DIY CNC Router from old printer/scanner parts

[Frank S]

Maybe I am looking at this from left field or am not understanding something.
but when you mentioned coils of tubing rolled out and cut to a set length it started me to thinking along the lines of a mig welder wire feed style with smooth rollers having a radius grove to match the tubing. the tubing would be fed through a sleeve the rollers would feed it through an output sleeve with a slot in it that would allow a meat cutter type circular blade to slice off the tubing the length would be set by a micro-switch stop that controlled every thing when the tube hit the switch the switch would stop the feed and start the saw blade which would slice off the part and retract a second micro switch would activate the dormeyer solenoid to lift the saw out of the way start the feed and trigger another dormeyer solenoid to retract the length stop switch plate just for an instant which would fall back in place as the cut piece of tubing advanced and fell away starting the process all over again
Again I am probably looking at this from under the pyramid and don't see the scope of things