OK, I see that you mean now. As they say, a picture is worth a thousand words. (Though that does not seem to hold true when writing an essay for English class!?)
I still think naive cam detector is doing exactly what it is suposed to. If the maximum deviation of an arc from a strait line is within Q they are collapsed into a single linear move, which is exactly what I see in your screen dump. Kurt On Thu, Feb 16, 2017 at 2:53 PM, Todd Zuercher <[email protected]> wrote: > I didn't expect the Naive cam detection to do this. > https://s2.postimg.org/ezy3wjfjt/bug.png > Maybe I am reading the docs wrong. > > ----- Original Message ----- > From: "Kurt Jacobson" <[email protected]> > To: "Enhanced Machine Controller (EMC)" <[email protected]> > Sent: Thursday, February 16, 2017 2:10:26 PM > Subject: Re: [Emc-users] G41-42 and G64 Bug? > > I don't really know any thing about this, but I'd say that is the expected > behavior based on the description of G64 Path Blending: > > "On G2/G3 moves in the G17 (XY) plane when the maximum deviation of an arc > from a straight line is less than the G64 P- tolerance the arc is broken > into two lines (from start of arc to midpoint, and from midpoint to end). > those lines are then subject to the naive cam algorithm for lines.[1]" > > It sounds like your Q value is larger than the radius of your compensation > lead out, so the arc is broken up into two line segments. Since these line > segments are within Q of a linear move they are collapsed into one linear > move, and since this linear move is within Q of the original linear move > the whole path is collapsed in to a single linear move which is treated > essentially becomes a long compensation lead out move. > > Just thinking out loud here, again, I am a complete noob so take this with > half a grain of salt. > > [1] http://linuxcnc.org/docs/html/gcode/g-code.html#gcode:g61-g61.1 > > Kurt > > On Thu, Feb 16, 2017 at 1:32 PM, Todd Zuercher <[email protected]> > wrote: > > > I was playing arround with G41 and G42 in a simulation and I think I > might > > have found a bug with the Naive CAM Detection. > > The shape I was simulating was a semi circle with the start/end point on > > the flat side and a single G2 arc move connecting the end points. > > The simulation behaves strangely. With a tool radius of .125" and .25" > and > > staight G64 the tool path precisely followed the path (white and red > lines > > over lapped). With G64P0.001, the same. The expected behavior is cutting > a > > straight line parallel to the programed line offset the tool radius, cut > an > > arc around that end point to connect to the offset path of the commanded > > arc cut. all good right. > > With G64P0.001Q0.2 there is odd behavior. It moves in a straight line > from > > the beginning of the compensated straight line cut to the begining of the > > compensated arc cut completely ignoring the compensated end point of the > > straight cut. I know having such a large Q setting is a little odd. I > also > > see simular behavior with G64P0.2 (no Q specified, same as Q0.2) only > with > > more rounded corners. > > I seem to see the odd behavior when ever Q is about 2/3 or more than the > > tool diameter. > > > > -- > > > > ======================================== > > > > Todd Zuercher > > mailto:[email protected] > > > > ======================================== > > ------------------------------------------------------------ > > ------------------ > > Check out the vibrant tech community on one of the world's most > > engaging tech sites, SlashDot.org! http://sdm.link/slashdot > > _______________________________________________ > > Emc-users mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > ------------------------------------------------------------ > ------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, SlashDot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > > ------------------------------------------------------------ > ------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, SlashDot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
