAE 277 ensures timely meeting attendance, but our main meeting for this gate was on a weekend, and several group members showed up somewhat late or not at all. The absence of the group member during the actual piano dissection has proved very problematic, as they have less insight into the workings of the piano and very little knowledge of the steps we took to dissect it, which impacts their ability to contribute to the write-up of Gate 2. We will continue to stress the importance of attendance. To prevent missed meetings, we will contact group members shortly before meetings to verify their attendance.
+We did avoid the problem of late work, though, by meeting after lectures to monitor progress. Due to scheduling issues, our planned dissection was planed closer to the deadline than desirable. However, the contant progress updates kept the group on track so that only a format check and proofread were needed to finalize the gate before the due date.
 Our other most pressing problem is our inability to effectively work on important sections of the wiki pages simultaneously. We discovered during gate one that there is the possibility of accidentally overwriting work done by other gate members working on the same section if one saves after they do. To date, we have attempted to avoid this by having everyone work on different sections, and also having them prepare their sections in external word processors, but it became somewhat complicated to coordinate and took significantly longer to update key sections of Gate 2. In the future, we will most likely stress the use of word processors instead of the actual wiki pages.