Centre for Innovation (CFI)
Indian Institute of Technology Madras
Application for the post of Agriscape Project Member (PDC),
2025-2026
Name: Selvakkumaran S V
Nickname: Selva
Roll.no: ME23B199
CGPA: 7.48
Phone: 6369624319
Smail ID: me23b199@smail.iitm.ac.in
1.Why do you want to work on Agriscape? Tell us why you think
you are a suitable candidate- Justify your answer with your past
experience, strengths, and skillset.
I want to work on Agriscape because I like what Sahaay is
doing under it.I like its motive to help farmers in the rural
parts of India, especially small scale farmers who own small
lands who simply cant afford expensive machinery and tools.
I have worked in Amogh and I was part of the mechanical
team. I have experience designing components like robotic
arm, gripper, outer hulls, Frame of the AUV, etc… and many
more…
I believe this experience would come in handy when
designing stuff in the future.
2. Mention all PoRs/activities you are planning to take next year. Weekly,
how much time do you think you will be able to commit to this PoR? How
much time will you commit to other PoRs and academic commitments?
Next year, my PORs include Amogh, and Institute football team.
I believe I will be able to spend roughly 2 to 3 hours per day for
atleast 4 days a week for SAHAAY excluding the time I would spend
for other PORs.
3. Explain a mechanical design you admire (from a product, machine, or
tool).
What makes it efficient or elegant in your view?
A mechanical design which I admire is the Tesla Valve.
The Tesla valve is a passive, one-way flow control device that uses
geometry alone to achieve directional flow resistance.
It has no moving parts at all and I feel like that makes it an elegant
design from my thinking.
Since it has no moving parts, it is more reliable when working in
harsh enviromments which may have high vibrations.
The vibrations may pose some serious problems if moving parts
are involved.
Also they are easy to manufacture and cheap.
Immune to jamming, rust, and fatigue that affect conventional
check valves.
4.What factors do you think need to be taken into account when designing
mechanical tools for small-scale farmers in India? Answer with respect to
what challenges you think small-scale farmers face.
The small scale farmers often have low budgets and are tight
financially.
They have small holdings of land and largely depend on rainfall for
irrigation.
Many rural areas have problems of irregular power supply and
limited fuel availability.
Thet tend to have limited exposure to modern tools or training in
their use and maintenance.
Also, labor availability is usually not uniform throughout the year
and tends to be already low due to their low budget.
Considering all these factors:
Tools must be low cost to suit the small budgets of farmers.
It should be simple and easy to assemble and use and repair as
many users may have low level or no educational background.
As the electricity supply may be irregular, its best to limit the
need/usage of it by making it solar powered or hand powered or
animal drawn.
It must be able to withstand dust, mud, rain, rough handling, and
minimal maintenance for long periods.
The tools should consist of simple components so that thay can
be repaired with locally available parts and skills, possibly by
village blacksmiths or workshops.
5. A farmer reports that their crop-cutting blade gets jammed frequently.
You're assigned to improve the design. How would you approach this
problem?
I would try to analyze what causes the problem first.
I would look into factors like:
a) Crop type
b) Blade type/material/geometry
c) Usage frequency, etc…
d) I would try to get feedback from the farmer if its happening
more under some specific weather conditions, things like that.
Some of the causes maybe:
a) Poor blade geometry such as wrong angle or tooth profile
b) Insufficient clearance for the cut material to pass through
causing material buildup.
c) Dull or low-quality blades
d) Sticky or fibrous crop material clogging the mechanism
e) Lack of self-cleaning mechanism or ejection path
In order to improve the design, I would do the following:
a) Sharpen edge angle
b) optimize rake angle for crop type
c) Increase clearance(spacing) to allow cut material to pass
through
d) Use wear-resistant materials like high carbon steel.
e) Surface treating the cutting blade with appropriate processes
to increase wear resistant. Eg: Carbide or Ceramic Coatings –
Reduce friction and prevent corrosion
f) Staggering multiple blade arrangements so larger cut
material can be cut down further so chances of clogging due
to large chunks reduces.
6. Why would you use simulations in mechanical structure analysis? What
results would we get at the end of a mechanical simulation? List the major
pros and drawbacks of simulations in popular CAD software like Ansys,
Fusion 360, SolidWorks, SimScale. Which of these software would you
prefer for simulating a Bicycle Pedal? Why?
Simulations allow us to analyse how mechanical structures behave
under various conditions without physically building them first. This
saves time, money, and reduces errors.
From the simulations we can get a get a variety of data like:
a) Stress Analysis
b) Strain and Deformation
c) Fatigue and Failure Prediction
d) Thermal Effects
e) Vibration and Modal Analysis
f) Safety Factor Estimation
For general design cases, all 4 of them are quite accurate and
suitable.
But for industry grade cases, Ansys is preferred as its highy accurate
and has many more simulations library that the rest,
When it comes to speed, all of them are reasonably fast except
Ansys which takes relatively longer time, but highly detailed results.
When it comes to the ease of use, Ansys has a tough learning curve,
whereas the rest are quite easy to learn and use.
Also, its more expensive that the rest as well, whereas fusion and
solidworks are affordable mid-range choices.
Simscale is fully cloud-based and the price is also subscription/
cloud based model.
For high end simulations, R&D, high precision, critical systems,
Ansys is the best as it is highly detailed and despite taking longer
time.
For general product designing, Autofusion and Solidworks do well
enough.
For collaborative designing based on cloud, Simscale is more
comfortable.
7. Pliers are one of the most commonly used hand tools in mechanical and
electrical work. Draw and label the different parts of pliers. Describe how
the position of the pivot affects the mechanical advantage of pliers.
For a force of F (Newton) squeeze on the handles of the pliers, determine
the force K applied to the round rod by each jaw. In addition, calculate the
force supported by the pin at A.
The pivot position determines the ratio of the Force delivered at the
jaws to the Force applied at the handles.
The greater the distance from handles to pivot and lower the
distance from the jaw to the pivot, the greater the mechanical
advantage.
8. The projections of a 3-D object is the basic step in designing things.
Project the 3-D model given in all three planes (front view, top view, side
view), preferably in AutoCad (Fusion360 works as well). (The cuboidal
button has a length and width of 10 mm. The cylinder in front is centered
across the camera's face.)
Use the bottom link
https://drive.google.com/file/d/
1rA9hQKKvqWOy2qSn1xPKxx8eCIMK29mu/view?usp=sharing
9. The discovery of gears has made human life much simpler and easier
than before. Gears are everywhere around us, and are super important in
mechanical design
a. What is a compound gear train? How does it differ from a
simple gear train?
In a simple gear train, only one gear is mounted per shaft.
In a compound gear train, more that 1 gear is mounted per shaft.
The gears on the same shaft are fixed together, so they rotate as a
single unit.
A simple gear train is straightforward but limited in the gear ratio it
can achieve.
A compound gear train offers more flexibility and power
transmission in a smaller space by combining multiple gears on the
same shaft.
SIMPLE GEAR
TRAIN
COMPOUND GEAR
TRAIN
b.You’re biking uphill and switch to a lower gear. Why does pedaling become
easier but slower?
When we lower the gear, the front gear shifts to a smaller
gear and the back gear shifts to a larger gear.
The front gear becoming smaller affects the motion such
that for one full pedal the distance traversed by any point
on the chain is decreased than before. Thus the forward
distance traversed by the cycle per pedal decreases, so we
go slower.
The back gear becoming bigger affects the motion such that
the amount of rotation of the pedal per rotation of the back
wheel increases than before. Thus, for a given no. of
pedalling, the forward distance covered by the cycle
decreases, thus speed decreases.
This is essentially a trade off between the power and the
speed of the cycle.
That is the why the speed decreases while it becomes
easier to pedal.
c.If the input speed given to the driver gear is N1, find the output speed N6 and
the Gear ratio. Assume that speed of gear 2 = N2, gear 3 = N6 and so on. Similarly,
the number of teeth on the driver gear is T1, gear 2 is T2 and so on.
d. What is a synchronous belt? Distinguish the Vee belt from the
synchronous belt.
A synchronous belt is a toothed belt.
The tooth mesh with matching toothed pulleys.
This belt maintains a constant speed ratio.
It should be aligned precisely for operation.
There is no slippage using it, therefore its highly efficient and is
ideal for applications requiring precise timing (like engines or
automation systems).
Used where accurate speed and positioning are critical like timing
systems, robotics, and camshafts.
VEE BELT:
Has a V shaped profile.
It has no teeth for engaging with the pulleys. Rather the
engagement is due to friction.
Since it relies only on friction, slippage may occur. Hence, not as
efficient as synchronous belts.
Since, slippage is allowed, its not as sensitive to alignment.
Suitable for applications where the timing or accuracy is not as
crucial.
Fans, pumps, conveyors (non-critical timing).
There are some Vee belts with V-shaped cross-section with notches
or cogs on the inner side, but they are not the same as
synchronous belts because the engagement with the pulley is not
due to the teeth, but due to friction only.
The teeth are not for timing, but to improve flexibility and heat
dissipation.
10. Design the model from the videos given in Fusion 360. Upload the
model in f3d format to a GDrive folder, and share the link here. Remember
to make it public for SMail users.
Use the below link:
https://drive.google.com/file/d/1EHEWrqwaU57xomX8cMGIS5DTNdJgxlzM/
view?usp=sharing
11. With respect to load bearing- If a wheelchair frame is made from an
aluminum alloy with a yield strength of 250 MPa, and a 1.5-meter tube
with a cross-sectional area of 400 mm² supports a 100 kg user, calculate
the stress on the tube. Is the material selection appropriate based on this
calculation?
The stress on the tube is only ~2.45 MPa, which is much lower than
the yield strength (250 MPa).
Yes, the material (aluminium alloy) is more than adequate for
supporting a 100 kg user — safe with a very high margin.
Even considering dynamic loads or safety factors, the design is
structurally sound under axial loading.
Bonuses:
1. Imagine you need to create a desk organizer that holds pens, sticky
notes, and a phone. What design features would you include to
maximize space and user convenience? Put all your thoughts
together and build a model in Fusion 360. Upload the model in f3d
format to a GDrive folder, and share it with all SMail users. Also
share a drawing of what you planned and what you wanted to
include in the desk organizer.
The below is the design I came up with.
Since I wanted to maximize the space available, I made foldable
boards on which we can stick the sticky notes.
That way its more compact and we need to open it only when we
want to view the notes.
Also I made spaces in the front of the phone compartment, so
the user can see notifications and the time without having to lift
the phone out.
USE THE BELOW LINK:
https://drive.google.com/file/d/1Cm-U8xlEfITuPfZbkHRKep4Nm_gHQxcm/
view?usp=sharing
2. As a continuation to Q8 do this as well.
Motion simulation - Engine Design in Fusion 360 || PART II || Beginner's
Tutorial || POWER STROKE
Learn about rendering and appearances and upload rendered pics in drive
as well.(Be very creative about material selection for the rendering - here
physics does not matter, looks does. Can make in glass also XD)
USE THE BELOW LINK:
https://drive.google.com/file/d/
1zEklbHSl2xYyADlrkS9GeMnqOx7k2BgG/view?usp=sharing
3.Wheels are going to be an important part of Agriscape’s prototypes as
they help navigate through various types of fields. List the different
wheels that can be used to navigate in different terrains. For Agriscape’s
seeder model choose the best kind of wheel, and explain what you
considered in your choice.
Solid Rubber
Wheels
Flat, hard terrain (concrete,
pavement)
Durable, puncture-proof, low
traction
Pneumatic (Air-Filled)
Tires
Uneven, soft, or agricultural
fields
High shock absorption, good
traction
Cleated or Lugged
Agricultural Tires
Soft soil, mud, loose
sand
Deep treads grip well in soil, prevent
slippage
Caster
Wheels
Indoor, flat surfaces (for
steering)
Low traction, highly maneuverable
Omni/ Mecanum
Wheels
Robotics indoors, smooth
terrain
Great for lateral movement, poor off-road
performance
Spiked or Studded Wheels
Snow, icy or very soft
terrain
Grip into the surface, but can damage soil
or roots
Personally , I believe lugged pneumatic tyres are the best.
Its deep treads gives a lot of traction and prevents slippage over
a range of surfaces.
The seeder will likely operate on tilled soil, soft dirt, or slightly
muddy ground.
Such surfaces require traction to avoid sinking and slipping.
Pneumatic wheels being air filled absorb shocks due bumps and
reduce impact on the operator's arms(assuming manually
driven).
