21:29:53 < cradek> I've been pondering G68 (coordinate system rotation) 21:30:06 < cradek> I think I could do it, if I found a full spec 21:30:17 < cradek> I don't care so much about scaling 21:30:33 < jmkasunic> hmm, could you write the quick reference entry? (that command seems like it could be hard to use) 21:30:40 < cradek> the fanuc manual someone posted leaves me with a lot of questions, but it may be the best I can find 21:30:57 < cradek> G68 X1 Y1 R45 (rotate 45 degrees around the point 1,1) 21:31:20 < cradek> or G68 R45 (rotate 45 degrees around the current point) 21:31:25 < jmkasunic> rotating and offsetting programs to match the material has been a "want" as long as I can remember 21:31:31 < cradek> yes 21:31:35 < cradek> offsets are easy of course 21:31:49 < cradek> planar rotation is not so hard 21:31:57 < cradek> arbitrary rotation is much harder 21:32:04 < jmkasunic> yeah 21:32:21 < cradek> isotropic scaling is easyish. anisotropic scaling is much harder 21:32:25 < jmkasunic> and the next step is that people would want to spec the rotation by touching off in a few different places, rather than calculating angles 21:32:39 < jmkasunic> anisotropic scaling of circles anyway 21:32:45 < cradek> that's just a matter of gcode atan[]/[] 21:32:54 < cradek> yes arcs are the real problem 21:33:22 < cradek> we should ask stuart to bring us a stack of manuals. 21:33:33 < cradek> maybe they could spare them for the week. 21:33:53 < cradek> also note that if you're rotated in XY, G18/G19 arcs are no longer planar 21:34:14 < jmkasunic> eww 21:34:35 < cradek> the fanuc manual does not say whether you can switch planes to do these arcs, or what happens if you do 21:34:35 < jmkasunic> so before you can do rotation you have to do arbitrary arcs? 21:34:39 < cradek> so maybe it's just not allowed 21:34:39 < jmkasunic> that just got a lot harder 21:34:57 < cradek> yeah I just don't know a lot of the details. 21:35:24 < jmkasunic> if you say "you can only rotate in the current plane, and as long as there is a non-zero rotation, you cannot change planes", that would simplify things a lot 21:35:30 < cradek> the fanuc manual also does not describe what happens to the other coordinate systems. (can you rotate in g54 and then switch to g55? and where is it??) 21:35:35 < jmkasunic> and satisfy many of the people who want it 21:35:49 < cradek> yes it certainly might be enough. 21:36:12 < jmkasunic> I would say (just off the cuff) that rotation commands should only affect the current coordinate system 21:36:48 < jmkasunic> in fact I might describe the command as "rotate coordinate system" 21:36:56 < cradek> I agree that seems like a reasonable thing to do 21:37:15 < jmkasunic> hmm 21:37:22 < jmkasunic> could this be an extension of G10 21:38:04 < cradek> that's a good way to think about it (although I'd rather use what seems to be the standard gcode for it) 21:38:24 < jmkasunic> thats the problem with standards, everybody has one 21:38:27 < cradek> I had not thought of the rotation "belonging" to a g5x system but that might be the ticket 21:38:52 < cradek> how it interacts with g92 is a total mystery too