Trial One

• Full-sized sling
• Long strings
• Sides of sling were not stapled yet
• Longer nail on top of throwing arm where the sling attaches
• Ball flew out of sling backwards, which meant that it was releasing way too early

Trial Two

• Minor adjustments
• Made strings a little shorter, but still too long
• Cut the sling down to half of its original size
• Ball slipped out of the sling before it even made it in the air
• We decided to move the trebuchet into the shade facing the street because at that point we were pretty sure that nothing would launch far enough to hit anything

Trial Three

• Final Launch
• Sling hangs down to right above the axle of the throwing arm when arm is up
• Changed the sling from lying down horizontally to lying down vertically
• Ball was released at just the right time and flew across the street, which was over 25 feet