502,388 active members
8,266 visitors online
Register for free
Login
IndustryArena Forum > CNC Electronics > Servo Motors / Drives > DMM Servos with DYN4 Drives on G0704 Random Alarm Issue
Page 1 of 2 12
Results 1 to 12 of 22
  1. #1
    Registered
    Join Date
    Jan 2016
    Posts
    57

    DMM Servos with DYN4 Drives on G0704 Random Alarm Issue

    I recently upgraded the steppers on my G0704 from steppers to DMM 400W servos on the X & Y, and 750W on the Z, all with DYN4 drives. Everything progressed well until a shakedown run when the 400W X and Y axes started throwing random servo alarms for Lost Phase or Overheat. Sometimes the alarms occur less than a minute into a program, so the motor is still cold, so the Over Heat is false. The servos were auto-tuned using the DMM software. Gear and Line settings are 500 & 500. I'm using Mach3 with a 25kHz pulse, though I've also tried a 45kHz pulse which had the same results. DMM support has been great with many emails exchanged, but thus far we're unable to track down the cause. The 400W servos behave very well, until at some random point in the program either the X or the Y servo will alarm out. The drives are connected to a C11GD breakout board and are set to run in Pulse/Dir mode per the DMM guide. The 750W Z axis has performed very well from day 1, and has never alarmed out, so I don't think its a random noise issue, or a pulsing issue from Mach3 since the Z is perfectly healthy. Has anyone experienced DMM servos/drives plagued with "false" alarms? Any feedback is appreciated.

    Has anyone had success with the 400W DMM servos on a G0704 type machine? They seem to have plenty of power to slew the axes at over 200 IPM but this alarm issue is making wonder if they are undersized. On paper, they produce more than twice the power of the Nema 23 steppers they replaced.

    DMM has recommended that I move from a brand new $100 C11GD breakout board to a Smoothstepper. They believe its a pulse related issue, exacerbated by the C11GD breakout board. I don't agree since the Z-axis has been perfect from day 1. The 400W servos are driven by DYN4-L01 drives, wired at 120V AC with all the proper Shaffner EMI filters in place, per the DMM guide. I have 6A filters on the drive's power side, 1A on the logic side, and a large 30A filter on the main AC input, per the guide. I was surprised that these took 120V AC rather than 240V but these motors are only 60V so DMM only recommends 120V AC for these. The z-axis is wired at 240V per the DMM guide.

    Things I've already tried"
    1. Re-tuned the troublesome X and Y axes a dozen times, no change.
    2. Stepped down from a 45kHz pulse to a 25kHz pulse, no change.
    3. De-tuned the Mach 3 axis velocity and accelerations way down to benign values, no change.
    4. Run a dozen different programs to make sure its not bad G-code. Issue occurs in all programs, even during slow 15IPM light duty cuts.

    -Mike

  2. #2

    Join Date
    Jan 2005
    Posts
    10009

    Re: DMM Servos with DYN4 Drives on G0704 Random Alarm Issue

    Quote Originally Posted by mikegiraud View Post
    I recently upgraded the steppers on my G0704 from steppers to DMM 400W servos on the X & Y, and 750W on the Z, all with DYN4 drives. Everything progressed well until a shakedown run when the 400W X and Y axes started throwing random servo alarms for Lost Phase or Overheat. Sometimes the alarms occur less than a minute into a program, so the motor is still cold, so the Over Heat is false. The servos were auto-tuned using the DMM software. Gear and Line settings are 500 & 500. I'm using Mach3 with a 25kHz pulse, though I've also tried a 45kHz pulse which had the same results. DMM support has been great with many emails exchanged, but thus far we're unable to track down the cause. The 400W servos behave very well, until at some random point in the program either the X or the Y servo will alarm out. The drives are connected to a C11GD breakout board and are set to run in Pulse/Dir mode per the DMM guide. The 750W Z axis has performed very well from day 1, and has never alarmed out, so I don't think its a random noise issue, or a pulsing issue from Mach3 since the Z is perfectly healthy. Has anyone experienced DMM servos/drives plagued with "false" alarms? Any feedback is appreciated.

    Has anyone had success with the 400W DMM servos on a G0704 type machine? They seem to have plenty of power to slew the axes at over 200 IPM but this alarm issue is making wonder if they are undersized. On paper, they produce more than twice the power of the Nema 23 steppers they replaced.

    DMM has recommended that I move from a brand new $100 C11GD breakout board to a Smoothstepper. They believe its a pulse related issue, exacerbated by the C11GD breakout board. I don't agree since the Z-axis has been perfect from day 1. The 400W servos are driven by DYN4-L01 drives, wired at 120V AC with all the proper Shaffner EMI filters in place, per the DMM guide. I have 6A filters on the drive's power side, 1A on the logic side, and a large 30A filter on the main AC input, per the guide. I was surprised that these took 120V AC rather than 240V but these motors are only 60V so DMM only recommends 120V AC for these. The z-axis is wired at 240V per the DMM guide.

    Things I've already tried"
    1. Re-tuned the troublesome X and Y axes a dozen times, no change.
    2. Stepped down from a 45kHz pulse to a 25kHz pulse, no change.
    3. De-tuned the Mach 3 axis velocity and accelerations way down to benign values, no change.
    4. Run a dozen different programs to make sure its not bad G-code. Issue occurs in all programs, even during slow 15IPM light duty cuts.

    -Mike
    Yes your pulse rate is way to low for any servos, what works well is the UC100 which is 100Khz but even with this you won't get max RPM so yes smooth stepper if you want the max out of what you have

    To get going up your configuration to 65Khz and lower the Velocity and Acceleration this will be mostly Velocity related problem in Mach3 so drop that down until you don't fault the drives

    With 100Khz you can get around 2400RPM to 2850 motor RPM with a Smooth Stepper you will get max motor RPM

    You may be on the light side with the 400w motors for X and Y Axes also are these 1:1 or 2:1 2:1 is what is normally needed for X and Y axes or 1:1 use the 750w motor
    Mactec54

  3. #3
    Registered
    Join Date
    Jan 2016
    Posts
    57

    Re: DMM Servos with DYN4 Drives on G0704 Random Alarm Issue

    Mactec54,

    Thanks for the solid feedback. I'll definitely move to the smoothstepper. Ill try the 65kHz as a temporary limp along solution as well.

    All my axes are direct drive 1:1. The 400W servos produce more torque than the old Nema 23 steppers at all speeds, so I think I'm ok on motor power, however your point is well taken. If the Smoothstepper doesnt solve this, I'll need to step up to the 750W servos.

    -Mike

    Sent from my SM-G892U using Tapatalk

  4. #4

    Join Date
    Jan 2005
    Posts
    10009

    Re: DMM Servos with DYN4 Drives on G0704 Random Alarm Issue

    Quote Originally Posted by mikegiraud View Post
    Mactec54,

    Thanks for the solid feedback. I'll definitely move to the smoothstepper. Ill try the 65kHz as a temporary limp along solution as well.

    All my axes are direct drive 1:1. The 400W servos produce more torque than the old Nema 23 steppers at all speeds, so I think I'm ok on motor power, however your point is well taken. If the Smoothstepper doesnt solve this, I'll need to step up to the 750W servos.

    -Mike

    Sent from my SM-G892U using Tapatalk
    You can go to 75Khz if your computer it able to support it most computers can do 100Khz but after 75Khz it not that reliable

    1:1 is most likely the problem for the 400w motor 2:1 is the norm for a machine like this with that size servo, you are right on the edge of yes I can no I can't at 1:1
    Mactec54

  5. #5
    Registered
    Join Date
    Jan 2016
    Posts
    57

    Re: DMM Servos with DYN4 Drives on G0704 Random Alarm Issue

    Thanks so much. The Smoothstepper is on order. I'll start with that then if needed step up to the 750W motors/drives. I appreciate your inputs.

    Sent from my SM-G892U using Tapatalk

  6. #6
    Registered
    Join Date
    Jun 2015
    Posts
    842

    Re: DMM Servos with DYN4 Drives on G0704 Random Alarm Issue

    Quote Originally Posted by mactec54 View Post
    Yes your pulse rate is way to low for any servos, what works well is the UC100 which is 100Khz but even with this you won't get max RPM so yes smooth stepper if you want the max out of what you have

    To get going up your configuration to 65Khz and lower the Velocity and Acceleration this will be mostly Velocity related problem in Mach3 so drop that down until you don't fault the drives

    With 100Khz you can get around 2400RPM to 2850 motor RPM with a Smooth Stepper you will get max motor RPM

    You may be on the light side with the 400w motors for X and Y Axes also are these 1:1 or 2:1 2:1 is what is normally needed for X and Y axes or 1:1 use the 750w motor
    With a UC400ETH/UC300ETH/AXBB-E you also get max RPM, they can do 400kHz.

  7. #7

    Join Date
    Jan 2005
    Posts
    10009

    Re: DMM Servos with DYN4 Drives on G0704 Random Alarm Issue

    Quote Originally Posted by OlfCNC View Post
    With a UC400ETH/UC300ETH/AXBB-E you also get max RPM, they can do 400kHz.
    Correct, but a Smooth Stepper is a whole lot better than a UC400 and was designed to use with Mach3 which he can use also with Mach4 if at any time he wants to upgrade
    Mactec54

  8. #8
    Registered
    Join Date
    Jun 2015
    Posts
    842

    Re: DMM Servos with DYN4 Drives on G0704 Random Alarm Issue

    Haha, your feelings again mactec. The UC400ETH is a whole better than the Smoothstepper, it works with 3 softwares (Mach3, Mach4, UCCNC) and works flawless.
    So he can upgrade any time to mach4 when he wants with the UC400 or even better if he upgrade to UCCNC as it is superior to Mach XY.
    It is funny that for you everything is better than what I say, just because I'm saying it.

  9. #9

    Join Date
    Jan 2005
    Posts
    10009

    Re: DMM Servos with DYN4 Drives on G0704 Random Alarm Issue

    Quote Originally Posted by OlfCNC View Post
    Haha, your feelings again mactec. The UC400ETH is a whole better than the Smoothstepper, it works with 3 softwares (Mach3, Mach4, UCCNC) and works flawless.
    So he can upgrade any time to mach4 when he wants with the UC400 or even better if he upgrade to UCCNC as it is superior to Mach XY.
    It is funny that for you everything is better than what I say, just because I'm saying it.
    It is only 400Khz does not compare in any way :wave:
    Mactec54

  10. #10
    Registered
    Join Date
    Jun 2015
    Posts
    842

    Re: DMM Servos with DYN4 Drives on G0704 Random Alarm Issue

    Quote Originally Posted by mactec54 View Post
    It is only 400Khz does not compare in any way :wave:
    "just 400kHz"? Show me a stepper drive which can input more than that.
    And tell me how safe is to put MHz signals into cables in noisy environments.
    Doing that is megalomanic idiotism. :wave:
    Furthermore the OP needs not much more than 100kHz frequency.

  11. #11
    Registered
    Join Date
    Feb 2008
    Posts
    576

    Re: DMM Servos with DYN4 Drives on G0704 Random Alarm Issue

    Quote Originally Posted by OlfCNC View Post
    "just 400kHz"? Show me a stepper drive which can input more than that.
    And tell me how safe is to put MHz signals into cables in noisy environments.
    Doing that is megalomanic idiotism. :wave:
    Furthermore the OP needs not much more than 100kHz frequency.
    Step/dir or Quadrature driven servos often have MHz step rates to get high speed and resolution
    For example if you had a 20000 step/turn servo, 3000 RPM would requite a 1MHz step rate.
    These signals are usually conveyed with differential signaling for noise immunity.

    Higher step rate capability also suggests a cleaner step signal as the jitter and beats
    of the step rate against the fundamental clock rate are reduced.

    For example, our step-generators can generate steps to 10 MHz and have a base clock of 100 MHz...

  12. #12
    Registered
    Join Date
    Jun 2015
    Posts
    842

    Re: DMM Servos with DYN4 Drives on G0704 Random Alarm Issue

    The time base of 400kHz is 2.5 microseconds, I don't think that a cleaner step signal is needed than that.
    MHz signals are very short needle like pulses I would not run my system with that fast signals but ofcourse everybody do what they want to, it is not my problem.

Page 1 of 2 12

Similar Threads

  1. Anyone with experience from DYN4 drives and LinuxCNC?
    By nschmidt in forum Dmm Technology
    Replies: 2
    Last Post: 05-29-2019, 06:14 PM
  2. Replies: 5
    Last Post: 05-04-2019, 05:08 AM
  3. Recommended Voltage for DYN4 Drives/Motors
    By firepong in forum Dmm Technology
    Replies: 15
    Last Post: 02-26-2019, 06:56 AM
  4. DMM Tech DYN4 cnc servo drives motors cables I/O boards full 3 axis system
    By DennisCNC in forum Newly Posted Classifieds Listings
    Replies: 1
    Last Post: 12-13-2017, 10:07 PM
  5. Replies: 58
    Last Post: 03-06-2017, 04:33 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •