Trebuchet of the large variety (a work in progress), 4.28.07 update

Step 6 Base: design (II) and construction (III)

The two 18' long base pieces need some method of attachment to one another (besides the treb's axle). Enter the base ends! Each base end will consist of two nearly identical components that are bolted together. The long ends of the base will slip into the channels and some sort of rod (or a realllly lengthy bolt) will attach both components. The vertical pieces you see are for diagonal braces of the main support piece; one end of the diagonal attaches here (at the base section's end) and another attaches up at the top of the of the main support.

The SketchUp file posted contains the measurements of these pieces.

Assembly time! Let's start with a cutlist (suggestions for ways to improve my cutlist presentations would be great...I'd love to use a table or something but don't I don't think Instructables has that format yet and I don't want to make people download another file):
(cut this many 8' 2x6's) at (into this quantity of these pieces)
4 at 4' 1/2", 2' 8 1/2", 8"
2 at 2x (2' 6"), 2x (1' 1 1/2") this means take an 8' long 2x6 and make two 2' 6" pieces and two 1' 1 1/2" pieces. Then repeat with another 8' long 2x6
2 at 2x (2' 3"), 2x (1' 4 1/2")
2 at 4x (1' 4 1/2"), 2x (10 1/2")

I ended up using only 8 2x6's (the cutlist above calls for 10 total) because of the large amount of scrap left over from making the main support.

The assembly of these pieces ended up being the most complicated part of the build to date. I was fortunate to escape with only one mistake (gluing/nailing two pieces that should not have been attached). For those following the plans, be extra careful in this step to check that you're attaching the right parts--many things look very similar but some components are mirror images of one another or one piece is slightly longer, etc.

It's also tricky because the nailing has to be done in a specific order due to the length of nails. Allow me to explain...first checkout the SketchUp file. The design can be aptly described as "screwy" so look at it carefully. The specific construction notes are listed in the notes on the images below--read carefully. Questions about any part of this in the comment section or a private message are completely understandable.