Hello, I have upgraded my 3-axis cartesian machine with a 4th rotatory axis, which looks along the X-axis. In my g-code programs I want to use X, Y and Z for the position of the tool's tip on the workpiece and A for the angle between the z-axis and the axis of the tool - which is always in the yz-plane.
Therefore I have written a kinematics module, but it seems that I have problems with the tool length compensation. Now I have the following questions: In kinematicsForward and kinematicsInverse: What is the point EmcPose 'world' exactly? Is it the absolute pose of the tool tip (like specified in the g-code program) or is the tool length compensation already applied by the interpreter? - In principle this could be possible since A, (B and C) are known. Tool offsets could be specified in the tool's coordinate system then. Then pose 'world' would be the mount point of the tool in my case. This second option would be beneficial, because then no kinematics module has to deal with tool length compensation. Or do I have to handle the tool length compensation by myself in the kinematics via a HAL input pin which gets the tool length information from motion.tool_offset_z or w? Before I had the 4th axis, I used trivkins, and it does not contain any tool length compensation related code, but tool length compensation already worked out of the box. So probably it is already applied by the interpreter. But in the source code I have only found that the tool_offset is added / subtracted to / from other poses. With a trivial kinematic this is sufficient, but my tool's axis is not along x-, y- or the z-axis - it is [0, -sin(A), cos(A)]. Does it matter which entry of the tool table (Z or W) I use for tool length compensation? Maybe I have simply overlooked something. The rest of my kinematics module works in principle (qualitative movement is OK, it seems to be just off by the tool's length). One other thing: Does the AXIS user interface support displaying the orientation of the tool. It seems that it always looks along the z-axis, regardless of A. I am using LinuxCNC 2.5.1. By the way thanks for this great software. Thank you in advance for your answers, Martin ------------------------------------------------------------------------------ Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
