This is the k'nex sword I designed a year or so ago. I've upgraded the hilt since then. I recommend not building this if you don't think that you'll be able to deconstruct it, as that is the main problem. Because of how strong it is, the full picture is only 2/3 of it. I have on side serrated mainly to save on the yellow connecters, but if you don't want a serrated edge just replace all the yellow connectors with the pegs with ones without one.
Step 1: Total Pieces
green rods: 223
white rods: 122
red connectors: 5
green connectors: 6
yellow connectors: 111
white connectors: 28
15 of the yellow connectors can be replaced by the ones with the peg on the back if you want a serrated edge.
Step 2: Hilt
I will not put any of the white or green rods on the outer layers until the end so that mistakes are easier to fix.
Step 3: Crossguard
Step 4: Blade
This is the largest step and is rather hard on the fingers. If you don't want the serrated edge, use normal yellow connectors instead of the ones with the pegs on the back.
Step 5: Connecting It All
Now to add them all together. You will have to temporarily remove a few pieces to connect everything, which is why I didn't put the green or white connecters on the outer layer.
Step 6: Adding the Rest of the Pieces
For the rest of them, just put them where the gaps are. I would of shown how, but I had to make sure I could disassemble this after.