Thank you very much for the detailed answer. One thing you must know, is that homing is not configured (yet) on my machine. I only recently installed a few limit switches, so I could use that, along with the index pulse of my encoder and re-home (real homing, not software reset to zero homing).
But I've yet to install limit switched to all axes, so the behavior I'm looking for is, when I click "home axis" in Axis, I'd want the DRO to stay where its at (since POSITION_FILE reload the right position). On Mon, May 27, 2019 at 8:13 PM andy pugh <[email protected]> wrote: > On Mon, 27 May 2019 at 20:15, Maxime Lemonnier <[email protected] > > > wrote: > > > > > When I reload linuxcnc, and want to use the MDI, I have to home all axis > > But then I'd loose the current position (reset to zero). > > > The machine moves to the home position, but your G554 (etc) offsets stay > the same. > So you should be able to stop mid job, turn off the machine, restart, > re-home and all the work coordinate systems should be in exactly the same > place. > (This is the case even without the POSITION_FILE.) > > > > Now you're thinking : use > > the 'NO_FORCE_HOMING = 1' option. But if I do I loose the ability to use > > the > > soft limits, which I need. > > > > Have you tested this? My impression is that this all should work, though > you might _also_ need to exclude your axes from the homing sequence. > > > > (homing sequence or moving the machine back to 0 and etc is not an > option, > > because of the precision (0.1deg backlash) of my roatry axes) > > I just don't want the machine to accumulate error after multiple reboot. > > > The error shouldn't accumulate. It should, at worst never be more than the > backlash. > > In fact you are more likely to accumulate errors by not homing. > > As you have servos, can you swap to absolute encoders? That ought to be a > complete solution. > > (And, as an exotic option, my lathe uses a combination of POSITUOIN_FILE > and the single-turn absolute nature of resolvers to be absolute without a > homing move. Most of the time. I do sometimes have to re-home, I have not > quite figured out why yet. I think part of the reason is that I have two > complete versions of LinuxCNC on that machine and only one has the updated > resolver code) > > -- > atp > "A motorcycle is a bicycle with a pandemonium attachment and is designed > for the especial use of mechanical geniuses, daredevils and lunatics." > — George Fitch, Atlanta Constitution Newspaper, 1916 > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
