Trebuchet Build Instructions

Trebuchet Build Instructions 1. Make sure you have both parts to your kit: 1. a box 2. a taped bundle. Note: • complete this build only under adult supervision • be careful of wood splinters and sharp ends on screws. 2. arrange all the parts out on a table as shown below. 1 *Important: complete a “dry” build first without glue to ensure you assembly is correct. The label, mark or simply remember and re-­‐assemble with the PVC glue/cement in a well ventilate area under parent-­‐guardian supervision. 3. build ½ of the trebuchet. All the connecting joints use the shortest 2” (5cm) long pipe sections 12 short pipes; 6 for each side. 4. Build the 2nd ½ identical to the first so you 2 halves. Then stand them up side by about a foot (30 cm) apart. 5. Then place the two 12” pipes here: 2 6. Insert the 12” (30 cm) pipes into the Ts. 7. Now build outer stabilizers with 4 caps and 4 short pipes (4”) DO NOT USE THE CAP WITH THE HOLE IN IT (you will need it later)! cap 4” (10 cm) pipe Now you should have a stable platform. 8. Insert pre-­‐assembled throw arm into the top 2 Ts. Have wood brace to top for less interference with weight. Make sure it swings freely. You can lubricate the joint with cooking oil later. Wait until all the glueing is completed as oil could interfere with a glue bond. 3 9. Gather the cap with hole and screw. 10. Remove the nut and insert the screw from the inside of the cap. Place the nut on the outside and tighten it with pliers. 11. Glue the cap with tighted screw onto the end of the pre-­‐assembled throw arm. 12. Place the long, wood board in the center with the longest end matching the long end of the pre-­‐assembled throw arm. Use the 4 short, black zap straps to fasten it to the bottom pipes. board sticks out same side as throw arm. Opposite end is flush with bottom pipe. 4 13. Notice the 2 screws on the end of the board. Cut a piece of string about 12” (30 cm) long. Tie one end securely with a few wraps to the screw with the head. With the other end of the string make an overhand loop. That string will go from the board, across the throw arm, and back down to the board where the loop will catch on the headless screw. This is your firing mechanism. Attach another string to the loop to pull it off the headless screw to FIRE your trebuchet. This is where you can experiment a bit with string length. You can also use a washer if you like to catch on the headless screw as it will slide off easier when you want to fire your trebuchet. See set 12 on page 4. 14. Attach your counter weight with large zap strap (or a piece of rope which you will have to supply). This is tricky and this will require more than one person. I used my lunch box. I have a large farm appetite so I pack a hefty lunch (lots of meat – GRRR). Tie here. 15. Make the pouch with a piece of fabric of a dishcloth and 2 pieces of string. Tie the string to one corner; then tie the other end to another corner. Repeat the process on the other side. Make sure they are approximately the same size. Tie here Tie here Tie here 5 16. Then make up 2 more strings about 2’ to 3’ (60 cm to 90 cm). Tie each of them to the strings you just tied to the pouch. Tie here Tie here Your pouch should hang like this with the ball in it (like an up-­‐side-­‐down parachute) 17. Now tie one string tightly (make a few wraps) to the screw on the of the throw arm. With other string, make an overhand loop. The strings have to be adjusted to the pouch hangs properly even so the ball does not fall out. 6 Your loaded trebuchet should look like this. Experiment with: • weight: add sand and water • string lengths on sling • screw on end of throw arm: if you bend it one way or the other, it will affect release point in the throw. Watch these youtube videos to garnish ideas and enthusiasm. http://www.youtube.com/watch?v=Cm-­‐AZSkzdxo&list=PL044FC80580FA40BC http://www.youtube.com/watch?v=rXSpmxrCEn4 http://www.youtube.com/watch?v=CyCJ69GU974 7 8