Kim Allen, Sam O’Flaherty, and Austin Schantz
Design
Front View
NOTE: All dimensions are in inches
3D Conceptual Design
Side View
Top View
Force Calculations
Force Calculations Continued

Known values
 Fp=250 lbs
 W=575 lbs

FS=3
FS=3
Calculated Values
 Fw=127.63 lbs
 FB=447.37 lbs
Force Calculations Continued

Max Deflection=.1 inch

From this Max strain
 εmax-B=.025
 εmax-w=.004545

If FB=447.37 lbs
Then σB=FB/A=1.553 psi
EB= σB/ εmax-B=61.32 psi=.000422787 GPa

If Fw=127.63 lbs
Then σw=Fw/A=7.977 psi
Ew= σw/ εmax=1755.12 psi=.0121GPa
Composite Design Theoretical Values

Initial Values
E1 (GPa)
E2 (GPa)
G (GPa)
ν
S-Glass Fiber/Epoxy
52.6
17.1
5.25
0.28
Closed Cell Foam
Core
.689476
.689476
.27579
0.3

Calculated Values
E1 (GPa)
E2 (GPa)
G (GPa)
ν
In-Plane Load
3.66
1.65
0.56
0.29
Bending Load
9.09
3.37
1.08
0.28

Note that the Emax =.0121 GPa. This composite
lay-up should hold
Test Section

Small section with same material layup as
project

Planned Use: Find the maximum
compressive and torsion load the layup
could withstand
Actual Use: Identify the
difficulties in
manufacturing and
bagging a 3-D project

Manufacturing

Foam Core Construction
Hot Wire
Drilling the hole for
the axle
Sanding

Foam Core

Laying Up the Foam with Glass Fiber
Composite
The Big Wheel Bagged and ready
for vacuum curing
Beginning the Lay-up

Attaching Front yoke and Preliminary Testing
Drilling Holes for Bolts
Making sure it
holds our weight
Adjusting Yolk
Making Sure it
Moves Smoothly
Making Sure it moves and
can hold extra weight
Final Product
Testing

Testing Plan
 Ride around a parking lot
 Basic turns
 Riding up a small ramp
 Test completed 3 times

Results
 Tests completed successfully
 Withstood pull-up and torsion forces
Conclusion

Successes
 Weight rated for an adult rider
 Withstood forces
 Project completed!!!!!

Failures
 Pedals slip within the hub limiting acceleration
 Metal components added significant weight
 Test section not suitable for analysis
QUESTIONS?