1. Prepared by: Barry Sparrow and Sal Ienco Civil/Construction Sault College

2. You will need:  Balsa wood  Tape  Cutting knife  Clamps  Books  Math set  Glue  Cardboard  Pins  Sandpaper  Pencil

4. Cut accurately Take your time Be careful Total length to be 450mm Save your off cuts (scraps) Cutting Video

5. Cut both truss sides at the same time

7.  Use tape to hold parts in place  Use ‘white’ or carpenter’s glue  Be sure to glue all contact faces

9.  Be neat  Use a damp cloth or tissue to clean up  Pins can hold parts temporarily  Use scraps as spacers

10.  Check the alignment  Complete the truss gluing

11.  Use more tape to hold parts in place  Use books or similar weights to hold in place until glue has dried (1- 2 hours) Gluing Video

12.  Remove books  Cut away tape and remove carefully

13.  Remove any pins and remaining tape  Repeat process for side 2

14.  Now the truss sides can be assembled  Measure and cut the cross members  Make sure bridge is minimum width (40 mm)

15.  Glue top and bottom cross pieces in place  Line up cross members with truss webbing

16.  Use spacers or blocks to keep parts straight  Sand and trim before gluing to ensure a good connection

17.  Once the connections have glue applied the truss can be put in place  Apply glue ready for the top cross members  Use tape to keep cross members in place

18.  Install top cross pieces  Diagonal bracing installed later after glue had dried

19.  Books keep everything in place until glue sets  Spacers keep sides straight up (vertical)  Let dry for 1-2 hours

20.  Use clamps where needed to install final cross pieces

21.  To deal with compression forces, extra material is added at each truss end

22.  Adding gussets at bottom corners increases the connection strength

23.  For this bridge, diagonal bracing material was made from ½ thickness pieces, cut along the length

24.  Cut and assemble ½ thickness angled bracing  These pieces are used on each end of the bridge to keep it from collapsing sideways  Trim to size after they are in place and the glue has dried

25.  Install bracing  Note gusset added at top cross member

26.  After glue dries, bracing can be trimmed and sanded

27.  Diagonal ‘X’ bracing is installed  Cut to fit  Use pins or tape to hold in place until glue dries

28.  Install bracing on top as well as bottom of bridge  Note extra gusset at support point

29.  Bridge is complete  Touch up lightly with sandpaper  It’s ready for testing Testing Video