PEDAL DESIGN REPORT
DESIGN GOALS
Our design goal for our current season was to ensure the accuracy
of all the components. To reduce the cost of production and
machining time. More importantly to overcome the drawbacks of
last year’s design. We also kept in mind the weight of the pedal and
made attempts for weight reduction.
THINGS WE KEPT IN MIND BEFORE
DESIGNING OUR PEDAL
- Should withstand a force of 1500N.
- Throttle cable connection.
A 6mm diameter at 50mm from top.
- Pedal box dimensions.
The pedal must fit in the pedal box so it is important to know
dimensions of pedal box.
- Dimension of pedal.
Length of the pedal should be average foot size of an Indian
men.
MATERIAL SELECTION
MILD STEEL
ALUMINIUM
STAINLESS STEEL
TENSILE STRENGHT
420 MPa
276 MPa
505 MPa
YIELD STRENGHT
240 MPa
145 MPa
215 MPa
DENSITY
7.8 gcm-3
2.81gcm-3
8 gcm-3
HARDNESSS
110 HRB
60 HRB
70 HRB
COST PER KG
40/-
260/-
180/-
WELDABLE
Less than ss
Less than both
More than others
CORROSION
RESISTANT
POOR
LESS THAN SS
VERY HIGH
MALIABLE
MORE
LESS
MORE
-After considering all the above aspects, we decided to choose
stainless steel as our material to make pedal.
-The key consideration were cost and strength of the material.
-Why SS over Aluminium?
Although aluminium is lighter than SS, the yield and tensile
strength of SS is more so a smaller amount of SS can gives us a
strength equivalent to a heavier/larger amount of aluminium. So
this in a way does help us in weight reduction.
-Composition of 304 SS
Chromium 18% - is added to steel to increase resistance to
oxidation.
Nickel 8% - is responsible for a great toughness (impact
strength) and high strength at both high and low temperatures.
Nickel also greatly improves resistance to oxidation and corrosion.
Carbon 0.08% - is present in all steels and is the principal
hardening element. It raises tensile strength, hardness, resistance
to wear and abrasion.
Manganese 2% - strength and hardness; decreases ductility and
weldability; effects hardenability of steel.
Sulphur 0.03% - decreases ductility and notch impact
toughness. Weldability decreases. Found in the form of sulfide
inclusions.
Silicone 1% - one of the principal deoxidizers used in steel
making. In low-carbon steels, silicon is generally detrimental to
surface quality.
Phosphorus 0.04% - increases strength and hardness and
decreases ductility and notch impact toughness of steel.
Therefore, the material of our pedal is 304 Stainless steel.
DESIGN CONCEPT
After many iterations as shown below, our pedal design was selected
ITERATION 1:Rejected because it was too heavy
ITERATION 2:Rejected because it couldn’t withstand a force of 1500N
ITERATION 3:Selected since it checked in all our current goals.
- Here the two 6mm diameter holes are for throttle cable connections.
- The bottom 8mm diameter hole is for mounting the pedal.
- The other reductions are made for weight reduction.
MANUFACTURING PROCESS
- Laser cutting of all the three parts ie two side plates and one foot pedal
were done individually.
- Drilling was done in-house for all the weight reduction holes.
- Welding of all the three finished parts was done in-house as well.