Engineering Trade Studies

Mini-Mozarts performed these engineering feasibility/trade studies as a method to determine feasible design solutions. These studies supplied the necessary information and analysis to make educated decisions about the design.

Key-Linkages - Gordon Farmer

Gordon's trade study determines the optimum dimensions of the four-bar linkage connecting the key of the keyboard and the hammer that strikes the xylophone. His trade study is intended to find the optimum dimension corresponding to the geometry in which the ratio of the speed of the hammer to the speed of the key is the highest. This will allow the product to be used by a wide range of 4 - 6 year old children and not just the strongest among them. The analysis is accomplished through the Vector Loop Method for Kinematic Analysis, Velocity Analysis via Instant Centers, and knowledge of Dead Positions.

• Supplemental Material:
  • Analysis (Matlab file)
  • Tool (Matlab file)
  • Trade Study Tool Verifications
    • Instant Center Analysis
    • Tool Output

Potentiometers - Mike Johnson

Mike's trade study examines different types of devices for using variable resistors to determine the position of a note on the scale. He analyzes three types of devices in the study: linear motion potentiometers, rotary potentiometers attached to a pinion-rack system, and rotary potentiometer connected to a pulley-belt system. The goal is to find the most effective device to connect the note to a variable resistor. The results of this study determine which type of device will be used.

• Supplemental Material:
  • Appendix

Pinned Key-Spring System - Eric Laumann

Eric's trady study analyzes the pinned key–spring system for the product and figures out how to design the spring so it produces the desired result. It is desired that upon the key being depressed, the spring return the key to its horizontal position with the smallest spring constant possible. A small spring constant is desired so that the majority of the input force from the user is transferred to an attached four-bar linkage and not converted into the potential energy of the spring. Eric's trade study gives the group the specifications for a suitable spring to be used in the product.

Control Logic Theory - Bryan Marek

Bryan's trade study developes a self-correcting method on the keyboard in which the user would not be able to advance through a song merely by pressing keys one at a time until the correct one was triggered. A series of multiplexers, decoders, and digital logic gates utilizing Boolean logic are implemented, receiving signals both from the microcontroller and the user in order to determine if the active key was pressed. Bryan's study provides the electronic logic for the group's product.

Xylophone Bars - Phil Moss

Phil's trade study determines the material and length of the xylophone bars to be used in the interactive xylophonic keyboard to produce specific frequencies corresponding to certain musical notes. Secondly, his study determines where on the bars to position the supports. Additionally, his study allows for the integration of a xylophone in the group's product.