I think these have been suggested, but just to clarify (as much in my mind as anyone else's):
(a) Assuming you decide the Z height is to be 0.1 lower than it is at the moment, use MDI mode to go to a known position (say X0 Y10 Z20), Step Jog down 0.1 and Home Z to a value of 20. (b) G92 can be used, with care, and that can be set manually, so once you know how much you need to add (+ or -) you can manually enter the appropriate G92 using MDI mode. Go to X0 Y10 Z20 then, assuming you want an extra 0.1 on Z, G92 X0 Y10 Z19.9 should apply a global offset. G92.1 will cancel that offset. (c) You could alter the tool offset in the Tool Offset table. I think this can be done quickly and conveniently via File>Edit tool table, or if you issue a T~ M6 command, but it would let you enter a new value directly. Once completed, you need to invoke a G43 to have the change take effect, but that could be in the program when it runs, anyway. (d) You could use a G10 L20 command. Take the tool to a known position like X0 Y10 Z20. Assuming you want to make it X0 Y10 Z19.9 (so that you are effectively getting an extra 0.1 depth next time you run the program) then type G10 L20 X0 Y10 Z19.9 and LinuxCNC will calculate the offsets required to assign those co-ordinates to that point. That is done in MDI mode. When you run the program again, the Z will be 0.1 lower without altering the depths in the program. (e) Less handy - you might be able to leave the G54 offsets as they are, but always add a variable whose value is picked up from a memory location. The "added-on" value would be set manually, either by defining its value at the start of the program (so this would mean a quick edit to set its value), by placing it directly into the memory location using MDI mode, or by defining a button to set its value. When the program runs next time, it will pick the value up and add it on to the position. This is a bit like adding a wear offset (see http://comments.gmane.org/gmane.linux.distributions.emc.devel/6631 ) which is not currently implemented in LinuxCNC. I have not tried this. These would all require some testing and checking, as my machine is off at the moment, so I have not tried these out (although the situation is familiar enough, and I have used (a) to (d) regularly. Simplest is best, of course, so (a) is often enough for my jobs. Regards, Marcus On 18 Jan 2013, at 05:51, Chris Radek wrote: On Thu, Jan 17, 2013 at 09:37:30PM -0500, Erik Friesen wrote: > > One downside to this, is that unless your chosen variable is persistent, it > won't show up correctly in the axis preview. One workaround is to use one > of the unused persistent variables from something, or the way I did it, I > custom built linuxcnc to add some loose persistent variables. It may not be well documented, but any variable number becomes persistent if you just add it to your var file manually. ------------------------------------------------------------------------------ Master HTML5, CSS3, ASP.NET, MVC, AJAX, Knockout.js, Web API and much more. Get web development skills now with LearnDevNow - 350+ hours of step-by-step video tutorials by Microsoft MVPs and experts. SALE $99.99 this month only -- learn more at: http://p.sf.net/sfu/learnmore_122812 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Master HTML5, CSS3, ASP.NET, MVC, AJAX, Knockout.js, Web API and much more. Get web development skills now with LearnDevNow - 350+ hours of step-by-step video tutorials by Microsoft MVPs and experts. SALE $99.99 this month only -- learn more at: http://p.sf.net/sfu/learnmore_122812 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
