Hi Scott. I have a Yaskawa V1000 on my spindle, and have installed a encoder on the spindle. Would you share what settings in the V1000 to get rigid tapping working well? I have braking resistors installed, but don't know what variable to change to bring them into play.
Any help & tips always welcome! --J. Ray Mitchell Jr. jrmitche...@gmail.com "Good enough is the enemy of excellence"author unknown On Tue, Jul 21, 2020 at 3:43 PM Scott Harwell via Emc-users < emc-users@lists.sourceforge.net> wrote: > Just got my new Control Engineering in the mail and saw this."Top 5 VFD > parameter changes explained" > > | > | > | > | | | > > | > > | > | > | | > Top 5 VFD parameter changes explained > > Chris Vavra > > Learning Objectives Setting five parameters can take care of most VFD > programming. Consider VFD control met... > | > > | > > | > > > "www.controleng.com/articles/top-5-vfd-parameter-changes-explained/" > It may help. > Scott > > On Tuesday, July 21, 2020, 12:17:05 PM CDT, Matthew Herd < > herd.m...@gmail.com> wrote: > > Hi Rob, > > Thanks for the insights. I suspected something along these lines, even if > I might have other problems with noise. I can confirm, the spindle stops > way too slowly and definitely more than 10 revolutions pass before > stopping. Long story short, I can’t readily run the machine in back gear > and the slowest I can go at 60Hz is 560 RPM without backgear. I’ll play a > bit more with how quickly I can stop the spindle with a braking resistor or > I’ll attempt to get the HAL file to engage the mechanical brake to help > transition faster. Nonetheless, 10 revolutions seems fairly ambitious > based on my best guess of how long it might take to stop the spindle even > with a braking resistor. That’s about 1 second, but should be > achievable. Currently the VFD is configured based on the fastest stop time > for max RPM, and there doesn’t seem to be a way to decrease stop time for > different inertial loads (i.e. lower gear ratios/spindle speeds). However, > I understand that the braking resistor should decrease stop time by > approximately an order of magnitude based on some reading I did yesterday. > > Thanks! > Matt > > > On Jul 21, 2020, at 1:00 PM, Robert Ellenberg <rwe...@gmail.com> wrote: > > > > Based on the videos and your descriptions of the behavior, you may be > > running into a TP issue I've seen (in simulation) with very sluggish > > spindles or very high spindle speeds. Here's what I think is going on: > > > > 1. The rigid tapping cycle allows a hard-coded 10 revolutions > > <https://github.com/LinuxCNC/linuxcnc/blob/master/src/emc/tp/tc.c#L856> > > of overtravel beyond the nominal bottom of the hole when reversing > > direction. > > 2. The spindle starts reversing direction only after the Z axis has > > reached the bottom, so the spindle has to be able to stop in 10 > revolutions > > to stay within the budgeted overtravel. > > 3. If the TP hits the end of the overtravel, it prematurely declares the > > motion to be complete and stops following the spindle motion. > > > > Do you still see this behavior if you run the spindle slower? Your > spindle > > seems to take a long time to reverse, so at high speeds you may be > hitting > > this limit. > > > > Best, > > Rob > > <https://github.com/LinuxCNC/linuxcnc/blob/master/src/emc/tp/tc.c#L856> > > > > On Tue, Jul 21, 2020 at 11:18 AM Matthew Herd <herd.m...@gmail.com> > wrote: > > > >> Ahh, so I do use limit switches and a homing routine. So it’s homing to > >> the same position (plus or minus a few thousandths or so). > >> > >>> On Jul 21, 2020, at 11:07 AM, Jon Elson <el...@pico-systems.com> > wrote: > >>> > >>> On 07/21/2020 04:20 AM, andy pugh wrote: > >>>> On Tue, 21 Jul 2020 at 10:18, andy pugh <bodge...@gmail.com> wrote: > >>>> > >>>>> We are not looking for noise, we are looking for spurious encoder > >> count resets. > >>>> But, thinking further, even if there _is_ noise on the index line, the > >>>> encoder counter should ignore it. It ignores all the _real_ indexes > >>>> unless index-enable is set true in HAL. > >>>> > >>> Yes, the only thing I can think of is he's hitting his soft limits. > Over > >> time, starting and stopping LinuxCNC, > >>> without homing, the machine limits will drift. If you have rational > >> limits in the .ini file, you will eventually reach the end of them and > have > >> really strange behavior. it can be fixed by homing in a safe position, > >>> but best to put in home switches and actually home the machine to a > >> repeatable position every time. > >>> > >>> Jon > >>> > >>> > >>> _______________________________________________ > >>> Emc-users mailing list > >>> Emc-users@lists.sourceforge.net > >>> https://lists.sourceforge.net/lists/listinfo/emc-users > >> > >> > >> > >> _______________________________________________ > >> Emc-users mailing list > >> Emc-users@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/emc-users > >> > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users