On Friday 11 April 2014 22:21:53 Jon Elson did opine: > On 04/11/2014 01:35 PM, John Kasunich wrote: > > I'm pretty sure that Gene doesn't "touch off" in the way > > we think of it. If I've followed past conversations correctly, > > he actually homes the machine using contact between > > tool and work (or tool and a widget that gives him a > > reference point). > > > > Normally, you'd home the machine once and be done > > with it, and the limits would be set to protect the machine > > while allowing you to get your work done. Then use > > "touch off" and G5x coordinate systems and/or tool > > offsets to deal with tool and part specifics. > > > > Since Gene uses home to deal with tool and part specifics, > > he has the side effect of limits moving around. > > Well, that is wrong, and explains the results. The homing > system > and having both machine coordinate and work coordinate > systems makes MUCH sense, and has been common practice > on machines for a LONG time. If Gene wants to keep doing things > that way, he should just set the machine limits to +1000 and > -1000 > and not use it. But, the machine limits can save a lot of > trouble, > as when it detects an overtravel when the part program is > LOADED, > way before you even hit run! On the lathe, it gets more > complicated, > as the tools have offsets in several axes, and you have to watch > out for chuck jaws and such. I don't have a CNC lathe yet, so > I am only slightly familiar with the problem, but I think > LinuxCNC > doesn't handle interference with tools (yet) as the problem gets > a bit messy. > > Jon
I agree Jon, but I think its me that needs to learn how more than LCNC needs to be trained. 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. Some, if not all, of this "ways & means to do it" really does need to find its way into the integrators manual so that hopefully the next hobbyist like me, who has had his hands on the dials, lathes in particular, for about 65 years without ever learning the underlying "good practices", can be steered in the right direction and not paint themselves into a corner learning bad habits. Granted, this is the stuff one would get beat into his head if he ever took a machining class at a VOC-ED facility, but its obviously stuff that it doesn't hurt to repeat in the local vernacular. So I now return you to your regularly scheduled release wrangling. :) 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
