me again :
... if collet is not clamping ok, then you may hear it; if missalignment is:
...... big, then you can hear this from far away
...... small, then you can hear this only of you are near the feeder; if you wish, consider to mess with the key-locks, so to be able to raise it at anytime you wish
... if torque/speed are too high, again, you may hear this : as the bar get's shorter, the 'bump' noise, should increase; by bump, i mean when the feeder advances until it hits something; in many cases, it is used to bump on the cutting insert, but there is a 'thing' about this, because, during bumping, the cutting insert, being long and thin, will flex, and :
...... this may lead to micro-damage on the insert, shortening it's lifespam
...... after flexing, the cutting insert will not come back to it's original position, unless feeder stops pushing; thus, bumping on the insert, may not be rigid; in other words, feeder torque may be high enough to flex your insert, without breaking it; this may lead to inconsistent face cut depths, which can not be detected after the part has been completed, thus this phenomen can be seen only inside the lathe; i used a dial, in order to detect how much it flexes ... somehow it works, but is not accurate
to avoid flexing ( bending ) the cuting insert, i started to bump on something more rigid, like an od turning tool shank, at the position with minimal overhang ... coding this, requires to change a bit the classical feeder-macro
feeder delivers always same torque/speed, but effect, in reality, is different, depending on bar length; as a consequence, a longer bar, that is close to 3m, will create a not so loud bump noise, while a shorter bar ( close to being dumped ) will create a louder bump noise
thus, when bumping, there is a noise that increases as the bar gets shorter ( a longer/heavier bar will require more energy to be pushed, but, as it gets shorter, it will reach higher speed )
the difference between the higher sound, and the minimal sound, is :
... lower when you bump on the cutting insert, because it flexes, thus it acts like a dumpner ( car suspension )
... higher when you bump on a tool shank, or something more rigid ...
so far, i hope it makes sense
thus, if you bump on something rigid, is easier to hear if there is too much torque/speed
if this bump is too agressive, it will make the collet lose it's grip, pushing it back, against the feeding direction ... thus the material will start to get out of the collet, just a little, at each bump, but more and more as the bar gets shorter; in the end, is possible to have the material out of the collet; is somehow similar, to when you knock a bottle of wine against a tree, so to make the bottle cap popp out
just saying, i really don't know what is happening on your machine / kindly