The Roller Coaster Project

Group Members: Jonny Weigand, David Upchurch, and Jacob White

“The Pocket Rocket”

picture

Brainstorming…

Actual Design• 2 pieces• Initial drop (.5 sec)• Spiral (8 sec)• Connection to other

tubing (1 sec)• Drop (.2 sec)• Loop (.3 sec)• Downhill roll to end (5 sec)

Energy• Mass of ball = 0.0011 kg• COE for 1st drop– mgh = ½ mv2 + mgh

• COE for start of spiral– ½ mv2 + mgh = ½ mv2

• Ball stops at connection• COE for drop, loop, and decline– mgh = ½ mv2

• Energy loss from friction– mgh = Eloss

Issues

• Fitting length of tubing in constraint• Mounting supports vertically straight• Plastic tubing too stiff• Reinforced tubing too rough• Making loop with limited PE• Tubing shifting

Conclusions• Calculated speed too high• Friction of reinforced tubing• More flexible tubing• Simpler preliminary designs

The End

Construction• Procedure– Drilled 5 holes in base board for pvc supports– Cut pvc supports to length– Assembled supports on base board– Measured each guide pipe height– Zip tied the guide pipes at respective heights onto

the supports– Weaved the plastic tubing through while testing

periodically– Tested and connected bottom tubing

Construction• Materials– 1 steel ball bearing ($0.40)– 20’ of ½” pvc pipe ($8.50)– 4 ½” pvc couplings ($1.00)– 25’ plastic tubing ($5.00)– 13’ rubber reinforced tubing ($9.10)– 10 nails ($0.50)– Super glue ($1.00)– ½ m by ½ m by ½ in piece of particle board ($3.00)– 1’ of 2 x 4 ($1.00)– 50 zip ties ($3.00)– Ductape ($2.00)

Total cost = $34.50