584,841 active members*
4,388 visitors online*
Register for free
Login
IndustryArena Forum > CNC Electronics > Spindles / VFD > Turning on VFD Spindle causes stepper motors to jump around
Results 1 to 6 of 6
  1. #1
    Join Date
    Jul 2003
    Posts
    138

    Turning on VFD Spindle causes stepper motors to jump around

    When ever I turn turn on my VFD Spindle it causes my stepper motors to jump around so here are the details.

    1) CNC router is running at home with 220v dryer outlet for my VFD and 110v for my computer and stepper controller.
    2) Only happens when the computer is turned on with stepper controller.
    3) Jumping is most pronounced upon initial starting of spindle and seconds before stopping.
    4) Trying other outlets and circuits in the basement has the same result.
    5) The 220v and 110v circuits all terminate in same electrical panel.
    6) I am using shielded cable specifically designed for VFD's and shielded cable for all steppers.
    7) Power supply is made from a transformer and capacitor stuff in a separate enclosure.
    8) Only + and - leads have been brought form PS to Stepper controller box.
    9) Trying another stepper controller that I have which is identical with the exception of using a switching power supply was not affected by the VFD/spindle.

    Could my problem be grounding my power supply or stepper enclosure? All other components like, fan, BOB, stepper drivers, 24v and 12v convertors all only take the + and - leads and not the gnd.

    How my VFD is wired can be seen here:
    http://www.cnczone.com/forums/router...r_spindle.html

    Any help would be appreciated.

  2. #2
    Join Date
    Dec 2003
    Posts
    24216
    CNC, Mechatronics Integration and Custom Machine Design

    “Logic will get you from A to B. Imagination will take you everywhere.”
    Albert E.

  3. #3
    Join Date
    Jul 2003
    Posts
    138
    Thanks for your help Al.

    One thing I did not mention before is that power supply which is a round transformer is in a separate enclosure then my stepper drivers. Normally I would use a switching power supply and keep everything together but I thought a linear power supply would be a better. I have run cables between the two to carry the + and - lines to the stepper controller box but not the ground line. I am not sure if this makes a difference.

    I did try another stepper controller that I have which is identical with the exception of using a switching power supply and it was not affected by the VFD/spindle.

    Could my problem be grounding my power supply or stepper enclosure? All other components like, fan, BOB, stepper drivers, 24v and 12v convertors all only take the + and - leads and not the gnd.

  4. #4
    Join Date
    Dec 2003
    Posts
    24216
    All enclosures should be bonded to earth ground as well as the machine itself, with a ground taken to the VFD and on to the frame of the motor.
    Al.
    CNC, Mechatronics Integration and Custom Machine Design

    “Logic will get you from A to B. Imagination will take you everywhere.”
    Albert E.

  5. #5
    Join Date
    Jul 2003
    Posts
    138

    Problem with power supply

    When I swap out the power supply with a switching PS the noise problem goes away.

    I have included a picture of my PS in the blue case, can anyone tell from looking at it if there are any obvious problems?

    Thx.

  6. #6
    Join Date
    Dec 2003
    Posts
    24216
    Usually there is not a lot of interference from a linear supply, especially a toroidal where the magnetic field is retained in the core?
    It is best really to have it in an all in one enclosure, or at least well bonded to the main enclosure, I notice you mention that the VFD supply is a different source? Make sure the grounds from this source are well bonded to the other source of earth grounds such as other 120v sockets, also the VFD and motor frame.
    As I have mentioned many times, the PC 5v/12v common is connected to the same earth ground as the VFD is.
    Al.
    CNC, Mechatronics Integration and Custom Machine Design

    “Logic will get you from A to B. Imagination will take you everywhere.”
    Albert E.

Similar Threads

  1. Replies: 2
    Last Post: 07-12-2009, 10:10 AM
  2. What causes a stepper motor to jump steps
    By erkiwi in forum Stepper Motors / Drives
    Replies: 4
    Last Post: 02-20-2008, 08:26 PM
  3. Spindle motor stopped, stepper motors flaky...
    By americanbehn in forum DNC Problems and Solutions
    Replies: 1
    Last Post: 11-06-2007, 03:25 AM
  4. Manual turning of stepper motors
    By Pat in forum Stepper Motors / Drives
    Replies: 1
    Last Post: 08-08-2005, 09:04 PM

Posting Permissions

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