On Sat, Oct 06, 2007 at 09:55:21AM -0500, Stuart Stevenson wrote: > I need to implement 5 axis tool length compensation. The > calculation is simple. Would the implementation be better in EMC or > HAL?
Tool length compensation is currently in the canon level, which is between the interpreter and the rest of EMC proper. There are currently X and Z offsets and these are simply added to the number the interpreter asks for when it parses a line of gcode. For example if the interpreter wants a traverse to Z=1 and the Z tool offset is 1, the canon level translates this to Z=2 and sends it on to the rest of EMC. Adding length compensation in this style for the rest of the axes is not too hard, only tedious. It touches many levels of the code from the tool table (whose format would have to change again) through the guis (some of which show these values when you load a tool). However the big question in my mind is whether this is what 5 axis tool length compensation even means. Is it this straightforward? In a 3 axis mill or a 2 axis lathe, the compensated axes are independent/orthogonal so it's easy to see how to offset them (you only do the addition I described above.) Is it like this for the general 5 axis case? Is there even a general 5 axis case since 5 axis machines come in so many configurations? I don't have an understanding of how, in general, a 5 axis machine is controlled/programmed at the gcode level. You've told me before that short G1 moves are used in inverse time mode, which makes me think the control really doesn't have to know much about the machine; that specific knowledge about its configuration is left to the programmer and/or CAM. How does length compensation fit into this picture? Chris ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
