New Endpin Installed: Test Launch

• New endpin has been installed.
• Balloons' weights not measured and distances approximated. This test is only for observations of any noticeable improvement.
  

Test 1

• CW Prop Angle: 180
  
• Appx. Distance: ~90ft

Test 2

• CW Prop Angle: 180
  
• Appx. Distance: ~90ft

Test 3

• CW Prop Angle: 180
  
• Appx. Distance: ~90ft

Test 4

• Tennis Ball Weight: 56g
  
• Tennis Ball Name: Wilson
  
• CW Prop Angle: 180
  
• Appx. Distance: ~90ft

Observations/Conclusions:

• The trebuchet's accuracy is now highly accurate, with every projectile landing in almost the exact location.
• The throwing distance has not been improved.
• Sling is being released too late. Angle of endpin needs adjusted.

Modifications

• Potentially dangerous bolt protruding from bottom of throwing arm has been trimmed.

Future Plans

• Endpin can't be adjusted. New one will need to be made.

New Endpin

A new endpin as been created using a 2in pin compared to the previous 1in pin. The angle of the pin is 30 degrees. It will be tested once the glue has dried.

Endpin modification test launch

• Launched from ground level
• Projectiles: Water balloon, tennis ball
• This was just a test to visually see if the modification made any difference. The balloon distance was approximated. The tennis ball's distance was not measured.
  

Test 1

• Balloon Weight: Not Measured
  
• Balloon Launcher: Rosa
  
• CW Prop Angle: 180
  
• Total Distance: Appx. 90 ft.

Test 2

• Tennis Ball Weight: 56 g
• Launcher: Adam
  
• CW Prop Angle: 180
  
• Total Distance: Not measured

Test 3

• Tennis Ball Weight: 56 g
  
• Launcher: Rosa
  
• CW Prop Angle: 180
  
• Total Distance: Not measured
  

Conclusion:

• The modification did not improve the trebuchet. It's performance was about the same if not slightly worse.

Next Time:

• Create new, longer endpin.

Endpin Modification

Took endpin piece to Bob to be modified.  Pin was removed successfully from the endcap, and bent a few more degrees.  Endcap broke while trying to replace the pin.  Glued together.  Will wait a few days before launching.

Day 16: Physics Camp

Launched balloons from 4th floor at Physics Camp students. Only one balloon's distance was approximately measured.

Test 14

• Balloon Weight: 51 g
  
• Balloon Name: Sue
  
• Balloon Launcher: Adam
  
• CW Prop Angle: 180
  
• Appx. Distance: ~43 m

Record Breaker!

Day 15

Test 1

• Balloon Weight: 173 g
  
• CW Prop Angle: 180
• Distance to Rail: 19.1 m
  
• Distance from Building: 5.95 m
  
• Total Distance: 25.05 m
  

Day 14: A Contest

Today we had a contest to determine who could launch a balloon the farthest.

Distance to rail: 19.1 m

Test 1

• Balloon Weight: 164
  
• Balloon Name: Gracie
  
• Balloon Launcher: Rick
  
• CW Prop Angle: 160
• Distance from Building: 4.64 m
  
• Total Distance: 23.74 m
  

Test 2

• Balloon Weight: 167
  
• Balloon Name: Monti
  
• Balloon Launcher: Rosa
  
• CW Prop Angle: 180
  
• Distance from Building: 6.15 m
  
• Total Distance: 25.25 m

Test 3

• Tennis Ball Weight: 56 g
  
• Tennis Ball Name: Wilson
  
• Balloon Launcher: Adam
  
• CW Prop Angle: 180
  
• Distance from Building: 9.3 m
  
• Total Distance: 28.4 m

Winner in the Balloon Category: Rosa
Winner Overall Today: Adam

No one beat Rosa's All Time Record of 36.9 m


Planned Future Modifications:

• Change the pouch.
• Modify overall slinging apparatus.
  
• Build a second trebuchet with metal throwing arm.

Day 13: Frozen Donuts

Tossed donuts frozen in liquid nitrogen

Test 1

• CW Prop Angle: 180
  
• Distance: 22.69 m

Test 2

• CW Prop Angle: 180
  
• Distance: 26.81 m

Test 3

• CW Prop Angle: 180
  
• Distance: 35.95 m

Test 4

• Launched two donuts frozen together
  
• CW Prop Angle: 180
  
• Didn't measure
  

Day 12: Round 2

Test 15

• Balloon Weight: 270 g
  
• Balloon Name: Cookie
  
• CW Prop Angle: 180
  
• Distance: 13.15 m

Test 16

• Balloon Weight: 177 g
  
• Balloon Name: Champ
  
• CW Prop Angle: 180
  
• Distance: 26.75

Test 17

• Balloon Weight: 226 g
  
• Balloon Name: Monster
  
• CW Prop Angle: 180
  
• Distance: 17.5

Test 18

• Balloon Weight: 321 g
  
• Balloon Name: Py
  
• CW Prop Angle: 180
  
• Distance: ~ 3.5 m

Test 19

• Balloon Weight: 191g
  
• Balloon Name: Dirty Ho
  
• CW Prop Angle: 170
  
• Distance: 26.25 m
• Michelle's Theory: Pink balloons go farther.

Test 20

• Balloon Weight: 320 g
  
• Balloon Name: Victor
  
• CW Prop Angle: 170
  
• Distance: ~ -.5 m

Test 21

• Balloon Weight: 202 g
  
• Balloon Name: Ernie
  
• CW Prop Angle: 180
  
• Distance: 19.35 m

Test 22

• Balloon Weight: 222 g
  
• Balloon Name: Steve
  
• CW Prop Angle: 175
  
• Distance: 19.65m

Test 23

• Balloon Weight: 291 g
  
• Balloon Name: Lennie
  
• CW Prop Angle: 165
  
• Distance: ~ -1.5 m
• Hit the table
• Scared Michelle and got her wet.

Test 24

• Propped track on base
  
• Balloon Weight: 220 g
  
• Balloon Name: Elmo
  
• CW Prop Angle: 180
  
• Distance: 18.6 m

Test 25

• Replaces track in former position
  
• Balloon Weight: 168 g
  
• Balloon Name: Bruce
  
• CW Prop Angle: 175
  
• Distance: 25.55

Test 26

• Balloon Weight: 184 g
  
• Balloon Name: Mig
  
• CW Prop Angle: 180
  
• Distance: 22.05 m
  

Test 27

• Balloon Weight: 242 g
  
• Balloon Name: Bert
  
• CW Prop Angle: 175
  
• Distance: 19.15 m

Test 28

• Balloon Weight: 192 g
  
• Balloon Name: Awesomeness
  
• CW Prop Angle: 175
  
• Distance: 25.62

Test 29

• Balloon Weight: 1114 g
  
• Balloon Name: Big Bird
  
• CW Prop Angle: 175
  
• Rolled backwards out of pouch and popped

Test 30

• Tennis Ball Weight: 56
  
• Tennis Ball Name: Wilson
  
• CW Prop Angle: 175
  
• Distance: 27 m

Test 31

• Tennis Ball Weight: 56
  
• Tennis Ball Name: Wilson
  
• CW Prop Angle: 180
  
• Distance: 26.75 m

Test 32

• Tennis Ball Weight: 56
  
• Tennis Ball Name: Wilson
  
• CW Prop Angle: 175
  
• Distance: 18.75 m

Day 12

Launched from the 4th floor
Distance to 4th Floor Rail: 5.3 m

Test 1

• Balloon Weight: 435 g
  
• Balloon Name: Fatter Bastard
  
• CW Prop Angle:180
• String got caught in pin holding eye rings.
• Balloon didn't pop.
  

Test 2

• Fixed string
  
• Balloon Weight: 435 g
  
• Balloon Name: Fatter Bastard (take 2)
  
• CW Prop Angle: 180
  
• Went straight up.
• Adam got a little wet.
• Distance: ~1.5 m
  

Test 3

• Balloon Weight: 391 g
  
• Balloon Name:Fat Bastard
  
• CW Prop Angle: 180
  
• Ring slipped off.
• Balloon didn't pop.
  

Test 4

• 
  
• Balloon Weight: 391 g
  
• Balloon Name: Fat Bastard (take 2)
  
• CW Prop Angle: 160
  
• Distance: 7.3 m
  

Test 5

• Balloon Weight: 228 g
  
• Balloon Name: Verde
  
• CW Prop Angle: 180
  
• Distance: 19.55 m
  

Test 6

• Balloon Weight: 163 g
  
• Balloon Name: Azul
  
• CW Prop Angle: 180
• Distance from building to rail (2nd floor) : 18 m
• Distance from building: 8.9 m
• Total Distance: 33.5 m
  

Test 7

• Balloon Weight: 134 g
  
• Balloon Name: Pepto
• CW Prop Angle: 180
• Distance from building: 7 m
  
• Distance: 31.5

Test 8

• Balloon Weight: 46 g
  
• Balloon Name: It
  
• CW Prop Angle: 180
• Distance from building to rail (2nd floor): 15.85 m
• Distance from building: 6 m
  
• Total Distance: 28.35
• Balloon Didn't pop
  

Test 9

• Balloon Weight: 46 g
  
• Balloon Name: It (take 2)
  
• CW Prop Angle: 180
  
• Didn't measure distance
  

Test 10

• Balloon Weight: 203 g
  
• Balloon Name: Green Bomber
  
• CW Prop Angle: 180
  
• Distance from building: 1m
  
• Distance: 23.7 m
  

Test 11

• Balloon Weight: 46 g
  
• Balloon Name: It (take 3)
  
• CW Prop Angle: 180
• Distance from building: 7 m
  
• Distance: 30.7 m
  

Test 12

• Balloon Weight: 660 g
  
• Balloon Name: Fattest Bastard
  
• CW Prop Angle: 180
  
• Distance: ~ -3.5 m
• Height hit on building: ~ 2 m
• Went backwards and hit building
• Balloon was too heavy
  

Test 13

• Balloon Weight: 266 g
  
• Balloon Name: Red Baron
  
• CW Prop Angle: 180
• Distance: 13.0 m
  

Test 14

• Balloon Weight: 165 g
  
• Balloon Name: Woodstock
  
• CW Prop Angle: 180
  
• Distance: 31.1 m
  

Conclusion: Balloons heavier than 391 g don't fly.

Day 11

Modifications:

• Added new CW hanging bars (13")
  

Test 1

• Balloon Weight: 167 g
• CW Prop Angle: 175
• Distance: 36.9
  

Test 2

• Tennis Ball Weight: 56 g
• CW Prop Angle: 180
• Distance: ~18.5 m
  

Day 10

Schematics for new CW hanging rods given to Bob. Not added to trebuchet yet.

Test 1

• Balloon weight: 173 g
• CW Prop Angle: 160
• Distance: 16.45 m

Test 2

• Balloon weight: 260 g
• CW Prop Angle: 180
• Went backwards and hit building.

Test 3

• Balloon weight: 324 g
• CW Prop Angle: 135
  
• Distance: 9.3 m

Test 4

• Launched a tennis ball instead
  
• Tennis ball weight: 56 g
• CW Prop Angle: 175
• Distance to Rail: 19.10
• Distance from Building: 7.05
  
• Total Distance: 26.15 m
  

Day 9

No launches today.

• Rick has a metal pole we can use for a new throwing arm.
• Plan on using a tennis ball to keep projectile mass constant for testing.
• New schematics drawn to give to Bob for new CW hanging bars.
• Plots made of data (will be added later)
  

Day 8

No launches today.

Attempted to do video analysis on previous launches, however the video analysis software did not like the video files in either mpg or mov formats.

Day 7

Modifications:

• Taped lid onto counterweight can.

Test 1

• Balloon Weight: 94 g
• CW Prop Angle: 180
• Distance: 27.68 m (drop in height from building not accounted for)
• Building Height: 6.45 m
• Railing Width: 0.43 m
• Distance to Rail: 18.2 m
• Distance from Building: 9.05 m
• Group of people sat around landing spot. Asked to move.
  

Test 2

• Balloon filled with ~25% water, ~75% air
  
• Balloon Weight: 209 g
• CW Prop Angle: 180
• Distance: 17 m
  
• Almost hit Adam

Test 3

• Balloon Weight: 187 g
• CW Prop Angle: 180
• Distance: 18.6 m
• Landed on rail.

Planned Modifications:

• Replace PVC throwing arm with metal pole.
• Glue knots in strings.

Day 6

Modifications:

• Changed launching direction (launch from NE to SW). Wind in favor.
• Made certain of proper alignment of track.
  

Test 1

• Balloon Weight: 166 g
  
• Distance: 14.58 m
  

Test 2

• Balloon Weight: 134 g
• CW Prop Angle: 165 +- 5
  
• Distance: 24.72 m (drop in height from building not accounted for)
  
• Height of Building: 7.27 m
• Went over railing. Rick owes us a pop!
  

Test 3

• Balloon Weight: 264 g
• CW Prop Angle: 180 +- 5
  
• Distance: Traveled straight up and backwards over rail.
• Sling ring disconnected
  

Test 4

• Reset Ring
  
• Balloon Weight: 143 g
  
• CW Prop Angle: 155 +- 5
  
• Distance: -3.5 ft
• Slipped out of sling
  

Test 5

• Balloon Weight: 143 g
  
• CW Prop Angle: 155 +- 5
  
• Distance: -
• Sling disconnected (untied)
  

Test 6

• Sling reconnected
  
• Balloon Weight: 143 g
  
• CW Prop Angle: 155 +- 5
  
• Distance: 7.46 m
  
• Veered left
• Balloon didn't pop
  

Test 7

• Reset track
• Rick Launched
  
• Balloon Weight: 155 g
  
• CW Prop Angle: 160
  
• Distance: 28.42 m (drop in height from building not accounted for)
  
• Height of Building: 7.27 m
• Balloon didn't pop

Conclusion:

• Propping the counter weight greatly increases the throwing distance.
  

What to try for next time:

• Change throwing arm (more durable) to add more weight
• Glue strings' knots.

Day 5

Modifications

• Replaced strings holding counter weight can with 5.25 in. metal bars.
• Shortened bolts on base that hold the pin (so the trebuchet can sit flat).
• Trimmed base PVC pipe that holds pin bolts.

Test 1

• Sling released too soon
• Balloon went backwards

Test 2

• Reset.
• Same results.

Test 3

• Reset.
• Same results.

Test 4

• Used larger balloon.
• Sling released too soon.
• Balloon went backwards, popped.

Test 5

• Added v-shaped metal track.
• Success! Balloon hit wall on opposite side of balcony (appx. 15 m) before bouncing away.

Test 6

• Used balloon with thinner rubber.
• Same results as above. Balloon popped.
• Traveled 15.27 m.
• Was launched at slight angle to the right of the trebuchet. Possibly caused by misaligned track.

Conclusion: Adding the v-shaped metal track greatly improved the performance of the trebuchet. What to try next time:

• Properly align the track.
• Prop the counterweight.

Photos:

Day 4

Trebuchet launching canceled due to rain.

Modifications:

• Shortened sling string length to 4 ft.

Planned Modifications:

• Replace string holding counterweight with metal bar.
• Trim base PVC pipe that holds pin bolts.
• Possible modifications to trebuchet throwing arm.
  

Day 3

The first launching

Test 1

• Balloon went backwards and over the railing.
  

Test 2-4

• Balloon either went backwards or a few meters forwards.
  

Test 5

• Balloon was launched a few meters and bounced a few more.

Test 6

• Balloon was launched backwards landing on balcony barrier.
• Trebuchet begins to fall apart.
  

Test 7

• Pin got stuck on launch causing misfire. Possibly caused from pulling from an angle.
  

Test 8

• Pulled pin directly perpendicular to the holding bolts.
  
• Balloon went appx. halfway across the balcony and bounced it's way towards the end.
• Trebuchet falls apart.

Conclusions:

• The trebuchet needs to be glued together to hold up for multiple launches.
• Problem with the launch is either caused by the sling, the counterweight, or both.
  

What to try next time:

• Modify sling pouch.
• Shorten sling string.
• Add more weight.
  

Modifications:

• Glued trebuchet together.

Day 2

The throwing arm, the base piece for the eye bolts to hold the throwing arm down, and the counterweight holder (coffee can) are given to Bob to be drilled.

The sling is planned to be made from denim.

Day 1

Purchased ~$50 worth of materials for the trebuchet construction:

• 5 PVC pipes
• 8 T-joints
• 8 45 degree joints
• Purple Primer
• PVC Glue

The PVC pipe was cut the following way:

• 2 4" pieces (throwing arm axel holders)
• 4 4" pieces (to hold together T-joints)
• 1 7' piece (throwing arm)
• 2 7' pieces (base)
• 2 20" (base)
• 4 51" (supports)

The following are the models being used to as a guide to build our trebuchet:
http://web.archive.org/web/20070722115351/http://www.ripcord.ws/plans/plans.html
http://www.redstoneprojects.com/trebuchetstore/pvc_trebuchet_2.jpg