I have to cut hundreds of pieces of small diameter copper and ss
tubing ranging from 2mm to 7mm in diameter and about 3 to 4mm long.
I hate to have to saw cut them one at a time.
It should be possible to rig up a jig on the same principle as a
jump ring cutter-- a box (three-sided with a lid that presses the
tubes to hold them securely, perhaps) to hold multiple lengths of
same-size tubing, with a slit to allow you to run a circular cutting
blade or thin separating disc in a flexshaft, then slide the batch of
now-shorter tubes down, cut again, and so on.
I don’t have a clear image of exactly how this would be made, but if
the tubes you’re cutting are in batches of the same diameter, the
basic idea of rigging something to cut across, say, 10 at a pass
would seem to be the way to go.