Quote Originally Posted by Tweaky View Post
Thanks Gents,
It will be a while before I can comment on much of this, but….

Irving (Hi ), said you would not use a boring tool on a CNC, why not?
Well I've not got my mill CNC'd yet, but done a lot of boring (badly - my problems are getting the centre accurate after drilling because I need to move the mill head and not rushing it so as to end up on the diameter I want and not just over! - I've learnt that you need to take roughly the same amount off each time to allow you to estimate/compensate for the movement of the bar). The point about a boring bar is that you have to adjust it and creep up on the final diameter, so the CNCability of it is limited to just driving the vertical movement (ignoring the intial XY placement). When I said 'not on a CNC machine' I meant 'not under full automated XYZ control'. Of course you could use the z-jog or a bit of g-code to get a constant Z feed to a fixed depth and that would ease things a bit. I dont know why a milled bore would not be round assuming the final cuts were done light enough not to bend the tool/quill..