Z-axis does not return to correct zero position


Results 1 to 5 of 5

Thread: Z-axis does not return to correct zero position

  1. #1
    Member samnot's Avatar
    Join Date
    Jan 2021
    Posts
    3
    Downloads
    0
    Uploads
    0

    Question Z-axis does not return to correct zero position

    Hello all!

    I'm new to this forum and I'm looking for some help with a DIY CNC machine.
    I am mostly finished with my build, just wrapping up some loose ends and trying to learn a lot about CAM and machining. However, I am having an issue with my Z-axis. A little background on my machine:

    -Welded steel frame, 1500mm x 1000mm x 400mm linear guide rails
    -2.2kw spindle motor
    -Arduino Uno running GRBL for motion control
    -PC running Universal Gcode Sender (UGS) with usb connection to the Arduino
    -Inductive limit switches

    Now to my problem. When I set up a workpiece, I move the tool to my desired position and zero the work coordinates. Then, I home the machine. Next, I start the gcode program and the machine heads to start cutting. The problem lies with the Z-axis. When the machine returns to the workpiece zero I set previously, the Z axis goes too low. It goes exactly 1mm to low. I have learned that this error distance corresponds directly to my homing rebound distance (the distance each axis rebounds off the homing switch after home is set). So if I set my rebound distance to 5mm in the firmware settings, the error in my Z-axis is 5mm. The confusing part is that this only happens to the Z-axis, not X or Y. The settings appear to be the same for X, Y, and Z, but I must be missing something.

    I have tried basic troubleshooting to find out that it is the rebound distance that is the issue. It happens every time after workpiece zero is set.

    If anyone knows what could fix this issue, I would be forever grateful!

    Thank you all,

    -Samnot



  2. #2
    Member
    Join Date
    Apr 2004
    Location
    Oakland CA USA
    Posts
    5253
    Downloads
    0
    Uploads
    0

    Default Re: Z-axis does not return to correct zero position

    What happens when you set your Z-axis rebound distance to zero?

    Andrew Werby
    https://computersculpture.com/


  3. #3
    Community Moderator ger21's Avatar
    Join Date
    Mar 2003
    Location
    Shelby Township
    Posts
    35373
    Downloads
    1
    Uploads
    0

    Default Re: Z-axis does not return to correct zero position

    Never used GRBL, but you should be homing the machine first, then setting you're zero position.

    Gerry

    UCCNC 2017 Screenset
    http://www.thecncwoodworker.com/2017.html

    Mach3 2010 Screenset
    http://www.thecncwoodworker.com/2010.html

    JointCAM - CNC Dovetails & Box Joints
    http://www.g-forcecnc.com/jointcam.html

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)


  4. #4
    Member samnot's Avatar
    Join Date
    Jan 2021
    Posts
    3
    Downloads
    0
    Uploads
    0

    Default Re: Z-axis does not return to correct zero position

    I forgot to mention that... I home the machine on power up, so that was done before setting workpiece zero.



  5. #5
    Member samnot's Avatar
    Join Date
    Jan 2021
    Posts
    3
    Downloads
    0
    Uploads
    0

    Default Re: Z-axis does not return to correct zero position

    Quote Originally Posted by awerby View Post
    What happens when you set your Z-axis rebound distance to zero?
    I will try that and see what happens, thanks for the idea. I would think my machine would error out because the homing switches also act as hard stops. At 0mm rebound, the hard stops would be triggered causing issues... maybe? I will see.



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
  •  


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

Z-axis does not return to correct zero position

Z-axis does not return to correct zero position

Z-axis does not return to correct zero position