Leia Hannes Engineering Portfolio

Product Teardown: SKIL Cordless Screwdriver

Tufts University, Spring 2024: Engineering Design

Project Highlights:

- Used Solidworks to create a 3D model of a SKIL
cordless screwdriver
- Conducted a task analysis and made a decomposition
table for the full screwdriver
- Worked in a team to create a full CAD model and
assembly

This was a team project in which we recreated an electric screwdriver in CAD using Solidworks. We conducted a task analysis on how the screwdriver was used, and then deconstructed it (pictured below). We then made CAD files for each part, and put them together in an assembly (exploded view above). I worked with the team on the task analysis and decomposition table, and individually created the CAD for the casing and the assembly.

Presentation:

Laser-cut Dragon

Tufts University, Fall 2022: Introduction to Engineering

Project Highlights:

- Used Onshape to design parts to
be laser cut to make a dragon
with moving legs
- Coded a makerpi with
micropython to move the legs
depending on whether a light
sensor on top of the dragon was
exposed

For the midterm for my introductory engineering class, we were instructed to make an animal that could move. I decided to make a dragon that could move its legs as though it was walking. I used Onshape to design all of the parts to be laser-cut, and screws as the axles for the gears. The makerpi is connected to a dc motor in the center of the dragon, which spins the central gears. The code for this project makes the motor start and stop depending on whether the rider is sitting on top of it.

Printed Circuit Boards

Tufts University, Fall 2024: Electronics and Controls I

Project Highlights:

- Designed and ordered a printed circuit board (PCB) to take in 12V and offer a 3.3V, 5V, and 12V output stabilized with capacitors (top left)
- Designed and ordered an H-bridge motor driver PCB with thickened copper traces to better handle temperature variation (top right)

For this project, I used KiCad to design PCBs which I then ordered and soldered components onto. The schematics for the voltage regulators (left) and the H-Bridge (right) are pictured below. To the right is the breadboard prototype for the H-Bridge, which has input pins that are connected to a KB2040 to control the direction of the motor.

Soldered PBCs:

Simple Electronic Game

Tufts University, Fall 2024: Electronics and Controls I

Project Highlights:

- Designed and ordered a printed circuit board (PCB) to take in 12V and offer a 3.3V, 5V, and 12V output stabilized with capacitors (top left)
- Designed and ordered an H-bridge motor driver PCB with thickened copper traces to better handle temperature variation (top right)

Robotic Car

Tufts University, Fall 2024: Electronics and Controls I

Project Highlights:

- In the first stage of a two stage project, worked with a team of 3 to design a robotic car controlled by GET requests sent to a raspberry pi that could drive up a ramp.
- In the second stage of the project, redesigned the car to drive up the ramp autonomously and work with another team's car to push a large cylinder up the ramp.

For this project, we were required to create a robot that could drive up a ramp. We then modified it to communicate with a seperate robot on another ramp so the two could work together to push a large cardboard pole up the two ramps.
The original robot (pictured above) has a relatively simple design. The two front wheels (3D printed with TPU) and connected to two DC motors, which are controlled by a raspberry pi sending signals through a motor driver. The back wheels (PLA) are set on a dowel and can spin freely. The robot was initially controlled theough a simple website with some Javascript code I wrote to send GET requests to the Pi, which was running Flask. The robot was controlled through the WASD keys on a keyboard for movement forwards, left, backwards, and right. The video below shows our first trip up the ramp. We ended up driving in reverse up the ramp since it was easier for the car to move that way.

The second stage of the project required some major adjustments to our original design. We were required to communicate with a second robot on a seperate ramp while pushing a tube. First, we needed to be able to go up the ramp autonomously. We achieved this by moving our green wheels much farther apart so they could act as a barrier on the side of the ramp and adding a small caster wheel under the front section (front view pictured left).

The second challenge we faced was creating a sensor so we would know if the two robots were aligned. We made a plow-like attachment for the front of the robot that consisted of two boards wrapped with aluminum foil. The front board was connected to 3.3V, and the back board had 6 distinct strips wired to the rapsberry pi. The video to the right shows our first prototype connected to a series of LEDs.

Finally, we updated our code to change our own speed, listen to requests from our partner robot to change speeds, and to send requests to our partner based on the feedback we recieved from our sensors. The final video below shows our robot (near ramp) working with another robot.

Other CAD Highlights

Tufts University & Personal Projects, 2020 to Present

Project Highlights:

This contains a selection of parts and assemblies I've deisgned using various different CAD software. All of the pictures below are of things that I have designed fully from scratch, mostly to be 3D printed or laser cut.

Pirate Ship, designed in Onshape for lasercutting. Utilized living hinges for the curve of the ship. (Tufts, Fall 2022)

Hair dryer, designed in SOLIDWORKS (Tufts, Spring 2024)

Pulley, designed in Onshape (Tufts, Fall 2022)

Mandalorian helmets, designed in TinkedCAD (Personal Project, 2021)

Captain America's Shield, designed in TinkerCAD (Personal Project, 2022)

Toy Car, desgined for laser cutter (Tufts, Fall 2022)

Tardis, designed in Onshape (Personal Project, 2023)

Merry-go-round, designed in Onshape (Personal Project, 2024)