Jeff Epler wrote: > On Fri, May 04, 2007 at 11:49:22PM -0500, Jon Elson wrote: > >>Has anyone set up tandem axes in EMC2? Getting two servo axes >>to run in parallel isn't too hard to do in hal, although what >>you do with two following errors is something to consider. > > > There is a tracker item for this feature request: > http://sourceforge.net/tracker/index.php?func=detail&aid=1075625&group_id=6744&atid=356744 > > I don't think anyone is sure of all the things that need to be done > before a gantry/tandem machine will work well under emc. > > You mention having two following errors, but I think that's solved by > gantrykins (because each joint has its own following error)--however, > feedback position is still a problem (which joint position do you use > for the cartesian actual position?). This is the least of the problems. You could just route one of the signals, they should both be very close, and it is mostly for screen display only. (You'd have to have two separate PID loops running, and the parameterd for that come from the INI file. If things are tuned well enough, then maybe the identical params would be used on both, so maybe that's no issue, either.) (Also, gantrykins isn't a part of > emc yet, not even in the cvs version--there's just the code from > axis.unpy.net) > > Since the homing code I suggest hasn't been implemented yet, it's > unknown whether it will actually be good enough homing for a gantry > machine. > > There are the GUI problems for 4-axis, 3-joint machines. > Most commercial controls hide this from the operator, you only have one axis name to command, and one axis position displayed. > And then there are the problems we haven't even considered yet... what > is really needed is a developer with such a machine and the desire to > make it work. Yes, that's true.
Jon ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
