It consists of 2 A Frames with dual support along with t buttresses / stanchions on each side to keep it from racking.
The throwing arm is 25 inches with a hole drilled at the 5 inch mark for a 1/4 inch steel bar, this arm currently support a counterweight of 10lbs. The throwing basket is duct tape reinforced with a piece of fiberglass cloth. The escape mechanism is made of a coat hanger and a key chain ring. As of right now I do not have a release mechanism (works fine by hand the full size trebuchet will have to have one).
Enough prep, onto the build
Step 1: Materials and Cutting
6 5/8" x 4' dowels (there is some waste about 2ft when I was done.
6 18" - 3 for each A frame, 2 for the frame and one for the lower support
6 12" - 2 for the upper A frame supports and 4 for the stanchions.
2 24" - Support base to hold up A frame and provide a base for plank
1 1 1/2" x 14" x 1/4" launching plank (mine was a scrap piece of molding)
1 25" - throwing arm
100' of 1/8 inch jute twine or alike each lash should take about 4 ft +
Head of Arm Release
4" from coat hanger
1 Old key chain loop about 1/2 inch in diameter.
~ 9" 1/4" steel rod
4 Nylon Washers
2 1/4" end caps
Duct tape multiple pieces:
5" x 2 in.
Fiberglass cloth ~ 5" x 2" to strengthen the tape.
Zip tie and electrical tape to hold Arm release.
Hand or Chop Saw
Pliers and Cutters
1/4 inch drill