Warren Truss

 28 October 2021

• Over the side profile of the fuselage, draw warren truss lines.
• Prepare strips of foam, lay down in one direction.
• Prepare strips of foam, lay and glue in the other direction. It is lap jointed to the first direction pieces.
• Lay and glue a side strip from nose to tail. This side strip is glued lap jointed to the second direction pieces.
• Cut the lattice to side profile, less thickness of outside edge.
• Remove from plan and glue another side strip to lattice pieces of the first direction.
• Glue edge strips around the lattice. 

Edge strips can be paper, card, foam, balsa.

In the simplest form, it is a I-section beam with side beams.

Side strips would preferably be from foam or balsa because some strength is needed. There may be more than one side strip on one side of the profile. 

Not Warren Trussed, a ladder framed I beam:

• Lay side strip on side profile.
• Lay and glue cross strips over side strip.
• Lay and glue another side strip.
• Cut cross strips to side profile, less edge strip thickness.
• Glue edge strips around ladder frame.

Why this method: lapped joints maximised resistance so it is equally strong and it is easier to make, easy to place reinforcement pieces, even if edge strips are weakened, the side strips are the main load bearers.