At the bottom of the page are papers I have written for BU classes.
For my Intro to Design and Manufacture class, I designed a system to lift a load off the ground and transport it over a distance. The system used a hoist, trolley, I-beam, and bolts selected from McMaster-Carr and the system was proven to be safe in terms of buckling and deformation of the parts used.
For my intro to SolidWorks class, Project Development and Design, we were tasked to build a small electric car that would race down a six-foot long track, hit a wall, reverse direction and race backwards. Working with a partner, we designed a wooden base to hold the chassis from a remote controlled car (we were allowed to use store bought chassis, but nothing else), we wired a double pole, double throw switch to the motors and a nine volt battery. I later designed and installed a plunger on the front of the car compressed back with a spring attached to a trigger on the front of the car. When the car hit the wall, the plunger would release and launch forward a couple of inches, flipping the switch to reverse while also giving the car momentum backwards so it could switch directions faster.
For an introduction to engineering class, Project Development and Design, we were asked to make a small electric car that would race down a six foot long track, hit a wall, and race back. Part of our grade was based on how well we did against the other team’s cars. The suggested switching mechanism was a double pole double throw switch that would change the direction of the current through the motor, reversing its direction.
For my team’s design, we decided to use the switch idea but add another aspect to make the car switch directions a little faster. This was to try to minimize the acceleration time when the car switches directions, as that was wasted time. To the front of the car, we added a spring-loaded bumper. When the car hit the wall, the bumper would compress slightly, releasing a hook, allowing the bumper to shoot out a couple of inches, propelling the car backwards. At the same time, the bumper would release the switch, which we also made spring-loaded using a binder clip, reversing the direction. The end result was that while the motor was building up speed and fighting the inertia of the car, the spring would be pushing in that direction, making the process significantly easier. The lowered acceleration time helped us beat other teams with similar maximum car speeds.
For my Engineering Mechanics I class, we had to design and construct a two-dimensional truss out of drinking straws and foam gusset plates. The group was graded on how much the truss held (minimum of 0.4 kg), accuracy of how much the truss could hold, accuracy in which member would buckle first and the load to cost ratio.
In order to help cut the straws so that scissors would not pinch the straws and thereby weaken them, I also designed and built a small hot wire cutter to use.
For my Design and Manufacture class, we were assigned a project where we were to think of a product, design it in SolidWorks, and have it made. My team and I decided on a “Balisong keychain,” based off of the knives. A Balisong knife, or butterfly knife, is essentially a blade attached to two handles that pivot about the base of the blade, as shown in the figure below.
Our idea was to make a similar product but replace the blade of the knife with a slot to put a house key. We wanted the key to be removable and to stay in place without damage. The key we based the designs off of was a standard BU Housing key.
The following is a brief description of the design process. A full report is available here: Balisong Keychain Final Report (Please note that this file may not load correctly on all computers)
We decided to make the handles out of acrylic, as it was strong enough while still being light and easy to manufacture. Since all pieces were to be milled on a CNC milling machine, we wanted to make sure that all parts could be made in one pass and would not have to be flipped over to be milled further. Because of this, each handle was made of three layers, top, middle and bottom. This allowed the handle to be chamfered for comfort as well and have the screws countersunk, while at the same time all plastic parts to be machined out of one layer of plastic in one machining process.
The tang (as shown in the picture), which was to house the key, was to be made in a similar fashion out of two layers of aluminum, which would create a depression in the middle where the key would go. The key would be held in place by a set screw that went through the keychain hole of the key.
For my Introduction to CAD and machine Components class, we were tasked at designing a gearbox to a set of restrictions. The restrictions included a bearing life of the product, a specific gear ratio and others. A full report can be found here: Gearbox Final Report.
My team went with a worm drive approach. Our system had a worm drive driving a worm gear. The worm gear was on the same shaft as a spur gear, which in turn turned the output shaft through a second spur gear. As the basic task was fairly simple, most of the project was in finding the correct tolerances for all the parts and bearings, as well as calculating the bearing life. With the exception of the worm drive, which came with its own system for driving, all gears were restricted to the shaft with splines.
Dynamics Project I: Dash
For my first project for my Dynamics class at BU, we were asked to analyze a dynamic situation (movies were suggested). In the Pixar movie, The Incredible, the character of Dash is able to run at incredible speeds. I decided to analyze his running, taking into account drag from air resistance. The conclusion that I came to was that either Dash weighs on the order of 10,000 lbs or that he launches himself into the air about 45 feet and forward 180 feet in his first step. I also found things like how much power he would consume for running at a constant rate and, assuming he has a normal weight, the energy used in his first step. A full report can be found here: Project 1 – Dash
Energy and Thermodynamics Lab: Generating Electricity at Ocean-Air Interface
For my Energy and Thermodynamics class at BU, we were perform a lab of our own design. My partner and I came up with the idea of using thermocouples and naturally occurring temperature differences to generate renewable power. The main source we thought of using was the ocean. Because of the different specific heats of water and air, the temperature of the water and atmosphere over the course of a day varies. We thought to use this difference to have electricity produced virtually all the time. The other sources we investigated were geysers and hydrothermal vents.
Through analysis of water and air temperatures over the course of a year, we found that a system to produce 120 volts using the ocean would cost about $20,000 and take up almost 23 square feet. For a geyser, it would cost a about $1,500 and for a vent, about $800. For both cases would take up less than two square feet. Given the cost and difficulty with setting up these systems, we determined that the application was not yet viable.
A full report can be found here: Ari Morse – Energy and Thermodynamics Lab Report