Construction

CAD Drawings

Annotated Part Drawing 1

Mock Up

Testable Parameters (Physical Model)

Three of the most important parameters that we tested with the physical model are size, durability, and cost.

Durability: Our main concerns from durability stemmed from needing to move the model to the two showcases, especially the Boston one, because we knew we'd have to take it on the bus. We also needed the structure to stay very stable, as the lasers had to be fine-tuned to precise angles, and we couldn't have them moving when we didn't want them too.

Cost: A major constraint on our physical model was our $100 budget, which severely limited what we could build. We primarily used VEX parts to construct the physical model, in addition circuitry and laser diodes we found in the classroom. Our main expense was buying 6 beam splitters for $60. We also bought lasers for $22 that we didn't end up using, and $7 for mirrors that we needed to reflect the lasers.

Size: Size was an interesting challenge for us, because we wanted it to be as big as possible, while still being able to carry and transport. We wanted to make sure that we had plenty of space for all the laser diodes and beam splitter systems, but we also couldn't make it too big, as it would have required more materials and time to build the framework.

Finale Build Procedures Overview

The first step to our building plan was to construct the base and framework that we could attach everything to.
Design and build the individual diode/beam splitter modules out of the gears, cut metal pieces, and motors.
Attach the modules to the top of the framework.
Attach the mirrors and optical sensors so that they're aligned with the lasers.
Attach motors, battery, and do cable management.

Resource Planning

Pricing Spreadsheet

Build Modifications

Altitude: With our original design, we were unable find the altitude of the plane, one of the criteria. To solve this problem, we added the cone system. By comparing the results of the cone system to that of the cylindrical system, we could find the altitude.

Circuitry: We were originally going to use stand alone lasers. However, the battery life was a major concern. In switching to wired laser diodes, we had to learn how to build the circuit such that each laser got the correct current and voltage without burning out.

Laser requirements: We originally planned to use a Geostationary Satellite. However, as they are significantly farther from Earth, the laser we would have needed was unrealistic. We then switched to a Low Earth Orbit satellite, which produced realistic laser calculations.

Construction Process

We started by constructing the base and attaching the Vex optical sensors. We attached them to be in a circle evenly spaced out.

We reinforced the beams to reduce movement, and by extension error, as much as possible. We also added top beams to later add the lasers.

We used these to stack the lasers and beamsplitters to get both the cone and cylinder. They were then attached in the center of the top.

Here was our circuit for the laser diodes. All the laser diodes were in parallel with each other and in series with a 16 ohm resistor. They were given 4.5 V.

Here is the final constructed physical model. The stacked lasers and gears were attached in the center using a motor in order to keep them stationary, while still giving us some room to adjust them. Mirrors were also added along the perimeter of the structure in order to reflect the lasers into the correct paths and ending at the optical sensor. The breadboard for the circuits were attached to the top and we replaced the alligator clips with better wires, and attached them to the laser diodes using electrical tape.

Page updated

Report abuse