[Emc-users] Steppers losing position
Hello! I have a strange situation: Stepper motor of Z axis on a cnc router is losing it's position - doing a series of numerous holes in material will end up with various depths of holes. The strange part is: 1) for each time, when machine is running, it will lose position only in one direction; if holes are getting deeper, then they only get deeper, not the other way; 2) the direction of drift will change randomly as machine is restarted and only then; simply running another g-code file will not change the direction of drift; There is Nema23 stepper motor and Gecko stepper driver. Motor cable is checked for loose contact, step/dir signal lines are checked for loose contact, ballscrew and linear rails are checked for any damage to cause extra resistance in particular direction, the clutch between motor and ballscrew is checked not to slip. I am totally out of ideas, where to look. Has anyone ever experienced anything like that? What puzzles me most is the consistency to maintain direction of drift and yet randomly change, when whole system is restarted, so any suggestions will be appreciated. Viesturs -- Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Steppers losing position
If the holes are deeper doesn't it means that the motor is making more steps and not less ? Is it possible that you have extra steps due to noises or bad connections PC --- BoB --- Gecko Drive ? Alex On Thu, Sep 4, 2014 at 5:07 PM, Viesturs Lācis viesturs.la...@gmail.com wrote: Hello! I have a strange situation: Stepper motor of Z axis on a cnc router is losing it's position - doing a series of numerous holes in material will end up with various depths of holes. The strange part is: 1) for each time, when machine is running, it will lose position only in one direction; if holes are getting deeper, then they only get deeper, not the other way; 2) the direction of drift will change randomly as machine is restarted and only then; simply running another g-code file will not change the direction of drift; There is Nema23 stepper motor and Gecko stepper driver. Motor cable is checked for loose contact, step/dir signal lines are checked for loose contact, ballscrew and linear rails are checked for any damage to cause extra resistance in particular direction, the clutch between motor and ballscrew is checked not to slip. I am totally out of ideas, where to look. Has anyone ever experienced anything like that? What puzzles me most is the consistency to maintain direction of drift and yet randomly change, when whole system is restarted, so any suggestions will be appreciated. Viesturs -- Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Steppers losing position
On Thursday 04 September 2014 11:07:07 Viesturs Lācis did opine And Gene did reply: Hello! I have a strange situation: Stepper motor of Z axis on a cnc router is losing it's position - doing a series of numerous holes in material will end up with various depths of holes. The strange part is: 1) for each time, when machine is running, it will lose position only in one direction; if holes are getting deeper, then they only get deeper, not the other way; 2) the direction of drift will change randomly as machine is restarted and only then; simply running another g-code file will not change the direction of drift; There is Nema23 stepper motor and Gecko stepper driver. Motor cable is checked for loose contact, step/dir signal lines are checked for loose contact, ballscrew and linear rails are checked for any damage to cause extra resistance in particular direction, the clutch between motor and ballscrew is checked not to slip. I am totally out of ideas, where to look. Has anyone ever experienced anything like that? What puzzles me most is the consistency to maintain direction of drift and yet randomly change, when whole system is restarted, so any suggestions will be appreciated. Viesturs Can we assume you have lengthened the dirsetup and dirhold settings? I don't have any gecko's, but this sure seems to be an ongoing problem with them. From previous messages, it seems a trip to gecko for repairs fixes it, but a random direction fixed at machine boot? Thats weird, and I've no clue. Cheers, Gene Heskett -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Genes Web page http://geneslinuxbox.net:6309/gene US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS -- Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Steppers losing position
2014-09-04 18:16 GMT+03:00 alex chiosso achio...@gmail.com: If the holes are deeper doesn't it means that the motor is making more steps and not less ? Is it possible that you have extra steps due to noises or bad connections PC --- BoB --- Gecko Drive ? Yes, as I said, motor is drifting in particular direction, which may change (not always), if system is restarted, but the direction of drift does not change, once the system is running - if it gradually goes up, then it does so; if down, then it keeps getting deeper. There is no BoB, step/dir signals go directly from 5i23 to Gecko. Viesturs -- Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Steppers losing position
As Gene is suggesting , here http://linuxcnc.org/index.php/english/forum/16-stepconf-wizard/27293-solved-tuning-stepper-motor-with-gecko-201-driver?start=10 is a discussion on the forum regarding problems with steps and Gecko Drive . A question for you ... the router is brand new (I mean that you have finished the setup) or is a already working machine ? This question is to understand if the machine was working fine before and later start with the problem you are mentioning. Alex On Thu, Sep 4, 2014 at 5:21 PM, Gene Heskett ghesk...@wdtv.com wrote: On Thursday 04 September 2014 11:07:07 Viesturs Lācis did opine And Gene did reply: Hello! I have a strange situation: Stepper motor of Z axis on a cnc router is losing it's position - doing a series of numerous holes in material will end up with various depths of holes. The strange part is: 1) for each time, when machine is running, it will lose position only in one direction; if holes are getting deeper, then they only get deeper, not the other way; 2) the direction of drift will change randomly as machine is restarted and only then; simply running another g-code file will not change the direction of drift; There is Nema23 stepper motor and Gecko stepper driver. Motor cable is checked for loose contact, step/dir signal lines are checked for loose contact, ballscrew and linear rails are checked for any damage to cause extra resistance in particular direction, the clutch between motor and ballscrew is checked not to slip. I am totally out of ideas, where to look. Has anyone ever experienced anything like that? What puzzles me most is the consistency to maintain direction of drift and yet randomly change, when whole system is restarted, so any suggestions will be appreciated. Viesturs Can we assume you have lengthened the dirsetup and dirhold settings? I don't have any gecko's, but this sure seems to be an ongoing problem with them. From previous messages, it seems a trip to gecko for repairs fixes it, but a random direction fixed at machine boot? Thats weird, and I've no clue. Cheers, Gene Heskett -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Genes Web page http://geneslinuxbox.net:6309/gene US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS -- Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Steppers losing position
As you sad : Yes, as I said, motor is drifting in particular direction, which may change (not always), if system is restarted, but the direction of drift does not change, once the system is running - if it gradually goes up, then it does so; if down, then it keeps getting deeper. Means that the drift in is both directions. But the axis (motor) is always making more space than expected , isn't it ? Alex On Thu, Sep 4, 2014 at 5:29 PM, alex chiosso achio...@gmail.com wrote: As Gene is suggesting , here http://linuxcnc.org/index.php/english/forum/16-stepconf-wizard/27293-solved-tuning-stepper-motor-with-gecko-201-driver?start=10 is a discussion on the forum regarding problems with steps and Gecko Drive . A question for you ... the router is brand new (I mean that you have finished the setup) or is a already working machine ? This question is to understand if the machine was working fine before and later start with the problem you are mentioning. Alex On Thu, Sep 4, 2014 at 5:21 PM, Gene Heskett ghesk...@wdtv.com wrote: On Thursday 04 September 2014 11:07:07 Viesturs Lācis did opine And Gene did reply: Hello! I have a strange situation: Stepper motor of Z axis on a cnc router is losing it's position - doing a series of numerous holes in material will end up with various depths of holes. The strange part is: 1) for each time, when machine is running, it will lose position only in one direction; if holes are getting deeper, then they only get deeper, not the other way; 2) the direction of drift will change randomly as machine is restarted and only then; simply running another g-code file will not change the direction of drift; There is Nema23 stepper motor and Gecko stepper driver. Motor cable is checked for loose contact, step/dir signal lines are checked for loose contact, ballscrew and linear rails are checked for any damage to cause extra resistance in particular direction, the clutch between motor and ballscrew is checked not to slip. I am totally out of ideas, where to look. Has anyone ever experienced anything like that? What puzzles me most is the consistency to maintain direction of drift and yet randomly change, when whole system is restarted, so any suggestions will be appreciated. Viesturs Can we assume you have lengthened the dirsetup and dirhold settings? I don't have any gecko's, but this sure seems to be an ongoing problem with them. From previous messages, it seems a trip to gecko for repairs fixes it, but a random direction fixed at machine boot? Thats weird, and I've no clue. Cheers, Gene Heskett -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Genes Web page http://geneslinuxbox.net:6309/gene US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS -- Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Steppers losing position
2014-09-04 18:29 GMT+03:00 alex chiosso achio...@gmail.com: A question for you ... the router is brand new (I mean that you have finished the setup) or is a already working machine ? I built that machine 3 years ago. Viesturs -- Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Steppers losing position
2014-09-04 18:32 GMT+03:00 alex chiosso achio...@gmail.com: Means that the drift in is both directions. But the axis (motor) is always making more space than expected , isn't it ? Yes, drift can be in any direction, but the change of direction happens only on system restart. Viesturs -- Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Steppers losing position
This seems to be an electrical problem . Have you tried to perform the machine cycle (i.e the holes drilling) in dry mode (no material) and with a reduced feed rate ? Just to understand if is related to the step frequency and torque . Alex On Thu, Sep 4, 2014 at 5:37 PM, Viesturs Lācis viesturs.la...@gmail.com wrote: 2014-09-04 18:32 GMT+03:00 alex chiosso achio...@gmail.com: Means that the drift in is both directions. But the axis (motor) is always making more space than expected , isn't it ? Yes, drift can be in any direction, but the change of direction happens only on system restart. Viesturs -- Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Steppers losing position
On 4 September 2014 16:07, Viesturs Lācis viesturs.la...@gmail.com wrote: There is Nema23 stepper motor and Gecko stepper driver. A vaguely recall hearing of one channel of the G540 going bad and then also that inverting the step signals makes it good again. It certainly seems that it might be worth at least attempting an inversion of the step pin. (both the parport and Mesa drivers allow an output pin to be inverted) -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Steppers losing position
Greetings -Original Message- From: Viesturs Lācis [mailto:viesturs.la...@gmail.com] 2014-09-04 18:16 GMT+03:00 alex chiosso achio...@gmail.com: If the holes are deeper doesn't it means that the motor is making more steps and not less ? Is it possible that you have extra steps due to noises or bad connections PC --- BoB --- Gecko Drive ? Yes, as I said, motor is drifting in particular direction, which may change (not always), if system is restarted, but the direction of drift does not change, once the system is running - if it gradually goes up, then it does so; if down, then it keeps getting deeper. There is no BoB, step/dir signals go directly from 5i23 to Gecko. Two thoughts - sadly neither addressing the direction of drift constant for a given boot symptom: (a) It is not possible to infer if steps are being lost or gained from a series of holes. Noise might give additional steps - but IMO this is unusual - but this might be when going down when holes get deeper or going up when holes get shallower. (b) It might be worth checking that the 5i23 pullups are set to 5volt for the connector you are using. The 5i20 manual says that, with 3v3 pullups, optos connected to a 5 volt rail may not fully turn off. John Prentice -- Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Steppers losing position
On 9/4/2014 9:07 AM, Viesturs Lācis wrote: Hello! I have a strange situation: Stepper motor of Z axis on a cnc router is losing it's position - doing a series of numerous holes in material will end up with various depths of holes. The strange part is: 1) for each time, when machine is running, it will lose position only in one direction; if holes are getting deeper, then they only get deeper, not the other way; 2) the direction of drift will change randomly as machine is restarted and only then; simply running another g-code file will not change the direction of drift; First thing I'd look at is your spindle speed and feed rate. If the bit is pulling itself into the work faster than the control is commanding, it can force the motor to 'run ahead' of the commanded steps. If the control is trying to push the bit in faster than it can cut, the effect is a 'push back' where the step signals go to the motor but it doesn't actually move. Combine either or both with a slight variance in density of the material and you'll get randomness. If tweaking the speed and feed doesn't completely cure it there are hardware solutions. Were this my machine I'd find a way to put a scale (magnetic type, crud and fluids don't mess them up and can be cut to length) or rotary encoder on so the control always knows where the axis is. Another possibility is more power. Put on a larger stepper with more torque so it can't be pulled ahead of or pushed behind the stream of step signals. Another cause of it might be variability of chip loading in the bit. What do you have for keeping the bit clear? For material that can't take liquids use an air nozzle and vacuum. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com -- Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Steppers losing position
On 9/4/2014 9:07 AM, Viesturs Lācis wrote: Hello! I have a strange situation: Stepper motor of Z axis on a cnc router is losing it's position - doing a series of numerous holes in material will end up with various depths of holes. Just thought of this, have you tried homing the Z axis up before drilling each hole? That would reset the position so the control will always start from the same known position each time. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com -- Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
