The file '2 Liter Bottle To 1/2″ PVC Pipe Adapter 3D Printer Model' is (stl) file type, size is 32.6KB.
In keeping with Kludgemonkey's wishes (http://www.thingiverse.com/thing:13826), this is a remix of his Bottle Cap Start that adapts a bottle cap to a piece of 1/2" PVC pipe.
I used it to make the HowToons Stomp Rocket from MAKE Magazine volume 42. Instead of duct taping the bottle to the PVC pipe, the bottle screws onto the adapter, which fits on the PVC pipe. This way the smashed bottle can be unscrewed, reshaped, and reattached with ease.
2l_bottle_pvc_adapter.stl | 101.9KB |