Gentlemen, With the R in the G02/G03 program code the control calculates the center point. When the start point and the end point approach one another any inaccuracy in either the start point or the end point will cause the center point calculation to deviate from the desired center point to the extent the resulting center point location may be out of print tolerance. You will have the radius accurate as you desire but the location of the radius may not be where you desire. Designating the center point location with the IJK register values will result in the desired radius center point location. You may be required to adjust the start position or end position so the control will happily run your code. It is likely you would never see the extreme out of tolerance location but forewarned is forearmed. thanks Stuart
On Tue, Jan 15, 2019 at 1:06 PM John Figie <[email protected]> wrote: > I Also want to add that John Elson seems to be saying the opposite of the > LinuxCNC gcode reference. Was that a mistake? Am I missing something? > > http://linuxcnc.org/docs/html/gcode/g-code.html#gcode:g2-g3 > > "It is not good practice to program radius format arcs that are nearly full > circles or nearly semicircles because a small change in the location of the > end point will produce a much larger change in the location of the center > of the circle (and, hence, the middle of the arc). The magnification effect > is large enough that rounding error in a number can produce > out-of-tolerance cuts. For instance, a 1% displacement ....." > > Sincerely, > > John Figie > > On Tue, Jan 15, 2019, 6:39 AM John Figie <[email protected] wrote: > > > Fusion 360 has a post processor setting to use radius arcs instead of i j > > k. Radius arcs is not the default for linuxcnc post. I have been using > > Fusion with the default i j k arcs and have had no issues so far. > > > > > > John Figie > > > > On Mon, Jan 14, 2019, 11:36 AM Jon Elson <[email protected] wrote: > > > >> On 01/14/2019 10:53 AM, [email protected] wrote: > >> > Is adding a #TOLERANCE_INCH and #TOLERANCE_MM to the .ini file > >> > sufficient? > >> > What tolerances are reasonable? > >> > > >> > > >> It depends on how many decimal places your CAM package > >> supplies. If it supplies 4 digits > >> (X1.2345) then probably .0002 should cover all the roundoff > >> errors. > >> > >> Jon > >> > >> > >> _______________________________________________ > >> Emc-users mailing list > >> [email protected] > >> https://lists.sourceforge.net/lists/listinfo/emc-users > >> > > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Addressee is the intended audience. If you are not the addressee then my consent is not given for you to read this email furthermore it is my wish you would close this without saving or reading, and cease and desist from saving or opening my private correspondence. Thank you for honoring my wish. _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
