>snippet of program code that checks every declared axis not so marked. the homing exemption is included in the trajectory planner initialization and is either true or not true as far as i can tell - nothing about some joints having homes and others not. the problem is that the diabolical homing mechanism starts at zero, but does not end if there is a vacant element of the sequence. the fix i found to work is the home is not mandatory at all, but what i really want is home is not mandatory for joints without a well defined home position. for instance, there is no c axis (spindle) declared, but spindle homing is not required.
as for stepper driving, do you know if the direction signal is continuous from period to period of the base cycle of the parport controller? i'm thinking i should put a scope on the dir signal line to see. the dirsetup and dirhold values in the hal ini are huge compared to the steplen and stepspace. what's in nS and what's in base periods? the conf wizard doesnt inform. and i seem to recall reading about tuning where both steplen/space and dirsetup/hold were set as base period multiples in the example. http://wiki.linuxcnc.org/emcinfo.pl?TweakingSoftwareStepGeneration, section 1.4. so the units used for step and dir in the hal ini are not jiving well. ~ , 8/9/11, Kent A. Reed <knbr...@erols.com> wrote: From: Kent A. Reed <knbr...@erols.com> Subject: Re: [Emc-users] dedication To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> Date: Tuesday, August 9, 2011, 4:58 AM On 8/9/2011 6:13 AM, charles green wrote: > no, axis3 does not home. it is a rotary axis and from experience, i decided > that a home switch was not needed for the moment. the no_force_home=1 line > in the .ini file trajectory section fixes the problem, but it was not > intuitive that an axis not included in a homing sequence would be required to > home anyway. the config files are identical to the stepper configuration > wizard's output. the first try was to comment out the home position and > offset lines for that axis, but that had no effect. > > anyway, that problem solved by no force home. the three linear axes still > home correctly. the next hurdle is to figure out the relationship between > the steplen, stepspace, dirhold, and dirsetup. they have vastly different > values in the hal.ini, and from watching the motors move, it looks like the > direction signal is not always properly applied - the z motor intermittently > goes the wrong direction during a g1 move. un fortunately, i'm stuck for the > time being with a tb6560 based stepper driver board, which i've since read is > something to be avoided. > > ~getting what i paid for/could afford > > Charles: I'm very glad you found the solution. The key lies in your phrase "it was not intuitive that an axis not included in a homing sequence would be required to home anyway." The way one tells EMC2 not to include an axis is to use the NO_FORCE_HOME flag (not being intuitive, computers have to be told). The error message you quoted to me yesterday arises from a snippet of program code that checks every declared axis not so marked. In the User Manual, 3.3 Homing, it says "After starting EMC2 each axis must be homed prior to running a program or running a MDI commands." It goes on to say one uses NO_FORCE_HOMING to change the default behavior. How would you suggest we could clarify the documentation? As for your stepper driving issues, every CNC controller, not just EMC2, needs to be tuned and unfortunately it's a tedious process. Fortunately, there are folks here with lots of experience. Ask questions. That's what the emc2-users list is for. Regards, Kent ------------------------------------------------------------------------------ uberSVN's rich system and user administration capabilities and model configuration take the hassle out of deploying and managing Subversion and the tools developers use with it. Learn more about uberSVN and get a free download at: http://p.sf.net/sfu/wandisco-dev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ uberSVN's rich system and user administration capabilities and model configuration take the hassle out of deploying and managing Subversion and the tools developers use with it. Learn more about uberSVN and get a free download at: http://p.sf.net/sfu/wandisco-dev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
