Need Help!- Hardinge Quest 51 Sub Spindle Alarm

[pit-bull]

The following alarm is intermittent but very persistent;
7226 SPN 2 ISCONNECT C-VELO DETECT
This alarm has plagued me for a year ( maybe longer I have only been with this shop for a little over a year ). I have inspected and cleaned the sensor and reluctor on the sub spindle.
It appears that this situation has has been a problem for several years on this machine. Last year the sub-spindle sensor was replaced, I think that it's the sixth time this sensor to be replaced on the sub spindle.
The alarm will happen when the sub spindle is commanded to spin and when E-axis is moving and when E-axis is not moving.
It happens when running in automatic mode or when being jogged manually ( sub spindle spinning and jogging E-axis at the same time )
But the biggest headache is that it doesn't alarm out every time consistently.
The machine may run through 8 or so cycles then alarm out, sometimes it won't make it through 1 cycle then alarm out.
I'm talking with a Morris South tech. and waiting for him to call me back but maybe one of you Hardinge gurus can help me out.
Thanks in advance.

[Nawrocki4Life]

Hello I work for a company near Chicago that used to represent Hardinge for over 70 years untill they dropped us this year. I feel bad for all Hardinge customers b/c the new reps dont understand the equipment/controls well.

Seeing that you have replaced that expensive BZ sensor more then once takes that out of the question. Usually if that sensor is bad or "flakey" threading and syncing the sub to main has issues.

That sensor goes to a junction box underneath the sub's collet closer. From that junction box runs a cable to the sub's Amp/drive. It could be possible that, that cable could be the suspect.

The Amp/drive can also be the problem. If you look on each of the drives there is a label on the top cover. (covering the DC buss jumpers) If there is 2 of the same drives in your machine, you can swap the 2 and see if it follows the axis or drive. b/c its possible the drive is doing it.

Also on the control's PCB unit. "the mother board" there is a board on there that interfaces the drive to the control. Could be possible that, that board has the issue.

If you have no luck I would suggest to get a Fanuc tech in your building.


******EDITED PART******

I would also check the Sub's belt condition/tension

I would also check the Sub's brake to make sure it isnt rubbing on the drum or mis-aligned.

[cncmech]

pit,

Did you ever get this resolved?

Thanks

[Spiker604]

Very important, it could still be the bz sensor, take the bz sensor out pf the mounting bracket and look though the bracket at the bz sensor rings, the gap from the left side of the left ring to the edge of the mounting bracket should be the same as the gap from the right side of the right ring to the edge of the mounting bracket. basically you are making sure that the bz sensor is exactly centered over the rings as a set. do not worry where the gap between the rings falls, not important. it may be neccessary to add a shim where the mounting backet fastens to the casting to achieve this. once you have this, place the bz sensor back into the bracket using a .005" shim to set the gap between the bz sensor and the rings. hope this helps.