>> > > From: andy pugh: > > 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.
<<<<< SNIP <>>>> > > 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. > From: Stuart Stevenson > 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. Andy, thanks for the tip, we have now re-origined our rotary chuck at machine X0, Y0 and set AXIS to display CXYZ. Things are looking quite good. We notice two somewhat strange effects: 1. This is where we have trouble understanding Stuart's comments. With a circular cut, e.g. f100 g00 X0 Y10 g01 C360 (Cut a circle with middle of tool 10mm from chuck centre) The chuck moves at some speed (hard to measure, easy to hear - stepper) But With a larger circular cut, e.g. f100 g00 C0 X0 Y20 g01 C360 (Cut a circle with middle of tool 20mm from chuck centre) The chuck moves at a greater speed, seemingly recognising the geometry. But With a spiral cut, e.g. f100 g00 C0 X0 Y20 g01 Y10 C360 The chuck stays at a constant rotational speed throughout the spiral cut (which is performed correctly in space). Stuart, can you guide me to information regarding "CSS", I find no reference in the EMC docs ? 2. During a circular cut (as above), the AXIS display shows the machine limits box and a circle about x0 y0 which the 'tool' element travels. If we cut a 180° path and then move Y, the Y axis (in the AXIS display, not the machine) has become inverted. i.e. issuing MDI g0 Y50 moves the machine as expected, but the axis 'tool' moves towards the vewer, not away. Cutting a further 180° of course corrects this. I realise that the AXIS display has certain limitations (from my perspective it should either rotate the entire machine around the X0 Y0 axis or the cut trace should rotate - maybe this is beyond the present capabilities ?). Has anyone more experience than us (not difficult :-) ) or should we accept it as it is? It is quite usable, one must be careful. Many thanks, Robert ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity and more. Splunk takes this data and makes sense of it. Business sense. IT sense. Common sense. http://p.sf.net/sfu/splunk-d2d-oct _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
