160 likes | 306 Views
San Diego Regional. Ping Pong Parachute. The Goal. Design, build, and test up to two bottle rockets to launch a ping pong ball with a parachute to achieve maximum time aloft. You will need…. A Rocket (or 2) A Parachute with Ping Pong Ball (or 2) A Practice Log. You may bring….
E N D
San Diego Regional Ping Pong Parachute
The Goal Design, build, and test up to two bottle rockets to launch a ping pong ball with a parachute to achieve maximum time aloft.
You will need… • A Rocket (or 2) • A Parachute with Ping Pong Ball (or 2) • A Practice Log You may bring… • A Pump & Pressure Gauge SO will provide… • The Launcher • A Pump & Pressure Gauge if needed
Rocket Bottle • Construct from 1-liter bottles (3a) • Plastic, carbonated beverage bottle • Nozzle: 2.2 cm internal diameterFit ½ inch Schedule 40 PVC pipe • Neck: 1.6 cm length from flange to opening
Rocket Dimensions • Rocket nose must be rounded/blunt at the tip (3c) • No parts within 5cm of opening (3e) 3.1 cm diameter 1.25 cm tall Rule 3c: Nose must not touch inside of bottle cap Rule 3e: No fins or anything else in these 5 cm
Rocket Construction • Attachments to the bottle must use tape (3d) • Nothing that can alter the structural integrity of the bottle is allowed (3b), e.g. no cutting, no hot glue • Only air pressure can be used to launch the rocket • No water, chemical reactions, electrical devices, etc. (3f) • Building Policy • Expect the Event Supervisors to ask questions regarding rocket design and construction.
Practice Log • At least 5 parameters • At least 15 flights • FIXED • Most useful for competition day: • Find best pressure • Highest peak altitude • Minimize chances of hitting the ceiling • SELECTED • Best for designing rocket: • Number of fins • Parachute diameter • Parachute shape • Parachute weight
Launchers and Pumps • Pump may be provided by the team • Launcher will connect with Shrader Valve • Launchers: • https://www.nerdsinc.com/products • https://www.amazon.com/Bottle-Water-Launcher-trigger-Shipping/dp/B01N9VPW79
Competition – Pre-Launch • Eye protection “B” is required – Z87+ • Rockets will be inspected for safety AFTER teams come with proper eye protection (4a) • DURING inspection, teams must present a flight log • Teams without a flight log cannot compete (4b) • Teams USE flight log data pick a pressure choice that ensures the rocket won’t hit the ceiling • A good flight log is key to them allowing teams compete.
Competition – Launching • Teams get 5 minutes for 2 launches • Either 1 rocket twice or 2 rockets once each • Launching: • Load rocket on the launcher. • Before pressurizing, place the ping pong ball and parachute into/on the rocket. • Don’t mess this up! Ball and parachute placement is important! • Teams pressurize their rocket. • No rocket manipulation can happen once this starts. • Event Supervisor will check the pressure gauge. • When everyone is ready, 1 team member launches the rocket.
Competition – Timing • Timing STARTS when the rocket leaves the launcher • NOT when the team member yells “LAUNCH!” • If there’s any mishap and the rocket doesn’t launch, the team should get another try. • Timing ENDS when: • the rocket or parachute touches the ceiling, oranything attached to the ceiling => Tier 3 • the unseparated rocket and ping-pongball touches the ground => Tier 2 • the separated ping-pong balltouches the ground => Tier 1
Scoring • Ranking is determined by the greatest time aloft of a ping-pong ball during a SINGLE launch. • Ties are broken by each team’s OTHER launch • Times are measured to the nearest 0.01 seconds. • 3 Event Supervisors must time each run. The median time measurement is the officially recorded time.
Venue • Miramar • Student Services Foyer (tentative) • 13.5 Meter ceiling • USD – Not announced
Suggestions • Minimize weight for maximum altitude • Focus on designing a good parachute • Circular parachutes have the most surface area/material • Materials: Rip stop nylon, drop cloth, garbage bags • Focus on separation • Passive: parachute falls off at apogee • Active: mechanical system pushes parachute out • Focus on parachute inflation • Catch air as quickly as possible
Resources • Problem Solving / Technology CD • Ping Pong Parachute Digital DVD • www.soinc.org/ping-pong-parachute • www.soinc.org/events/rules-clarifications • scilympiad.com/san-diego-so/QnAs • scioly.org/forums/viewforum.php?f=317