VAST XXT Sensor Triggering Failure – Spectrum 7/10/6 CMM with RDS Head

[[Pa...]]

Fault description

The equipment began exhibiting a spontaneous fault during measurement operations, without any prior hardware or software intervention.

The head performs all indexing movements normally, indicating that the RDS positioning system appears to be functioning correctly.

However, when a measurement begins, the VAST XXT sensor fails to trigger (detect contact with the workpiece) at any A=180° position.
The machine continues to advance past the expected contact point as if the sensor remained inactive preventing point acquisition.

Observed conditions

* The issue occurs with any stylus configuration at A=180°.
* The sensor does not trigger during measurement.
* Head indexing proceeds normally.
* No collisions were identified immediately prior to the fault's onset.
* The fault occurred spontaneously.

I would like to know if anyone has encountered similar behavior and what additional procedures are recommended to isolate the cause before replacing the sensor or opening a service ticket.

 

[[Ke...]]

Is it possible that the XXT was crashed and it was not reported?

I have seen similar behavior and I was able to determine that the XXT was broken, by removing it and inspecting it. There are small parts that may get broken, and it will interfere with the triggering (all other behavior normal, including qualification). 

[[Pa...]]

Não acredito que o problema esteja no XXT, em outras posições funciona sem problemas. Somente quando RDS-CAA esta em A= 180° não há comunicação.

[[Jo...]]

This is exactly how our RDS head behaved when it was dying.  Certain angles were "bad".  We were able to get around it by using one rotation over from our bad angle, but eventually had to replace the RDS head at great expense.  Zeiss was not able to point to a cause for our failure and did not indicate that collisions would be a root cause.