The Minnow

HOW IT’S USED

HOW IT’S USED

FOLDING HANDLEBARS

FOLDING HANDLEBARS

FOLDING HANDLEBARS

Tabs for correct handlebar orientation

FOLDING HANDLEBAR STEM

Thumbscrew

Wedge shape to avoid over rotating

FOLDING REAR WHEEL

Pivot lock

Pull both pivot locks outward to disengage pins

FOLDING REAR WHEEL

Split electronics housing to allow wheel collapse

SPRING LOADED DECK PLATE

Spring

• Spring keeps deck plate secure while the scooter is being carried

• Hinge is wedge shaped to prevent deck plate from being over rotated

INTERNAL WIRING

Materials and fabrication • Frame

Chassis

Materials: 6061-T6 Aluminum

Fabrication: Abrasive Water Jetting, Bending, Welding

Neck & Collar

Material: 356 & 6061-T6 Aluminum

Fabrication: Cutting, Grooving, Casting, Welding

• Handlebar fork

Material: 6061-T6 Aluminum

Fabrication: Cutting, Bending, Milling, Drilling, Turning, Welding

Materials and fabrication • Upper Connector

Material: 356 Aluminum

Fabrication: Casting

• Pivot Joint

Material: 356 Aluminum

Fabrication: Casting, Drilling

• Deck Plate

Material: 6061-T6 Aluminum

Fabrication: Abrasive Water Jetting

Materials and fabrication

• Wheel Guard

Material: ABS Plastic

Fabrication: Plastic Injection Molding

• Rear Pivot Locks

Material: ASTM A36 Cast Carbon Steel

Fabrication: Casting

• Electronics Housing

Material: ABS Plastic

Fabrication: Plastic Injection Molding

ASSEMBLY COST

Performance

Performance Metric Value

Stall Force (per motor)

33 lbf

Operation Force (per motor)

14.7 lbf

Acceleration 3.89 ft/s^2

Acceleration Time 5.65 seconds

Runtime 56.3 min

• All calculations done using a

• Scooter mass of 23 𝑙𝑏𝑚

• Rider mass of 220 𝑙𝑏𝑚

• Motor specifications were from the manufacturer.

• Two brushless hub motors were used in the design of the Minnow.

Maximum Grade

• Raz0r e-300 (on-the-market competitor) can handle:

• Incline of 2.88 degrees

• Grade of 3.2%

• The Minnow can handle:

• Incline of 14.32 degrees

• Grade of 15.9%

𝐹 = 0

𝑠𝑖𝑛 𝜃 + 𝜇𝑐𝑜𝑠 𝜃 =2𝐹

𝑚𝑔

Brake Performance

Performance Metric Value

Brake Force 325.9 lbf

Brake Time 0.51 seconds

Brake Acceleration -43.12 ft/s^2

Braking Distance 5.61 ft

• The Minnow uses a 3.15 inch band brake

• Actuation force calculated from 60% of the average max grip strength of a 18-29 year old.

Finite Element Analysis • All parts underwent Finite Element

Analysis (FEA) in SolidWorks as they were designed.

• Each part is designed to have a minimum factor of safety of 3.

Thermal Analysis

• Motor Analysis

• Temperature increase of 0.6 °𝐹 in the motor during acceleration from zero to max speed of 22 𝑓𝑡

𝑠

• Brake Analysis

• Temperature increase of 47.5 °𝐹

• Assumes worst cases:

• No heat is transferred while braking

• Force applied instantaneously

ELECTRICAL SYSTEMS

COST

Cost Category Cost

Direct Costs -

Manufactured Parts $102.50

Commercial (off the shelf) $315.03

Assembly (direct labor) $9.16

Total Direct Costs $426.69

Indirect Costs $213.35

Total $640.04

Sales Price $1,299.00