Gene, Nowhere does it specify in the graphic that the two HAVE to be separate. The drawing is arbitrary/universal and just showing which edges are used on which steps. If you set the SEARCH_VEL reasonably high enough the machine must over travel the switch due to deceleration. Have you tried setting your search velocity high enough that the over travel is greater than your backlash compensation?
Stephen On Wed, Jan 23, 2013 at 4:11 PM, Gene Heskett <ghesk...@wdtv.com> wrote: > On Wednesday 23 January 2013 15:59:55 Bruce Klawiter did opine: > Message additions Copyright Wednesday 23 January 2013 by Gene Heskett > > > I am curious, how does LinuxCNC back off of a limit switch? > > I have a bridgeport with hand wheels so it is easy for me, just > > wondering how this is done on the big machines. > > > > Bruce > > As shown in the gfx on the wiki under homing, there is an implicit > assumption that it is a mechanical switch, with a bit of hysteresis space > between the close and the open going the other way. It's fairly well > explained, but the lack of hysteresis in an electrical contact such as I am > using, means I cannot set my backlashes for total compensations, because > the backlash takeup move may reopen the contact, and its a show stopper > error if the switch is already open when the backup move starts. I have x > home working about 90% of the time by setting backlash to half a thou in > the .ini file for x on my lathe, and around 3 thou less than real on my old > sloppy z. When x works, it does all the motions in just a few milliseconds > once the initial contact has been made. The old Z was the same except for > the 300 milliseconds the backlash moves of 20 thou take. > > > > ------------------------------------------------------------------------------ Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
