On Sun, 30 Aug 2009 12:56:14 +0100, you wrote: >Can somebody explain G76 please. > >I don't understand the implementation method, in particular the "drive >line" mentioned in the manual. > >The docs say the sample program g76.ngc shows the method. > >The figures in that don't make sense for a 1/4x20 thread. The initial >position is z.2 z.2
Oops, should read z.2 x.2 >The major diameter of that thread is .2449 ?? > >Manual says the "drive line" is a safe position outside the thread and >also goes from the initial location to the value specified in the Z- >value. If so how can that cut an external 1/4x20 thread? (I'm guessing >the drive line is the thread major diameter + some arbitrary value set >by the op, and is the same as the clearance distance) > >Was that program written for radius mode? > >Wouldn't a XZ start point and an XZ end point and a return clearance >distance have been more practical? > >It would appear from the parameters that the G76 doesn't support taper >threads - defining the start/end positions make that possible. Additionally - difficult to tell what's going on, lathe is set up in mm, when running a G20 file, DRO's and feed still display in metric units :( Steve Blackmore -- ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
