It is a little like a screwless vise, isnít it? Those look handy but itís hard to choose just one vise! There seems to be an endless variety of ones that have already been made.
In this case it was a little easier deciding what features I wanted.
My two other machine vises need stuff to be pretty close to flat and parallel in order to grip it securely. A lot of the time itís easy just to shim them but their small size often prevents using much extra between their jaws. Their size makes up for their limited mounting options, though.
This one allows some different approaches, like you pointed out including how to tighten it, which is important on my small Atlas mill with a one-slot table. At the time I made it it was only capable of taking reasonable cuts using the horizontal spindle which meant setup could be very awkward, so I tried to work out a combination of solutions for things that were tricky to do other ways.