Egr 102

Final Design Project

Catapult Design

• Goals:– Shoot a ping pong ball exactly 100.0 cm

(measured from the front of the catapult)– Score based on precision (consistency)–3 shots in final competition.

• Requirements:–Material: Popsicle sticks, glue, and rubber

bands–Budget: max $10 per group

• If rules not followed, cannot participate in the shooting

Catapult Design

• Requirements:–Allowed material: • Popsicle sticks – same size actually found

in popsicles• Rubber bands – any kind• Glue – any kind, I recommend hard drying

glues such as epoxy• No other materials allowed• You may cut, bend, drill, etc. the

materials

Catapult Design– Budget: max $10 per group.• This is total development budget, not just cost

of final product• Copy receipts to report to prove you stayed

within budget, include explanation of materials obtained for no cost.• Can share costs with other groups• A.C. Moore sells a bag of popsicle sticks for 99

cents• You may use items and tools found at home for

no cost (only allowed materials)

Shooting

–Scoring based on accuracy•Average of successful shots• Target zone set up 90 cm to 110 cm

from front of catapult. 10 cm wide.•Only shots that land in target zone

count.

Shooting Details

• You will be allowed to hold down your catapult to the table such that the front of the catapult is 90 cm from the start of the target zone.

Scoring Details

• The point of impact of the ball with the table will be determined by spreading flour or sand on the table. • It does not matter where the ball

rolls after initial impact.

Scoring Details

• The optimum point of impact is at a range of 100 cm with no deviation to left or right.• Deviation of 5 cm to left or 5 cm

to right is allowed.

Scoring Details

• A ball landing in the target zone at 100 cm receives a score of 100!• A ball landing in the target zone

at 95 cm receives a score of 95.• A ball landing in the target zone

at 105 cm receives a score of 95.

Scoring Details

• The total score of the three shots is found by adding the three scores together.• Balls impacting outside of the

target zone receive a score of 0.

Scoring Details

• A perfect score for three shots is 300!• In the event of as tie, there will

be a runoff match.

Written Report

• 7 Page minimum report must be submitted on day of final examination.• Report must include:–Title Page–Abstract

Written Report

–Introduction–Literature Review–Design including mathematical

calculations and iterations from model mark 1 to final model–Discussion–Conclusions–References

Written Report

• Must include:–Calculations–Diagrams–Photographs–Schematic Diagrams with

dimensions