Projects

2019

Sit-Ski By Axiomatic Design

• For WPI’s MQP (senior project), I worked with three other team members to redesign a sit-ski from the ground up using the rigorous design theory of Axiomatic Design
  
  
• State of the art technology has stagnated, and still fails to intuitively mimic non-disabled skiing technique

• Used Acclaro DFSS software to visually map and break down customer needs (CNs) into functional requirements (FRs) and finally into individual design parameters (DPs)
  
  
• Independence of components is maximized and complexity is minimized to mitigate unintended outcomes
  
  
• Started from a blank slate and designed each component to directly satisfy the required functions

• After many iterations of axiomatic decomposition and revision, a CAD model was created and iterated a few times
  
  
• The resulting concept uses a combination of linear slides and pin joints to enable four independently controllable axes on each ski, allowing the user to perform better skiing technique

• State of the art sit skis are entirely controlled by shifting the user’s center of gravity despite being strapped into the seat, and demand great abdominal strength that paraplegic athletes may not have
  
  
• One of the most important and often overlooked requirements for completing a carved ski turn is control over fore/aft center of gravity

• The controllable axis on each “leg” are: passive fore/aft translation, active assisted vertical translation, active yaw rotation, and passive roll rotation
  
  
• A nested set of linear slides allow for almost 150 mm of suspension travel, and are damped by a mountain bike air-shock

• Frame is made out of T-slot aluminum to simplify manufacturing and allow for adjustability
  
  
• Four linear roller carriages are used on each linear axis to hold high moment loads, allow for slight misalignment, and allow for moderate environmental conditions yet still have low friction

• Each ski intuitively mimics the position of its correlated joystick
  
  
• Yaw is controlled by a worm-drive stepper motor to prevent back-driving
  
  
• Roll is controlled by bowden cables attached to the joystick with a 2:1 mechanical advantage

• User is able to perform a snowplow (pizza) turn, making turning and stopping easier for beginners

• With so much added control, the user is also finally able to perform better skiing technique

• Large plates were waterjet cut from 6061 aluminum, and all parts were lightweighted with CNC mills
  
  
• Smaller aluminum parts were entirely CNC milled
  
  
• I created all toolpaths and performed all CNC operations

• Toolpaths were programed using Fusion 360
  
  
• A simple example of lightweighting on a 3/8 aluminum waterjet plate is shown

• Auto-probing and toolpath optimization were performed to reduce cycle times
  
  
• A video of me lightweighting a linear rail in a Haas VM2 is shown

• Three back-to-back setups for a roll axle block are shown running in a Haas Super Mini Mill

• Video is warp-stabilized, looks jello-y but better than shaky (should have used a Movi)

• Binding mounts were designed and machined to mimic 330-mm BSL ski boots and clip into my skis

• Each yaw mount required six setups

• The assembled “ankles” are shown

• Assembled sit ski without joysticks is shown leaning to one side

• The sit ski was assembled with 3D printed joysticks

• The team consisted of David Parker, myself, Jeff St. Hilaire, and Jared Grier
  
  
• Our advisor was Christopher Brown

• Our poster for WPI’s MQP presentation day is shown
  
  
• We won first place for Mechanical Engineering
  
  
• Our research paper is viewable at https://digitalcommons.wpi.edu/mqp-all/6836/
  
  
• The device is patent pending

Automated Hydroponics

• Working with a team of WPI students in a potential startup effort to create an automated hydroponic system
  
  
• The current concept is designed to work in a shipping container to be self-contained and portable
  
  
• Use of shipping containers for hydroponics has been explored by others however none are fully automated
  
  
• Render of 1/3 scale prototype shown

• Making the system automated has the potential to reduce plant/vegetable costs to be competetive with supermarket prices, while maintaining local grown quality, year round
  
  
• Hydroponics allow plants to get more consistent nutrients and light, making them grow faster
  
  
• AI will be used to further optimize plant growth

• I am the hardware engineering lead for the team and have designed all concepts shown
  
  
• A stepper-driven, bi-directional, full-extension telescoping end-effector was designed to maximize growing area
  
  
• The gantry system is able to move plant trays from a seeding module, to grow stations, and finally a harvesting module without human intervention

• Entered multiple entrepreneurship competitions and have won intital funding and lab space at Worcester Clean Tech Incubator

• Hardware is designed to scale up to a full-size concept
  
  
• V-slot roller carriages allow for almost unlimited linear travel at a low cost
  
  
• All electronics except power supply are contained within gantry

• Prototype bi-directional slides driven by fixed stepper motors
  
  
• Used drawer slides to save on prototyping costs
  
  
• Project is on-going

2018

Roomba Test Platform

• Advanced Design class gave the task of designing a cleaning module test platform for iRobot (rendered colors based on final 3D printed part colors)

• Cleaning module mounting plate required to be adjustable by 5 degrees in pitch and roll, and adjustable in height by 10 mm with a resolution of 0.2 mm

• Height controlled by topmost black screw and angle controlled by two silver set screws on ends of black arms
  
  
• CoG and total mass adjustable by sliding stacks of washers

• De-coupled height and angle adjustment mechanism inspired by a helicopter swashplate
  
  
• Central ball joint allows angulation, horizontal pin in vertical slot on left prevents yaw rotation

• Height adjustment is the first moving stage from the grounded frame

• Green M8 set screw “shaft” threads through red lock nut
  
  
• Upper bushing adds second support to rigidly keep shaft vertical
  
  
• Shaft collars clamp upper yellow arm perpendicular to shaft and keep lower ball joint in place

• Pitch and roll adjustments make up the second stage of movement

• M4 set screws thread through lock nuts in upper yellow arm
  
  
• Lower linkage rod ends are aligned with axes of rotation to prevent binding
  
  
• Green standoff on left prevents blue plate from yawing (anti-rotation bracket)

• Designed and built in roughly 5 weeks. Test platform uses stock Roomba motors and wheels, and allows for mounting of battery and bottom skin

• Height adjustment screw constrained by locknut in orange part
  
  
• Angle adjustment screws constrained by locknuts in black “L” shaped part
  
  
• Angle adjustment linkages properly constrained by rod-ends and inline ball joints

• Height and angle adjustment tested to well within specified tolerances using a dial indicator
  
  
• Final product exceeded customer expectations

Wearable Biometric Sensor

• Generated three ultra-slim, modular housing design concepts for BraveHeart Wireless (https://www.braveheart.life/)
  
  
• BraveHeart Wireless is a biomedical startup working to create a wireless, wearable life sensor system which far exceeds the capabilities of current market solutions
  
  
• For scale, fabric bandage is under 4.5 in. x 2 in.

• Two layouts using a living-hinge clip for secure connection.
  
  
• Designed around vertical pogo-pin connector in rectangular slot

• One layout using phased magnets for easy alignment and attachment

• Professionally 3D printed concepts to test feasibility of size and function

Electric Skateboard v2

• Custom CNC’d motor mounts using Fusion 360 CAM

• Thicker, clamp-style aluminum motor mounts for easier assembly

• Stiffer, standard-mount longboard deck, higher quality trucks and pneumatic wheels

• Re-used battery and one ESC from v1 skateboard
  
  
• Dual, low-kV sensored motors driving 150mm wheels with GT3 style belts

2017

Electric Skateboard v1

• Created an electric skateboard with the goals of being simple, smooth, and quiet
  
  
• Final product has 23 mph top speed and 10-mile range

• Custom CNC’d motor mount

• Carbon laminated mountain board deck

• Non-standard setup using 125mm pneumatic roller-ski wheels

• 5 Wh Li-ion battery, 3kW motor, belt drive, open source ESC driving with FOC

• RC car remote fit into compact 3D printed case

Smart Snow Probe

• Axiomatic design class gave the task of designing anything that could improve snow sports
  
  
• Conceptualized an electronic snowpack tester that helps winter alpinists better predict and avoid avalanches

• Concept uses ultrasonic sensors to plot out snow density vs. depth, which indicates snow instability
  
  
• Entered idea into WPI competition and won scholarship

2016

Portable Speaker

• Intro to design class gave the task of iterating multiple portable speaker designs in under 7 weeks as a 6-person team using Scrum organization

• Led an inexperienced team to a unique final 3D printed solution that utilizes surface transducing technology to create extremely impressive sound quality

• Insured final product and presentation were outstanding and completed on time
  
  
• Inspired a Bose-sponsored WPI senior project team to use this concept in their design

Lathe Automation

• Kineo Inc, in Colorado Springs, Colorado, is an ultra-high precision engineering and machining prototype firm that serves the silicon wafer manufacturing industry
  
  
• One task at Kineo involved more effectively removing chips during operation on a Fryer lathe

• Different solutions were considered in SolidWorks including pneumatic actuated vacuum nozzles and 3D printed vacuum ducting

2015

Hexacopter + Gimbal v2

• Gimbal redesigned with smaller, parallel tubes, central damper, steel fasteners and adjustable camera mount

• New enlarged gimbal mount with steel cotter pin and electrical slip ring
  
  
• Enclosed receiver for dual operator control, bluetooth for changing gimbal settings
  
  
• External HDMI to AV converter and infrared camera control

• Hexacopter frame design by Jakub Jewula used to save time
  
  
• Retractable landing gear to simplify gimbal mount
  
  
• Custom adjustable brightness lighting

• Rear wiring interface for battery with voltmeter and 12 pin gimbal connector
  
  
• Next steps include redesigning vibration damper and increasing retract reliability

2014

Y6v2 + Gimbal v1

• Redesigned from version 1 with stronger, higher precision structural components
  
  
• Brushless gimbal designed around the Sony NEX-5t (swappable to handheld mount in seconds)

• Basic F.E.A. preformed in Autodesk Inventor as an attempt to optimize placement of weight reduction cutouts

• Frame laser cut by online manufacturer
  
  
• 3D Printed Boom Clips

• Reused wiring harness from version 1

• Improved flight characteristics over v1, but still not quite satisfactory performance
  
  
• Wood plates and nylon bolts still not stiff enough

2013

3D Printer

• DIY 3D printer from SeeMeCNC built to dramatically increase multirotor design possibilities
  
  
• Modified secondary power supply for faster heating and upgraded E3D print head with cooling fan for higher print quality

2012

Y6 v1

• Design goal: Create a portable multirotor capable of carrying a 250 g camcorder on a 2-axis mount
  
  
• Constraints: High school freshman – Low budget and limited access to manufacturing tools
  
  
• Design inspired by the Draganflyer X6

• Folding and crash-absorbing design using pipe clips and sheet metal dampers

• Frame was too flexible, resulting in poor flying characteristics
  
  
• Motors didn’t produce target thrust or flight times despite propeller optimization