i became annoyed with clamping small diameter tubes in the vise, and fumbling around with my janky v-block made from 2x4 scraps. knowing that i would have to hand finish (de-burr and chamfer edges) a bunch of bronze bearings and their respective journals-- that was the final push to motivate me to make a new clamping block. here 'tis:
it has a lip to keep it from dropping out of the vise, im going to spring load it so it opens and stays in the vise as i open the jaws.
the 3 V's will accommodate sizes from 1/8 to 1/2".