On Saturday 12 April 2014 00:10:38 Jon Elson did opine: > 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.
IF you do all your boring with a bar and the post itself is never turned. Unforch, the size of pockets I need to make, like for a fresh #209 nipple, are usually predrilled 3/16", then an 1/8" two flute mill is chucked in a drill chuck attached to the boring bar holder, and the tool post turned 5 degrees CCW so one corner of the mill is used for a boring bar. Resetting the tool post dead square still means the tool table is toast. So I have not spent a huge amount of time trying to calibrate it. For that job, and similar ones, I need to learn how to make the cutter out of A2 rod and harden it. For that, I need a rotary table that runs on dead center, or to invest in a 5C setup for tool holding. My 4" rotary has no morse taper center so centering a workpiece is a major PIMA. I have the A2, but not the tempering ability. > 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 the mill, like for PCB etching, yes, I use a pallet made for that sized PCB. But again, I don't have tool holders, only collets or drill chucks. Tool tables are a waste of time, so I usually incorporate one of my probing routines to set the TLO. > 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. Absolutely. > 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 Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS ------------------------------------------------------------------------------ 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
