Wow,
Well to start most of your questions are open ended I cannot comment on what someone else is using on there machine for tooling, only that you should use what works best for you and is the realm of your machine. You cannot change the basics of your machine, cnc does not really make it faster, or able to cut better, but it does do more consistantly and typically much nice then you are able to do by hand, and of course its repeatblity is very good also.
Carbide tooling is prefered in cnc machines for several reasons, but it does have some detractors that you should know about. Carbide is almost always recomended where the cutting speeds are at least double that of HSS, and the min. cut is always greater, thats to say that you need to work it harder then a piece of HSS. Carbide has for me atleast glanced across the surface of something before it cut, I had to apply more pressure and doing so screwed up the cut I needed, it like any thing else has it place and takes some getting used to if you used HSS, of course the converse is also true.
That said, I would assume that the person doing the cutting was using a tool which was designed to do both facing and turning, there many, many, many tools, I would be the last person to ask as to which is best there are more qualified people around for that one as I prefer HSS and use it about 5 to 1. At any rate yes, the cut you saw would require the most ridgid of setups. But you should always be set up as rigid as possible for the best results. There are boring operations and threading operations that require the tool to be far away from the post, but even then only as much as you need nothing more.
As for the process, I cannot comment as I don't know what they were running, typically a item which is more advanced would be done on cad/cam before being run on a machine as the line coding would be insane(I don't have a cnc lathe so I am at loss as to the exact coding) unless its a canned cycle of some type or a combo of the above. I recomend you download the manual for Mach and read it front to back it may enlighten you to the process some. Some of the other forums maybe able to answer the software specfic and coding specfic questions, I am by no means qualifed for that. Someone else maybe able to enlighten you, also provid the link you looked at and maybe that will help us understand what you are seeing. For the most part I am a hardware/mechincal guy so I don't mess with the programing part yet as I am not finished with my cnc machine.
chris  |