If the Z won't home on the SS 408, it could be for a few reasons.


Diagnose Alarm meaning:  Search for code in Mitusbishi Alarms to match to Alarms on Servos in grey box on the machine


You might get AL 52.3 or AL 51.2 on the Z controller for this issue.



Possible Solutions:


1) Homing Switch is Dead


Test: 

  1. Push Home button on WinCNC. If you see a red triangle when switch is hit (top) next to Z line then switch is working.




2) Z-Balancer Shaft is Dirty


Fix: 

  1. Use WD-40 on a lint-free towel to wipe down and clean shaft
  2. Snug up any looseness in shaft with 3/8" wrench (tightens at bottom on flatten sides of shaft)
  3. Try to home, if successful, you're done.



3) Balancer Shaft is Too Loose or Tight


Fix: Use a 3/8" wrench to hand snug shaft. Wrench at flatten spots on shaft at bottom.