On Tue, Nov 06, 2012 at 07:31:07AM -0600, Stuart Stevenson wrote: > > Best: (heh - my opinion) :) > The IJK values from the start point to the radius center point would also > allow calculation of the normal vector. > Using the IJK (ie: G02(3) X Y Z I J K) to determine the 3D space location > of the center point would then determine the normal vector for > interpolation motion. Calculating the normal vector using the one added > value on the line would require the least programming changes.
I don't understand what you mean. Can you elaborate in mathspeak? I think andy thinks you mean calculate normal as (XYZ - current) cross (IJK - current) which he rightfully says flips direction given an arc of more or less than semicircle, and for semicircle and full circle it's indeterminate. Also the "third" (normal to selected plane) component in XYZ is currently used to give a helical offset, and that will mess up your normal with the above scheme. Can you give a more detailed spec that handles helixes, semicircles, and full circles? Perhaps even make a wiki page we can all work on? As you probably know, arbitrary nonplanar helixes are already supported in the trajectory planner and other layers past the interpreter and canon. It's the gcode that makes it tricky. In fact, interested folks might want to check out http://git.linuxcnc.org/gitweb?p=linuxcnc.git;a=shortlog;h=refs/heads/arbitrary-arc ------------------------------------------------------------------------------ LogMeIn Central: Instant, anywhere, Remote PC access and management. Stay in control, update software, and manage PCs from one command center Diagnose problems and improve visibility into emerging IT issues Automate, monitor and manage. Do more in less time with Central http://p.sf.net/sfu/logmein12331_d2d _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
