here is the video on how to adjust fixed clamps. enjoy. [video=youtube;X-ck2YCJ9RA]http://www.youtube.com/watch?v=X-ck2YCJ9RA[/video]
As loose as possible while preventing slippage. This is as stern a test as a clamp will face - if it holds on a direct pull, it'll hold while doing a racket (you lose a bit of tension from grommet friction). This was the way I used to do it when I first started, but you get accustomed to the "feel" of how the clamps close after a while.
Kwun's video made me realize that I have been lazy on my fixed clamp adjustments and have probably been crushing strings too often, especially when I switch to strings thicker than Zymax 62. I also think Mark's advice of "loose as possible while preventing slippage" is the right way to think about this. Of course, one must not get too carried away with that approach as pushing the edge too closely on looseness could result in an accidental complete tension release right in the middle of a stringing job. As always Kwun continues to produce great quality videos with high resolution and professional lighting. Wish all Kwun's videos had been around when I first learned to string!