It didn't really take but a few hours to construct it, however, I took step-by-step pics the whole way which slowed the process down. In the end I have a crossbow that will launch a bolt more than 100' feet.
Step 1: The pieces.
Most of the components I already had on hand, such as the whiteboard, glue, screws, fork, tools etc. I went to Home Depot and Hobby Lobby for the oak strip, string, feathers and dowel. You could improvise, but I laid out a few dollars to save time and effort.
-(2) Red Oak strips 1/4"x2"x4'
-Some pieces of 1/2" thick white pine board
-Hot Glue Gun