The threaded shaft and nut on the pliers require a very well tuned printer, such that the outside diameter of the threads closely matches the inside diameter of the nut. My MakerBot is not so well tuned, and prints shafts a fraction of a mm smaller than desired while printing holes the same amount larger than desired. The full size nut slipped right on/off, so I shrank it to 90% (in X and Y, no shrinking in Z) and printed it again, then all was well. Also included below is an 80% version, which was too small for my pliers but may come in handy for someone with a worse tuning problem than I had.

Use this nut with the other parts of http://www.thingiverse.com/thing:1091