Filament usage measuring mod

Repetier-host provides this summary for you, and not sure what the benefit of knowing this in an externally measured capacity would be ?

Also, once you've calibrated your extruder, 100mm's will be 100mm's ... so theres no need to run with a system with hardware feedback that I can think of...

Filament diameter is a different kettle of fish - and requires an entirely different sensor mechanism and feedback system and can be solved mechanically or optically...

I wouldn't mind even a manual counter to put between the spool and the printer.  I think a measure would be most useful for estimating how much left is on the spool, and would need to keep track of all extrusion and not just what is used during prints.

You of all people.... I would have thought would of cottoned on to the simplest solution to this if you really desired.... You just need to think OldSkool and look around the dumpster at work

Simply stick a  mechanical Tape Counter onto the spool itself geared against the spool holder...

But if you want an accurate measure of filament remaining, its still better to just go by weight I think, since that allows you to account for filament on spools even when they are removed from the printer... you just simply need to tare weight it receipt, tare weight an empty spool, then use the pretty accurate constant of 1.04g/cm2 for ABS and the accepted cross-section of 1.75mm filament... it'll be more than accurate enough for government work anyway lol...