Have you checked to see what the machine has for limits/home switches? You may have all you need. If you try to use them for both - then I think you again putting the machine in a mode where you are not protected. (again - not a hobby machine :) )
(in my opinion the limit switches should be the last line of defense - hooked through the estop loop) sam On 2/12/2013 10:50 AM, Pete Matos wrote: > Okay another point I am missing, if you have your limits tied into the > estop to depower the entire system how the hell do you home the machine? > Do you have seperate home switches. I intend to use to the limits as homes > for the purposes of homing the machine. > > On Tue, Feb 12, 2013 at 11:44 AM, Pete Matos <petefro...@gmail.com> wrote: > >> Sam, >> okay now we are getting somewhere, you bring up a valid point here. I >> have been in that situation before with a runaway servo and buddy it is no >> fun. I can see what you mean about getting the drive depowered in the event >> of a runaway. I guess I was more thinking about a limit trip during a >> program run accidentally when I screwed up the program placement or >> overestimated the size of my travels ( I NEVER DO THAT REALLY!! LOL) so >> yeah I can see your point and I wonder if there is a happy medium somehow >> with a limit setup tied to the estop circuit and still being able to power >> up and jog off the damn switch so I can get back to work without major >> machine disassembly... You would think that would be kinda the way things >> are done really. I am right now talking with Machmotion about my servo >> drives and amps and should be draining my paypal account momentarily LOL... >> we shall see how that goes. Peace >> >> Pete >> >> >> >> On Tue, Feb 12, 2013 at 11:31 AM, sam sokolik <sa...@empirescreen.com>wrote: >> >>> Ok - I will say a couple more things and then shut up about it. :) >>> >>> - On conventional machines (not robot arms or such) the linuxcnc soft >>> limits are rock solid. After the machine is homed - they work 100%. >>> (again - I have never hit the limit switch when the machine was homed) >>> If you may be used to another machine control software which shall be >>> unnamed which may not be as consistent - you don't have to worry about it. >>> >>> - It really is a safety thing. what happens if the servo drive runs >>> away towards the limit switch? (encoder failure or some such failure >>> mode) Do you really want the servo drives enabled still when it hits >>> the physical limit switch? (I know I want the estop to trigger and kill >>> power) Your Cincinnati isn't a hobby machine run with small steppers. >>> You probably have tons of force that would slam into the hard limits - >>> then maybe smoke other things.. >>> >>> - You could setup a button that then allows you to enable the drives to >>> jog off the limit switches. (again - it should happen never) >>> >>> sam >>> >>> >>> >>> >>> On 2/12/2013 10:03 AM, Pete Matos wrote: >>>> Well that may work fine for you and honestly I love soft limits as much >>> as >>>> the next Guy but I honestly prefer to have the drives enabled in a limit >>>> switch trip situation so I can just backoff,backup and punt my way back >>>> into the program. It worked fine that way on my RF45. If I have my >>> way I >>>> will have both hard and soft limits working continually and the estop >>>> shutting down the show in an emergency situation. So I appreciate all >>> the >>>> ideas here but can we kinda keep the ideas pointing in that direction >>> so my >>>> already befuddled mind does not get any more befuddled than it has to >>> be. >>>> LOL thanks guys....peace >>>> >>>> Pete >>>> >>>> >>>> >>>> On Tuesday, February 12, 2013, sam sokolik <sa...@empirescreen.com> >>> wrote: >>>>> We have a brake on the y axis also. Yes it is a pain. :) I should >>>>> disable the jog until after the machine is homed. Problem fixed. :) >>>>> >>>>> sam >>>>> >>>>> On 2/12/2013 9:43 AM, Pete Matos wrote: >>>>>> That would be a real bitch to have to back off a millhead on a VMC >>> off a >>>>>> limit with a motor brake installed... >>>>>> >>>>>> Also as per the complete power down issue, having been ringside >>> when >>>> my >>>>>> Y axis drive blew and watching the bright white light coming from >>> behind >>>>>> the machine I was VERY glad the estop circuit cut all power to the >>> drives >>>>>> LOL....yeah I am good with watching the spindle coast to a stop any >>>>>> day....peace >>>>>> >>>>>> Pete >>>>>> >>>>>> On Tuesday, February 12, 2013, sam sokolik <sa...@empirescreen.com> >>>> wrote: >>>>>>> My axis limit switches are hooked directly into the estop loop. I >>> have >>>>>>> soft limits setup. The only time I have ever run into the >>> over-travel >>>>>>> limits was when I was jogging before homing (not paying attention... >>> ) >>>>>>> (and yes - I have to back off the limit manually) >>>>>>> >>>>>>> sam >>>>>>> On 2/12/2013 9:07 AM, andy pugh wrote: >>>>>>>> On 12 February 2013 14:53, Pete Matos <petefro...@gmail.com> wrote: >>>>>>>>> Thanks for the info...can you explain that last part 7i77 GPIO? >>>>>>>> The 7i77 has 32 inputs and 16 outputs for general-purpose IO. (on >>> TB7 >>>>>>>> and TB8 I think). >>>>>>>> >>>>>>>>> Did I hear you correctly when you said you wired your limits >>> and >>>>>>>>> homes in series and in with the estop circuit? >>>>>>>> No, as you say that would cause problems with backing off of a limit >>>>>> switch. >>>>>>>> In actual fact the machine I am describing doesn't yet have limit >>>>>>>> switches, it is a bit of a slow-burning project. They are likely to >>> be >>>>>>>> added fairly soon, though. >>>>>>>> However, my intention is to keep them entirely software-controlled. >>> I >>>>>>>> would be interested to hear opinions on the advisability of this. >>>>>>>> >>> ------------------------------------------------------------------------------ >>>>>>> Free Next-Gen Firewall Hardware Offer >>>>>>> Buy your Sophos next-gen firewall before the end March 2013 >>>>>>> and get the hardware for free! Learn more. >>>>>>> http://p.sf.net/sfu/sophos-d2d-feb >>>>>>> _______________________________________________ >>>>>>> Emc-users mailing list >>>>>>> Emc-users@lists.sourceforge.net >>>>>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>>>>>> >>> ------------------------------------------------------------------------------ >>>>>> Free Next-Gen Firewall Hardware Offer >>>>>> Buy your Sophos next-gen firewall before the end March 2013 >>>>>> and get the hardware for free! Learn more. >>>>>> http://p.sf.net/sfu/sophos-d2d-feb >>>>>> _______________________________________________ >>>>>> Emc-users mailing list >>>>>> Emc-users@lists.sourceforge.net >>>>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>>>>> >>>>>> >>>>> >>> ------------------------------------------------------------------------------ >>>>> Free Next-Gen Firewall Hardware Offer >>>>> Buy your Sophos next-gen firewall before the end March 2013 >>>>> and get the hardware for free! Learn more. >>>>> http://p.sf.net/sfu/sophos-d2d-feb >>>>> _______________________________________________ >>>>> Emc-users mailing list >>>>> Emc-users@lists.sourceforge.net >>>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>>>> >>> ------------------------------------------------------------------------------ >>>> Free Next-Gen Firewall Hardware Offer >>>> Buy your Sophos next-gen firewall before the end March 2013 >>>> and get the hardware for free! Learn more. >>>> http://p.sf.net/sfu/sophos-d2d-feb >>>> _______________________________________________ >>>> Emc-users mailing list >>>> Emc-users@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>>> >>>> >>> >>> >>> ------------------------------------------------------------------------------ >>> Free Next-Gen Firewall Hardware Offer >>> Buy your Sophos next-gen firewall before the end March 2013 >>> and get the hardware for free! Learn more. >>> http://p.sf.net/sfu/sophos-d2d-feb >>> _______________________________________________ >>> Emc-users mailing list >>> Emc-users@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/emc-users >>> >> > ------------------------------------------------------------------------------ > Free Next-Gen Firewall Hardware Offer > Buy your Sophos next-gen firewall before the end March 2013 > and get the hardware for free! Learn more. > http://p.sf.net/sfu/sophos-d2d-feb > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > ------------------------------------------------------------------------------ Free Next-Gen Firewall Hardware Offer Buy your Sophos next-gen firewall before the end March 2013 and get the hardware for free! Learn more. http://p.sf.net/sfu/sophos-d2d-feb _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
