In this video I go over how to make a buck saw out in the woods using just a saw blade and some rope. The frame of the saw is constructed from wood you collect in the bush. The only tool you need for the job is your knife, although an axe will help when collecting the wood.
Here are some pictures of the finished product.
It is not pretty, but worked very well. The whole video of me making the saw was 35 minutes in length, including all the set up time for the camera. I would estimate that it took me about 30 minutes of actual work time to complete the saw. Of course that does not take into account the 15 minutes or so it took me to find the type of wood I needed. In this case I was using oak, but any strong wood will do the job.