584,802 active members*
4,926 visitors online*
Register for free
Login
IndustryArena Forum > MetalWorking Machines > Milltronics > Z axis servo brake failure
Results 1 to 2 of 2
  1. #1
    Join Date
    Jun 2013
    Posts
    16

    Z axis servo brake failure

    A few weeks ago my Z axis stopped moving, the brake was no longer being released. After probing wires I determined that the windings inside the brake had failed as it was an open circuit.

    Sorry I didn't take any pictures of the servo disassembly but the brake is bolted to the mounting plate of the servo motor. Remove the 3 allen head screws in the center circle and the 4 5/16 head nyloc nuts and pull the bottom plate off. Then use a small gear puller to pull the bearing as it's a slight press fit onto the shaft and then the brake will drop out.

    Since the bobbin for the windings is glued into the brake I had to machine a new one from delrin.

    Attachment 450312

    Then I used my little CNC lathe to wind the 35g wire because I could run it for a set time at a consistent speed to count the windings. My rough counting of the windings on the original was 2800 wraps, but my calculations said I needed closer to 3800 wraps to get the 13w consumption at 90v which should yield 623ohm. I measured the one on my other mill at 575ohm so there is some wiggle room.

    Attachment 450314

    I ended up with around 3600 wraps as I stopped early to leave room on the bobbin for the leads which ended up at 585ohm. Maybe 36g wire would have been better but I measured the original wire at 0.0061" which is 35g.

    Attachment 450316

    All glued into place.

    Attachment 450318

  2. #2
    Join Date
    Jun 2010
    Posts
    132

    Re: Z axis servo brake failure

    Congratulation's, Good write up

Similar Threads

  1. Replies: 3
    Last Post: 06-01-2021, 09:56 PM
  2. Replies: 2
    Last Post: 07-27-2015, 07:02 PM
  3. A axis brake failure on MAZAK Variaxis.
    By Mat Mexico in forum Mazak, Mitsubishi, Mazatrol
    Replies: 0
    Last Post: 10-29-2013, 10:38 PM
  4. Dynamic Brake failure
    By Gncc50 in forum Bridgeport / Hardinge Mills
    Replies: 4
    Last Post: 08-24-2011, 01:38 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
  •