Trike Frame Redesign
Concept Design
Fiona Hughes
Gina Policelli
Jodie Wu
Community Partners
Response
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Biggest problem with current tricycle frames:
– (i)The Frame is not adjustable though it is made of standard
size to suit most users and small size is also available.
– (ii)It is very bulky
Reasons for current tricycle breakage:
– “Our design is made of round tubing having several bends
forming a base frame. If the tube is flattened on bending or
the material is a bit thin then it breaks easily. Also if the type
of tubing frame do not withhold the weight of the persons
then it breaks.”
Most time consuming part of building a frame: Bending the
frame
Most expensive frame material: Round hollow tubing 25 X1.5
mm for base frame.
Man-hours to produce a frame: 5 hours
Community Partners
Concerns
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Does the size and weight of tricycle cause problems for the
users?
– Yes it is bulky and weighs almost 25kg.
Are there any size limitations?
– Yes. The oversize people will have to use the stronger
material and also the tricycle has to be wider and extra large
for accommodation.
Where are the tricycles sold?
– Large number of tricycles are given free to the disabled
persons wither from the workshops or the specified project
where they are delivered for handing over.
How are they transported from the shop to the users home?
– They are transported by vehicles e.g. courier services it far
or the owners come for handing over and cycle them to their
homes.
Functional Requirements
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Strength: withstand 350 lbs of load
– Strengthen and stiffen high moment areas
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Manufacturing time: <=5 hours
Frame Materials: Cost<$200-TBD
Size: <= 50” in length and 26” in width
(including wheels)
Seat: More comfortable, adjustable,
waterproof
Shippable: Stackable Design
Defining the Concept
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Concept:
– Adjustable to the user
– Stackable Frame for shipping
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Goals:
– To address this concept by developing
modules
– Develop Most Critical Module
Our Concept and Modules
Most Critical Module:
Sturdy Base Frame
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Features/Advantages:
– Rectangular pieces
(stronger base)
– Distribution of load
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Risks:
1) Joint issues between
square and circular cross
sections
2) Attaching the stem in
terms of sturdiness
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Countermeasures:
1) Place circular pipe
against the square
pipe rather than
square pipe against
the circular pipe
2) Use a pipe fitting in
the section
Stackable Frame
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Features/
Advantages:
–
Shippable to more
clients
– Lowers shipping cost
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Risks
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Countermeasures:
1)Assemblers on receiving 1) Provide a manual
side may not be able to
(with drawings)
put trike together
2) Increase the safety
factor
2)Possible weakening of
structure
The Adjustable Seat (with hand tools)
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Features/Advantages:
– Adjustable to user
– Biomechanically
optimized
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Risks:
1) Adjustability over time
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Countermeasures:
1)Maintenance Guide
The Sliding Tray/Storage
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Features/Advantages:
–
–
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Convenience
Small Business
Possibilities
Risk:
1) May tip tricycle over
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Countermeasures:
1) Provide Counterweights,
lower center of gravity
Plan and Countermeasures
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Plan:
– Develop most critical module first
– Solid model everything
– Gather all materials and arrange lab times by
end of April
– Build Prototype
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Countermeasure:
– Build upon solid model to make a manual so
design can be constructed in machine shop in
Africa