On Fri, Oct 7, 2011 at 4:12 AM, andy pugh <bodge...@gmail.com> wrote:
> On 7 October 2011 08:17, Robert von Knobloch <b...@engelking.de> wrote: > > From: andy pugh: > > > >> I think for a C axis it would make sense to use the XY origin of the > >> current coordinate system. > > > > This is not possible, as the origin of X & Y is one corner of the bed. > > (no room to bolt the chuck here). > > Sorry, I was meaning that EMC2 should perhaps be using the current > coordinate system, not that you should be using the machine coordinate > system. > > However, it would be possible to reconfigure the axis limits in the > INI file to move machine origin to a point on the table so that the C > axis could be at machine X=0, Y=0. It is just a matter of changing > numbers in the INI file. keeping the axis range the same, but > symmetrical about zero. You could then G53 X0Y0, align the chuck to > the spindle, and then the preview would be correct. > > > It's not so much about the view, but how the machine calculates cutting > > speed. > > It is probably best to use inverse time mode for cuts that combine > rotary and linear movements. I don't think that the cutting speed > calculations take rotary axes into consideration even if the rotary is > aligned to machine origin. > http://www.linuxcnc.org/docview/html/gcode_main.html#sub:G93,-G94:-Set > In G53 mode you tell EMC2 how long each cut should take, not how fast to > move. > G53 s/b G93 The programmer/programming system calculates the appropriate value for the feed rate command to cause the cutter to move at the programmers desired feed rate/chip load. EMC2 has no knowledge of where on the rotary axis the cut is taking place unless you are using CSS (constant surface speed). To use CSS you need to instruct the control where the cut is taking place. > -- > atp > "Torque wrenches are for the obedience of fools and the guidance of wise > men" > > > ------------------------------------------------------------------------------ > All of the data generated in your IT infrastructure is seriously valuable. > Why? It contains a definitive record of application performance, security > threats, fraudulent activity, and more. Splunk takes this data and makes > sense of it. IT sense. And common sense. > http://p.sf.net/sfu/splunk-d2dcopy2 > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- dos centavos ------------------------------------------------------------------------------ All of the data generated in your IT infrastructure is seriously valuable. Why? It contains a definitive record of application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-d2dcopy2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
