Router Crash


Results 1 to 5 of 5

Thread: Router Crash

  1. #1
    Registered
    Join Date
    Jul 2007
    Location
    Canada
    Posts
    133
    Downloads
    0
    Uploads
    0

    Default Router Crash

    I'm sure most of us have at least one crash under our belt, and hopefully we learn something so mistakes aren't repeated again. The first big crash I had was carving a 3D tool path with a 3/4" bit. At first I thought something had gone horribly wrong with the G code as the cutter plunged beyond full depth and then tried to make a cut. I hit the E stop pretty quick, and thankfully there was no permanent damage.

    After some investigation, I found the case was some dirt had got into the ball nut and caused it to seize, and the coupling between the screw and motor slipped and the Z height was off. So I've dismantled, cleaned and reassembled everything, and I've also added pins that go through the coupler and screw so that there is no chance of slippage. That combined with servos that will fault and shut down if they're too far out of position should be enough, right?

    I thought so until another crash happened today. This time I checked everything and there were no sheared pins or any evidence of slippage, but my Z height was 10mm below where it should have been. That's two full rotations out of position that the encoder didn't pick up on, or something else has gone wrong. My VFD shut down the spindle and the x axis faulted so at least I know some of the systems are working, but I can't think of how a servo driven ball screw could get so far out of position. Looking at the G code where it crashed, it was just after a large retract and rapid move, so it likely lost position lifting up, and then plunged too far down into the block of maple I was cutting and just started to move in the x and y when it crashed.

    Has anyone experienced anything similar to this and how did you end up fixing it? I've run the same program before without issues, and I'd really like to let it run unattended, but this crash is making me a bit paranoid.

    Similar Threads:


  2. #2
    Registered Jim Dawson's Avatar
    Join Date
    Dec 2013
    Posts
    1092
    Downloads
    0
    Uploads
    0

    Default Re: Router Crash

    Sounds like you are losing the encoder signal. Could be the encoder, wiring, or board, hard to tell.



  3. #3
    Community Moderator ger21's Avatar
    Join Date
    Mar 2003
    Location
    United States
    Posts
    29634
    Downloads
    0
    Uploads
    0

    Default Re: Router Crash

    A servo should fault if it loses position, so something is definitely wrong.


    And you should NEVER let a machine cutting wood run unattended. There's always a serious risk of fire, even if the machine does nothing wrong. Pieces of wood can break loose, and get caught in places where the collet nut can rub, which can create enough friction to start burning in seconds.
    Machines with vacuum tables are even more dangerous, as the suction pulls the fire under the table. You don't even know it's burning.

    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
    Registered
    Join Date
    Jul 2007
    Location
    Canada
    Posts
    133
    Downloads
    0
    Uploads
    0

    Default Re: Router Crash

    I've checked the connections for the encoder and everything looks fine, but I'm not sure how I'd test them further without an oscilloscope.

    As far as running unattended, I'm not planning on leaving the shop, but I do like to work on other things nearby, especially when I'm running a 40 minute long program. I keep the wireless controller nearby so I can easily stop it if I heard something or saw smoke, but in this case, the couple seconds it took for me to grab the remote was long enough for the bit to bury itself and trip the emergency shutoff on its own.



  5. #5
    Community Moderator ger21's Avatar
    Join Date
    Mar 2003
    Location
    United States
    Posts
    29634
    Downloads
    0
    Uploads
    0

    Default Re: Router Crash

    Are you sure it's not mechanical? I would expect that the drive would fault if there was an encoder issue?

    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)


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

Router Crash
Router Crash