Bar Stool Racer

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Bar Stool Racer
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Background Info

•   A sport that can truly be admired not only by
  young men, but also the rest of the guy's who may
  have lost their 32" waist line

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Background Info

• Many Racing Bar Stools are built as personal
  transportation at other motorsport events. 
• Others race their motorized barstools in the
  NOBRA circuit.
• They are usually a reordering or reformatting of
  go kart parts. A bar stool seats the driver and
  a special frame is constructed.
• Our racer was built out of an existing go kart
  powered by a 3.5 hp Briggs Stratton lawnmower
  motor.

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Material Selection

• The go-kart frame that we modeled our racer after
  was constructed with .75 .065 wall 1018 cold
  rolled steel. We decided on reverse engineering
  this project, starting out with an actual model
  with a chosen material and then analyzing it to
  see if it was adequate for our needs.
• We would then compare this material to other
  reasonable options available, weighing the pros
  and cons of each to come up with an appropriate
  material selection.

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Material Choices

• 4130 Alloy Steel chromoly
• Aluminum 6061- T6
• Carbon Steel 1018

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Material Pros and Cons
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Carbon Steel 1018
Pros
Cons

• Relatively inexpensive
• Can be welded or bonded by a number of processes
• Ideal for the home frame builder and mass
  production

• Weight
• Not as strong as alloyed steel
• Corrosive

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6061 T6 Aluminum
Pros
Cons

• Lightweight
• Rust resistant
• High strength to weight ratio

• 6061 T6 losses half its total strength when
  welded. Consequently, a post heat treatment
  process is required to regain it's full T6
  strength.
• Takes more skill to weld aluminum
• Cost

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4130 Alloy Steel
Pros
Cons

• High tensile strength. Considerably stronger and
  more durable than standard steel tubing.
• MIG or TIG welded.
• Better strength to weight ratio than plain carbon
  steel.

• Weight
• Corrosive
• More expensive than plain carbon steel
• When welded, a heat treating process is necessary
  to relieve stresses and regain strength.

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Material Properties
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Material Selection

• It was important to consider many factors in
  selecting a material appropriate for our
  application. Some of these factors included
  stiffness, density, cost, strength, and
  manufacturing.

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Youngs Modulus - Density
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Strength - Density
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Fracture toughness Strength
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Strength vs. Cost
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Material Performance

• Using SolidWorks CosmosXpress, we subjected the
  frame to the most extreme loading condition it
  would see to examine how each material would
  perform.
• We determined that the highest stresses would
  occur from a direct front impact at the carts
  top speed (20 mph). This would be a likely
  scenario if the cart was actually used in a
  racing circuit. Below are the dynamic equations
  used to calculate the force

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Aluminum Frame Stress Analysis
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Alloy Frame Stress analysis
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Steel FrameStress analysis
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Results

• These results showed that with our current
  design, an aluminum frame would yield from this
  impact. An optimized design might yield better
  results with this material, but that would result
  in an even greater increase in cost.
• The 4130 frame went above and beyond, resulting
  in a safety factor of 8.3. Using this alloy
  steel would not be practical for this
  application.
• The 1018 frame did not yield as well, and had an
  overall safety factor of 3.43. This was the
  material we decided to use. We then subjected
  the frame to other loading conditions, to see if
  it indeed would be an adequate material.

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Loading Condition 2

• Since the barstool racing circuit is not composed
  of the most athletic of individuals, we decided
  to test the frame for the heavier racer.
• We subjected the frame to a static load of 400
  lbs of fat man to see if our design would hold up.

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Results
The frame was more than capable of supporting
this load
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Loading Condition 3

• Next, we subjected the cart to a small jump (1
  foot, assuming both front wheels hit the ground
  first and at the same time) to see if the frame
  would bend. Since there are no suspension
  components, the entire load would be absorbed by
  the spindles and front end.

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Stress
The stress analysis shows that the frame will not
yield from this loading condition.
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Displacement
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Loading Condition 4

• Next, we applied a force to the steering support
  which would result from sudden braking or impact

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Stress
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Displacement
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Manufacturing and Assembly

• EVAN, PUT YOUR SHIT IN HERE!!!!

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MIG Welding

• Metal Inert Gas
• Typically 25-75 CO2/Ar gas mixture
• Wire feed
• Point and shoot system
• Wide range of applications
• 220V, 120V, Single Phase
• Cost effective

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Perfect MIG Weld
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Caliper Mount
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Rotor Mount
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Handlebars
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Frame weld
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Frame Welding
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3/8 Grade 5 bolts
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¾ Bolts for Spindles
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Pre-Paint
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After Paint
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Pin striping
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Burnout
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Market Analysis
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Competition
Cruzer - Barstool RacerList Price US2,995.00
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Competition
Reaper Bar Stool Racer
List Price US2,195.00
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