I am a graduate student at Purdue university. This is a documentation of some of my projects. Hope you enjoy reading it.
Want to know more about my projects or interested in working together, feel free to get in touch on: dvagholk@purdue.edu
Call for Papers - African Journal of Biological Sciences, E-ISSN: 2663-2187, ...
Portfolio
1. devashri
vagholkar
portfolio
I am a maker. I love to make things- physical, digital and edible.
With 4 years of industry experience across core mechanical engineering
and product design, I am now exploring the computational side of product
design as I pursue a Masters degree from Purdue University. My research
interests lie in digital-physical systems. I am currently exploring the
computational side of product design.
In my free time I am polishing my Japanese skills or trying a new recipe.
This portfolio is a documentation of my select academic and personal
projects to showcase the breadth and depth of my skills.
2. chalopede
chalopede
what?
Bachelor’s thesis project: Design and
Prototyping of Multilegged Walking
Mechanism
where?
Homi Bhabha Centre for Science Education,
Tata Institute of Fundamental Research
when?
Aug ‘14 – May ’15
who?
A team of three girls.
Collectively worked on every aspect of the
project from initial mechanism selection to
final prototyping and testing.
robotics|walking mechanism|CAD|electronics|arduino|rapid prorotyping
Chalopede is a six-legged walking robot developed by our team as a part of our
bachelors thesis project in mechanical engineering. The aim of the project was to
design and build a walking mechanism for uneven terrain. Such mechanisms would be
further developed for applications in planetary surveillance, internal inspection of
machines, surveillance of calamity struck areas etc. After weighing various parameters
a six-legged mechanism that follows an alternating tripod gait inspired by the
arthropods was selected. Following an iterative design process a fully functional
prototype was successfully developed.
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3. chalopede
chalopede 2
Parameters Theo Jansen Klann Linkage Biped Quadruped Hexapod 8 legged
Ability to walk on uneven surface (50) 2 2 5 4 5 5
Resources (40) 4 3 4 4 5 3
Stability (40) 3 3 2 3 4 5
Control (30) 4 4 2 2 3 2
Cost (30) 4 4 1 2 2 1
Maneuverability (20) 2 2 5 3 4 4
Weight (30) 4 4 1 3 4 3
Simplicity of mechanism (20) 4 4 2 3 4 3
Manufacturability (30) 4 4 2 3 3 3
Total 980 940 810 900 1130 980
Selecting a mechanism was the first and most
critical decision of the project. The team started
with a literature review followed by a
quantitative analysis to compare the mechanism
based on a list of parameters. A hexapod
mechanism was selected for further detailed
design and testing.
Selection of Mechanism
5. chalopede
chalopede
Our team performed direct and inverse
kinematics to determine optimum length
of each link and rotation angles of each
joint. This was followed by CAD modelling
of a stick model to simulate and verify the
stride and step height.
Mechanism
Synthesis
1
CAD
modelling
2
Coxa
Femur
Tibia
Leg Anatomy
Stick model
4
6. chalopede
chalopede
An electronics system was designed to
power and control 18 servo motors (3 on
each of six legs). It was then tested for
power and load requirements.
Open source Arduino platform was used to
program the alternate walking tripod gait
as observed in the cockroaches.
Electronics
& coding
3
Servo controller
board
DC-DC
converter
Battery
+
+
GND
GND
+ GND
TX RX
Coxa
Femur
Tibia
Coxa
Femur
Tibia
Coxa
Femur
Tibia
Arduino
RX TX GND
Coxa
Femur
Tibia
Coxa
Femur
Tibia
Coxa
Femur
Tibia
5
8. chalopede
chalopede
•Sturdy
•Stands stable on 6 legs
•Servo bracket broke while testing
•Chassis over designed
Prototype
Testing
5
•Longer Tibia
•Lighter chassis
•Highly unstable due to flexing of
Tibia
•Cannot stand on 6 legs
•Unable to walk due to excessive
flexing
•Sturdy
•Longer tibia like proto 2 but form
like proto 1
•Stronger Aluminium servo brackets
•Stands stable on 6 legs
•Successfully walked on uneven
terrain
7
9. auro
auro
what?
Asylum Hack an elderly care hackathon
organized by Godrej Appliances
where?
Maker’s Asylum, Mumbai
when?
Dec ’15
who?
An interdisciplinary team of 6, comprising of
mechanical, electronics and computer
engineers. In addition to ideation and design
research, I was responsible for prototyping
and design of the hardware.
design thinking|internet of things|arduino|rapid prorotyping|elderly care|problem solving
The aim of the hackathon was to prototype and demonstrate an IoT based solution
towards elderly care. Our team developed smart spectacles that can assist the elderly
people who stay alone away form their family.
The team brainstormed on the problems faced by the users i.e. the elderly, based on
interviews and personal experiences with the elderly. Various user tendencies such as
forgetfulness and hesitation towards technology were identified. Following a design
thinking approach and using open source IoT platform these problems were addressed
in our technological solution. After presenting our prototype to a panel of judges from
Godrej Appliances, our team won the first prize along with a cash prize of INR 50,000.
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10. auro
auro
Target users:
Elderly people staying alone
Identified problem/situation:
No family member around.
Nobody to look after. Lack of
care and attention.
Selected design statement:
Design a companion/assistant
to take care of the elderly
people staying alone
User research1
9
11. auro
auro
Design requirements/constraints:
Functional:
• Should assist the elderly in his day-to-day life
• Should track the wellbeing of the user
• Should keep the family members informed
about the user’s condition
User-centric:
• Should be acceptable by target group
• Should not be an annoying and difficult to
handle technological device
• Should not require frequent maintenance
Product attributes:
Functional:
• Audio assistant to remind about daily tasks-
wake up alarm, medicines, etc.
• Accelerometer- to detect sudden fall of the
user
• Heart rate sensor- to track pulse rate
• Cloud access- to store data and allow family
members/ doctors to access it
• Text message- send text message to family
members in case of emergency
User-centric:
• Feature added to the spectacles as most
elderly people use them. No additional
wearable
• Over night charging when the spectacles are
taken off
Ideation2
10
12. auro
auro
Mapping the process helped in determining the components
and their connecting links to design the electronic circuit and
the program.
11
13. auro
auro
A working prototype was developed using MediaTek LinkIt One
prototyping board.
Considering the bulky electronics a casing was designed to be
mounted on the spectacles.
Casing parts were assembled from laser cut MDF sheet.
Further scope
Reduce the size of electronic components.
Make the assistant a modular integrated part of the spectacles
Work on the form of the casing
Further develop the design for mass manufacturability
Development3
12
14. sleek
sleek
what?
Design challenge as a part of recruitment
process of a design company
where?
Personal project
when?
June ‘18
who?
Design engineer
jewellery design|mechanism|CAD|design for manufacturability|color material finish
The challenge involved designing a bracelet based on the given rendered image. The
given image was to be converted into a fully functional and ready to manufacture
product. Based on the given constraints a locking mechanism had to be designed
followed by selecting material and manufacturing processes for each component.
13
15. sleek
The challenge:
Identify the detailed steps
involved in making a bracelet from
designing to mass manufacturing
Material:
•Water resistant
•Aesthetic
•Withstand -10 to 65°C
Usage:
•3 year warranty
•Twice daily use cycle
Manufacturing:
•Tolerance 30μm (critical)
80μm(non-critical)
•500k units monthly
•Surface finish and optimum
quality
Design requirements:
Elegant
Intuitive
Modern
sleek
Design
Simple
Minimal
Sleek
CMF
Silver
Matt and gloss
combination
Interaction
Easy to use
Adaptable
The approach:
The process began with identifying the
characteristics of the product personality
followed by designing and engineering the
product around these characteristics.
14
16. sleek
sleek
Engineering1
Lock pin
TPU rubber cover
Nylon washer
Main housing
Dial
Chain connector
A locking mechanism was designed
followed by CAD modeling of every
component.
15
17. Alignment protrusion acts like locator
and aids workers in assembly
sleek
sleek
Connector pin extends in the main
housing preventing the dial from
opening up.
Dial rotation restriction acts like an
intuitive feedback and the user is
assured that the bracelet is locked.
Slot opening in the dial allows only
one open position to pull out lock pin
Rubber cover hides the
connector pin along with
providing flexibility to
fasten the connector to the
main housing
16
18. sleek
sleek
Manufacturing2 Component wise material and processes
were selected for mass manufacturing and
tolerances
Aluminium
Die casting followed by
machining of critical
faces
Aluminium
Die casting followed by
machining of critical faces
Nylon
Bought out standard
component/ Injection molded
TPU rubber
Injection molded
SS with silver finish
CNC machining
Silver
Bought out chain
SS with silver finish
CNC machining
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19. udaan
18udaan
what?
American Institute of Aeronautics and
Astronautics (AIAA) Design/Build/Fly,
international aero modeling competition
where?
Cessna Airfield, Wichita, KS, USA
when?
Aug ‘13 – Apr ’14
who?
A part of a team of 7. My role mainly
involved performing stability analysis and act
like a connecting link between the
aerodynamics and structures sub-teams.
Being a small team we all were a part of the
manufacturing process.
aeromodeling|engineering|prototyping
Udaan (flight in hindi) was our team’s model for the AIAA Student Design/Build/Fly
international aero modelling competition. The competition challenged undergraduate
students to develop an aircraft that can make the highest score during the fly-off. The
task involved optimizing the speed, weight and size of the aircraft. Constrained with
the current draw and to accommodate and lift the specified payloads, we had to
balance between propulsion, aerodynamics and structural sub systems.
After testing 2 prototypes, our final model ranked 48th internationally at the fly-off in
Wichita.
20. udaan
Design Process1 Starting with Score analysis we could
determine the critical factors and their
relationship with design parameters. The
identified parameters were used to
perform a Figure of Merit Analysis to
determine the best aircraft configuration.
After selecting the conventional
configuration an iterative design process as
shown in the chart alongside was followed
until all the conditions were satisfied.
My role
No
No
No
Understand Problem Statement
Score Analysis
Estimate Weight
Select Aerofoil
Determine Wing Planform
Tail Design
Fuselage Design
Dynamic and Static Stability
Thrust Selection
Motor and Battery
Test for static thrust
Performance Test
Final Model
Important Parameters
Wing
Loading &
Constraint
Model
Takeoff
distance and
Flight Time
Thrust/ Weight
ratio
Parameter Weight Conventional Flying wing Twin boom Biplane
Weight 35 1 1 0 -1
L/D 30 1 1 0 -1
Drag 20 0 0 -1 -1
Stability 10 1 -1 0 0
Manufacturability 5 1 -1 0 0
Total 100 80 50 -20 -85
19udaan
21. udaan
Designing2 My role in stability
analysis involved
empennage and
aileron sizing and
checking the
moments for static
and in-flight stability
of the aircraft.
Manufacturing3 Prototypes were developed mainly using balsa wood
and balsa ply. Critical components such as airfoils were
laser cut and some components we hand fabricated.
Carbon fiber tubes were used in strengthening the
wing. Nose was mad from foam to give it the desired
aerodynamic shape without adding much weight.
20udaan
Aerodynamics
Structures
Stability & Controls
22. udaan
Testing4 First prototype was tested to check
different battery packs with the flight
performance.
21udaan
Second prototype was designed after
considering all the constraints mentioned
in the problem statement. The structure
turned out to be over designed and
heavier than expected.
Third prototype accounted for the failings
of the previous one, was lighter and
smaller.
23. brix
brix
what?
Personal project on exploring modular design
through rapid prototyping
where?
Maker’s Asylum a community makerspace
when?
Jun ’15
who?
Intern
modular design|design exploration|rapid prorotyping|origami
As a part of my internship at a makerspace- Maker’s Asylum I took up a personal
project on modular design. The aim of the project was to understand modularity in
design through ideation and rapid prototypes. I tried to come up with different ideas
where modular components can be used. Some ideas were selected for prototyping
using different materials. By the end of the project I was able to recognize the
properties of modular designs and create different forms using different materials.
22
24. brix
brix
Laptop stand1 A laptop stand made from 3mm laser cut corrugated plastic sheet.
23
Internal rib structure allows to support load upto 3 kg.
Only 3 different components
Joined by notches and no
permanent joints allows for easy
replacement of components
26. brix
brix
Modular origami3 Exploration of modular
origami using train tickets
to make small mood
lamps
25
Conclusion4 In the big picture, modular designs are
adaptive, easy to manufacture and
maintain and sustainable
27. STEM
stem
what?
Personal project as a volunteer of STEM
educator
where?
Dharavi Diary- Slum Innovation Project
when?
May ‘16- Dec ‘17
who?
STEM educator
social responsibility|community|hands-on learning|STEM
As an effort to develop and execute hands-on learning modules I volunteered as a
STEM educator for the Slum Innovation Project. The experience allowed me to
train/mentor children on various STEM topics using hands-on project based learning.
The projects were not limited to school textbooks but stressed on developing life skills
such as creative thinking, problem solving, leadership, entrepreneurship.
Leveraging my engineering and design skills I developed modules on different topics.
These modules had a physical form to be more engaging and enhancing the retention
of concepts.
26
29. STEM
Frugal innovation4
Mentored a team of kids towards interaction
design of a 6’x6’ e-waste art installation. The
interaction used IR sensors to detect hand gestures
that activated LEDs to highlight global issues.
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A solar grill built as an outcome of a STEM
workshop on ‘Ray diagram’.
stem
30. plotbot
plotbot
what?
Personal project
where?
Rapid Solids Pvt. Ltd.
when?
Dec ‘17
who?
Engineer
Arduino|CNC|upcycle|mechanisms
A weekend project on making a CNC plotter using junk CD drives.
The stepper motor and lead screw mechanisms were salvaged from old CD drives.
Using an additional servo motor a fully functional mini CNC plotter was built.
Open source code from arduino, processing and inkscape was used to read data from
the computer and scribe it using the plotter.
29
31. hatch door
hatch door
what?
Commercial project on product development
for a mechanical hatch door
where?
Rapid Solids Pvt. Ltd.
when?
Apr ‘18- Jun ‘18
who?
Working as a design engineer I was assigned
this project single handedly
product development|mechanism|CAD|design for manufacturability|rapid prorotyping
The brief was to design and manufacture a mechanically operated hatch door that shall
open and close only once. Additionally the system had to be easily manufactured using
standard components and CNC machined custom parts. Considering the size and
loading of the door a sturdy and smooth mechanical system was designed using
hinges, crank, spring, and ratchet. Component and system level optimization was
carried out to ensure ease of assembly and manufacturability. A working prototype
build from CNC milled parts was successfully tested and delivered to the client.
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