On 04/11/2014 09:35 PM, Gene Heskett wrote: > I agree Jon, but I think its me that needs to learn how > more than LCNC needs to be trained. I had the capability of putting home switches on my machine from the VERY beginning, but I was lazy, didn't quite know how it was supposed to work, etc. etc.
I now KNOW I should have done it right after I moved to the original EMC! It has saved me a fair amount of trouble by eliminating all those cases where the placement of the part would have run me out of travel in some direction. Now, when I LOAD the part program, I get a message about the limit that WOULD be exceeded if I HAD run the program. > I seem to have stirred up a tempest that has escaped the > teapot, and I am almost sorry I did, but the discussion > that has followed has also been quite educational. Most > obvious is that I have some concepts about homing and > limits that I need to unlearn & learn better. Yes, there are TWO coordinate systems. One is the machine's coordinates, and the axis travel limits are in that system, referenced to the machine home position. Then, there is the work coordinate system. These systems are linked together with some offset when you do the touchoff function. You just bring the tool down to within an umpteenth, like a thickness of paper and then hit touchoff and enter .005 or whatever the thickness of the paper is. if you have a QC toolpost, you can enter all the offsets between your standard tools, and then when you touchoff one tool to the work, all the other tools are aligned to the workpiece ALSO, through the tool offsets. When you shutdown LinuxCNC, all these settings are saved, and when you home the machine tomorrow, everything is brought back in. This would be especially helpful in the lathe's X axis, you'd never have to mike a diameter again. On the mill, I don't use the tool table much, as many things need drill bits held in Jacobs chucks, so the tool length will never be the same. I could enter lengths for various end mills in end mill holders, as their length is repeatable. But, since I don't have an auto tool changer, my work procedure is to mount a tool, fixture up the first part, and do all workpieces on that tool, then mount second tool, touch off, and run all the workpieces with the 2nd tool, and repeat. Usually you can swap the workpieces very quickly, even faster than swapping tools. On a lathe, however, swapping the workpieces may have problems with repeatable position in the chuck, so you want to do all the operations on each piece before removing it. Jon ------------------------------------------------------------------------------ Put Bad Developers to Shame Dominate Development with Jenkins Continuous Integration Continuously Automate Build, Test & Deployment Start a new project now. Try Jenkins in the cloud. http://p.sf.net/sfu/13600_Cloudbees _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
