Design Review #2 - Columbia University

ComponentsShadow IncorporatedDesign Review #2A number of components and materials need to be purchased and manufactured in order tosuccessfully construct the catamaran and design a functional sonar system. The necessary raw materialsneeded to construct the boat are Styrofoam, balsawood, fiberglass, polyurethane, and Plexiglas. Thebalsawood strips can be purchased through McMaster-Carr. These strips will be 1/8” x 6” x 36” for acost of $2.98/strip. They will need to be sanded down in order to achieve the appropriate thickness of1/16”. The fiberglass can also be purchased from McMaster-Carr in 1/8” x 12” x 12” sheets, which cost$7.57/sheet. The Plexiglas that will be used for the encasing of the electronics will be purchased fromMcMaster-Carr in sheets of 1/8” x 12” x 12” at a price of $17.61/sheet. It may be possible to find thePlexiglas in the lab and eliminate this cost. The polyurethane used to give the materials a waterprooffinish can be found in the lab thanks to Bob Stark. The Styrofoam required to build the ribbing of theboat is standard packing Styrofoam and was obtained free of charge.Piezoelectric crystals, batteries, a microprocessor, an LM555 timer, a pulse width modulator, opamps,resistors, transistors, capacitors, and a protoboard are all necessary components for creating afunctional sonar detection system. The op-amps, resistors, transistors, capacitors, and protoboard can allbe found free of charge in the Mechatronics Laboratory. The piezoelectric crystal transmitter/receivercan be found on EBay for a price of $8/crystal. Crystals were purchased that function best at a resonantfrequency of 40 kHz. A PIC microprocessor can be acquired from Microchip Technology Inc. Amicroprocessor with 8 ports is easily enough to take all of the inputs from the sensors and motors.Microchip allows their components to be sampled free of charge. The LM555 timer and pulse widthmodulators were obtained as a sample product free of charge from National Semiconductor. Finally, thebattery set up, which may possibly need to produce upwards of 20V, can be purchased from a localautomotive store or perhaps Radio Shack.The components needed to propel the boat are the propellers and DC motors. Two 1.5-3.0 voltDC motors were purchased from Radio Shack for a price of $2.49/motor. In addition to that purchase,Bob Stark donated two larger DC motors, which have a capability of using upwards of 5.0V and rotatingat 12,000 RPM. These donated motors may prove to be too powerful for our system’s needs. The two1” propellers were found at American Hobby for a price of $4.00/propeller. These propellers will easilyproduce enough thrust to overcome any open water currents, as well as maintain the speed of theswimmer.