Re: Oiling the ER collet nut?
hy gimpo the advice with oiling is ok, effect is less twist, but is a rare practice, as most don't use it
try instead a bearing nut, so to avoid twist entirely, thus one less variable
then clamp/unclamp the same shank a coupe of times, and check tir in front and far away from the collet; it does not matter if you will find small tir or big tir, but consistency : thus all small, or all big, but all within 0.005-0.010 for example; if you can not reach consistency, then try to repeat, by always having the collet inside the chuck at same phase/angle, and the nut to always clamp at same phase/angle; you can use a marker to draw a line, then try to re-aling this line each time you clamp/unclamp
if consistency is not found, then you'll have to check the chuck and the collet; sometimes they are both ok, while the nut may be the problem
collets with best repetition, are those with less groves, for H7/h7 play, that stick as close to the chuck as possible
may be enough to use the o4 collet for a o3.9 shank, in order to ruin that collet
All was going fine (0.004-0.005 mm of runout) until... I picked the ER20 collet for 4mm dia tools.
Bang!
you said it - bang
I carefully cleaned with alchol all of my ER-collets
if not used for long term, even if you clean them with alcohol, etc, keep them oiled, covered/wraped / kindly
ps : in picture 1559s, is needed also a check on chuck face, and to have the guarantee that face and id are true each one in respect to the other; even if your dial shows no movement, still does not mean that chuck is ok ... obviosly, is better than seeing tir, but if you try to reach that extra-precision, then ... you got it, right ?
Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg