A brief slideshow outlining the creative journey taken thus far in improving the ts_17 halfshafts and tripods in an attempt to achieve better race car performance.

1. Team Tripods and Halfshaft
By Stefan, Laura, Adnan, Peter (S.L.A.P)

2. Introduction and Overview
• The Half-shaft and the Tripod are vital components of the
powertrain. They ensure that the output torque of the motor is
directly transferred to the wheels
• The Major components of the system include:
• The Half-shaft which is the component that connects from the
output of the gearbox to the to the wheel hub.
• Half-shaft has 2 Tripods at each end, One which slots at the end of
the gearbox the other which slots into a Tripod housings, that
coverts the torque from the half shaft, to the wheel hub.
• The plunger system is in place to account for any axial load at each
end of the tripod
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3. Design Criteria
• The Tripod and half shafts must be equal to or lower than TS_16
model, which was 3kg total (including the 4 Tripods, 2 Half-
shaft, 2 tripod housing and the internal plunge system)
• The system should be backward compatible with TS_16
• Maximum transmission angle should be less than 8 Degrees
(must justify)
• Consider the geometrical ramifications of our design and it
impact on the weight and vehicles performance
• Aim for a safety factor of 1.5-2 to ensure maximum reliability of
the system
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5. Conceptual Ideas- Tripods
• The Tripod is essentially the ends of the half shaft which fit at
the end of the gearbox and the tripod housing.
• The Tripods are essentially a 3 (tri) pointed yoke with roller ends
which help the half shaft move in the vertical axis (up and down)
to account for the suspension travel.
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6. Tripod Designs
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Standard Tripod arrangement
used in FSAE vehicles
Splined interior to lock on to half
shaft, held on with c clip
Fairly universal
Simplistic, light weight, fulfils
requirements
Stainless steel to prevent
corrosion, heat damage, chemical
damage and high strength to
weight ratio

7. Conceptual Ideas- Tripod Housing and
Grease Fitting
• The Tripod housing will connect the half-shaft to
the wheel hub
• For our design we have to ensure that the housing
has enough room to accommodate the suspension travel (25mm
which is 6 Degrees of transmission angle)
• We have to look at designing a compact design to reduce
weight and also insure the contact areas of the housing (Contact
with the tripods and shafts) are strengthen to ensure failure is
minimal.
• Addition of a Grease Fitting to ensure ease of lubricating
internals without disassembly.
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8. • Concepts
• Not backwards compatible
• Redesign whee hub and
surroundings, minimal effect on
performance
Tripod Housing and Designs
• Selected Design (similar to
ts_16)
• Aluminium outer, with alloy
steel insert, modify thickness
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9. Grease Nipple Design
• Inject Grease without
disassembly
• Dissolve any potential issue
with Galvanic corrosion
• To be constructed of
aluminium as low force
bearing component.
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10. Conceptual Ideas- Half-shaft
• The half-shaft basically converts the torque from the motor to the
wheels.
• The half-shaft is optimised in a cylindrical form (as additional
vertices increase the stress concentration factor)
• A hollow Half shaft require optimisation for the inner and outer
diameter
• For backwards compatibility, the outer diameter should remain as
20mm.
• Strong High-yield Steel alloy like 4030 300m Steel would need to be
used to avoid failure.
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11. Conceptual Ideas of the Axle Plunge
system
• The design of the half shaft is pen-ultimately effected by the design of
the plunger system. The Axial plunge system in an internal system that
is housed in the half-shaft.
• Currently consisting of carbon rod, springs and plungers, the system
works by the ends of the plungers being continuously in contact with
the walls of the gearbox and the wheel hub, as the wheel plunges (axial
movement in or out), the system keeps the half shaft free from any
external loads as well as keeps the system balanced and centred.
• Concept ideas include making the system lighter
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12. Half Shaft and Axle plunge designs
Concepts
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Hollow Shaft, Rounded Internals
Hollow Shaft straight Internals
Hollow Shaft, varying inner diameter
Hollow Shaft, rubber ceiling

13. Half Shaft and Axle plunge designs
Concepts cont.
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Complex dampening plunger concept
Hybrid Plunger design

14. Half Shaft and Axle plunge designs
Concepts
• Rubber Plunger concept
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15. Optimisation of Half Shaft
• Selecting the inner and outer diameter that ensures
the material yield strength isn’t exceeded.
• To maintain backwards capability 20mm outer
diameter has to remain.
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Excluding bending stress

16. Optimisation Graphs
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Between 10.8-14.6mm

17. Final Design and Justifications
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18. Conclusions
• We have verified to pursue a design that will meet all the
performance and safety requirements and will be effective
• Creative concept have been presented on a novel basis and
these genesis concepts have been deemed too complex or
having no impact to performance
• Our solution is neat, simplistic and compact and fits elegantly
into the SAE system
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