I used Martin "Pegasus" Schmitt's plans for the pit
Tyhe plans were originally done with TurboCad.
I think you can get a trial (30 day) free version here. I converted them to a format I could open in
Corel Draw, converted metric to standard U.S. I then made the box shorter and less wide. I used Chris VanLierop's ACES II seat plans HERE in PDF. I cut it down a little as well.
I used a good full size 10" table saw to cut the parts with.