Fully working C Clamp with 4 different movable parts. The clamp opens to just under 2". If you print this model to scale you will need a high resoultion printer capable of printing an easily removable support material (or else it will be impossible to free up the threads). The clearances in the threads are the smallest at about 0.006" at minimum. If needbe you can scale up this design when you print it to increase the clearances.

I printed a couple of these on an objet polyjet-style printer and they worked great. Freeing up the threads was a little tricky and required applying torque in both directions, over and over, until the support material finally let go.