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

Step 3 Base: construction (II)

If you recall, the plan was to connect all of these base pieces (like the rest of the trebuchet) with bolts. I somewhat arbitrarily chose 5/16" diameter bolts. They're 5 1/2" which was the minimum length to fasten three 2x6's face to face to face. Washers and nuts corresponding to the 5/16" diameter were also purchased. I initially thought of putting four bolts through every 16" overlap (totaling to 8 bolts per joint). In retrospect that qualifies as excessive--it'd require 32 fasteners all in all. I ended up buying half that and two extra (18 total) for two bolts per connection plus spares. On to drilling!

It'd be nice if any of the red/purple base pieces could go with either of the blue pieces. Part labeling would not be required and assembly would likely be simpler. To attempt this Herculean task I made a little drilling jig out of a spare 2x6. I would use four holes in this piece to align the bit when drilling the red, purple, and blue pieces. This ended up failing for two reasons. (1) I didn't measure the holes in the jig. They would need to be exactly symmetrical about both axes for any red/purple piece to fit with any blue middle section. (2) None of the red/purple (should I just start calling them rurple?) pieces were "exactly" the same meaning the jig aligned on them differently. Things won't fit if they're off by more than 1/8" or so, so another method was chosen. Press on!

Giving up on interchangeable components, I started drilling one part with the jig (let's call this part A). The piece intended to fit with A was then drilled using part A as a template for the second. All pieces were labeled.

Final note (apologies for the wordiness of this step): Though my bolts were 5/16" in diameter, I drilled holes for them with a 3/8" bit (1/16" larger). This made actually putting the bolts in far easier.