SLING-A-PULT
PROTOTYPE REPORT OUT
FIRST Team 20 – The Rocketeers
OVERVIEW
 Concept Overview
 Iterations (3)
 Slingshot
 Long Arm sling-a-pult
 Short Arm Sling-A-Pult
 Performance
 Spring Constant
 Conclusions
 Benefits
 Challenges
SLINGSHOT
Performance
 ~28 ft through the air with
a projectile arc
 poor control over angle
and force
 Design was reaching it’s
 Human powered water
balloon style slingshot
maximum distance with
human power
LONG ARM SLING-A-PULT
Performance
 50 ft max distance
 Distance repeatability
very good
 Large internal forces
 Design did not fit inside
the frame perimeter
 14 strands of surgical
tubing on the arm
 40” throwing arm
SHORT ARM SLING-A-PULT
Performance
 40 ft max
 Large internal forces
 Distance repeatability
very good
 Little horns on the arm
 14 strands of surgical
tubing on the arm
 32” throwing arm
SPRING CONSTANT
 Load drops off at the end of pullback
Force(pounds)
 Max load of 40lbs
50
45
40
35
30
25
20
15
10
5
0
0
50
100
Angle
150
CONCLUSIONS
PROS
 Full courting viable
 Good repeatability on
distance
 Low cost & simple
CONS
 Difficult to get equal
tension in each cord.
 Bands can wear out
 High recoil loads can
move or damage robot