Some users of my adjustable vang (See SeaWind Express issue #7, Mark II version) have experienced pull out of the threaded rod or screw from the plastic rod ends. We find that the hole in the rod ends is variable in diameter so that some screws fit snuggly while others are loose. Filling the holes with epoxy was recommended but we find that the epoxy does not adhere strongly enough to the plastic and can still pull out. If you have this problem it can be fixed with a dab of CA glue in the hole and pushing the rod back in quickly.
A better solution for those contemplating building a new vang is to use metric fittings. Threaded 2.5 mm stainless steel rod can be purchsed from Small Parts Inc (Part # TRMX-25-25). The remaining 2.5 mm parts can be ordered from Tower Hobbies:
Tap & Drill set LXE219, socket cap screws LXE018, hex nuts LXE053 and of course the same filling station can pick up GPMP4156 for the barrel. I have made two of these and everything fits snuggly and will be quite rugged. Mike