On Fri, 27 Mar 2009 21:52:45 -0500, you wrote: >> I'm trying to get my head around how to make AXIS and EMC behave like >> I'm used to with Mach Turn before trying it for real. >> >> >Without homing, the soft limits have no way to line up to the actual >machine position.
Hi Jon Softlimits? I don't use them. I have limit switches, I don't use them either, I think since the eighties I've hit them twice. They are simply there to stop the machine ramming the end of the ballscrews ;) I don't directly use "machine coordinates" either, they are meaningless to me as an operator. I, and many others, are only interested in work coordinates. What the Controller thinks they are is irrelevant to me, as long as I've told it where the work zero's are that should be sufficient. All I want is to simply tell it where X0 Y0 Z0 are in relation to mill stock, and in turn, the Z0 and X position (work diameter) with tool1 touching the stock (that also should tell it where X0 is). In both turn and mill that should be sufficient to run a job as long as tool 1 has NO offsets in the table. >> I do a lot of CNC turning and like many others I know, I don't use the >> home switches. They are unnecessary. I don't use them during tool >> changes I do my tool changing just far enough off the end of the stock >> so the longest tool doesn't hit the stock, really a waste of time to >> travel any further ;) >> >> >You don't have to go to the home position to change tools. You can set >the tool change position to be anything you want, >but the machine needs to be homed once when you start EMC, so that that >position can be repeated every time you start it up. Why? - I don't want it to go there when I start, I just want it to stay where it is on start up, then I can jog to the stock so I can simply tell it what the current work coordinates are. Toolchange position is defined in my code, just far enough to clear the stock, or allow me remove an replace a tool on the mill. I never tell my machines to go "home", I may tell them to go to "Zero", after I've set them. I also jog and change a zero or work coordinate during a pause (feedhold) if I find I'm out of alignment slightly or to account for tool wear. On the mill I always jog and re zero Z during the pause on tool changes, it has collets and the tool length in not always repeatable. "Home" is irrelevant unless you have home switches, or a fixed safe position, many don't. Softlimits are less useful on lathes, Z limits change dependant on where the tailstock is, and whether you are using collets or a chuck. Steve Blackmore -- ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
