We all love K'nex, but wouldn't it be great if they were WAY bigger and made of something other than plastic? All you need to make Giant Bamboo K'nex i a drill, saw, two big drill bits (or hole saws), a chisel, and a hammer, oh and of course some bamboo.
Step 1: Cut
Start by cutting the bamboo to length. I used 3 or 4 node lengths for each piece. It is important to cut the bamboo just before the next node in order to give yourself enough room to work in.
Step 2: Drill
Next, drill two holes in the bamboo. One hole should be close to the end, and about a half inch smaller than the bamboo it's self. The other hole should be smaller by about a quarter inch and placed close to the next node.
Step 3: Chisel
Being sure to not get too close to the full size of the first hole, use the chisel to cut out some pieces at the end of the bamboo piece. This will eventually be where this piece attaches to another.
Step 4: Cut
Using a straight edge or ruler, mark a center line on the bamboo. Next, draw two more lines on each side, that go from the outer edge of the inner hole to the center of the outer hole. Cut down each of these lines with a jig saw or hack saw.
Step 5: Grind
In order to smooth out the ends of the bamboo, the best method I found was to use a sanding wheel on and angle grinder. Grinding will make the connection to other pieces easier and also improve the look and safety. Repeat all steps on both ends of each piece.
Step 6: Enjoy
Now you can build all sorts of fun stuff. I don't recommend trying to make anything super structural with this joint, but it is a pretty fun toy. Once I have access to a rotary axis cutter again, I plan on making a more precise version with slightly more complex geometry.