Wooden catapult built for Boy Scouts

List of materials:
2 - 2x4s
1 - 2x2 for the arm
3 - U bolts, 1 1/2"
7 - 1/4-20 by 2 1/2 inch bolts, plus nuts and washer
1 - ziploc bowl
1 - gate latch
1 - eye bolt 3/8" x 3" long plus 2 bolts and 2 washers
Some scrap plywood for the triangles
2 bungee cords 48" long
A bunch of screws, some nails
Two good sturdy boot laces for the firing mechanism and safety
1 - 1/4-20 by 2 1/2 bolt for the safety pin
Built for boy scouts

[@japiocni0km277]

I had to do one like this for school but couldn’t find a list of materials, thanks for putting them in the description