Hi All,

I have a Hardinge CHNC 1 with a Siemens 810T controller, I have a strange problem?

When the machine reads an M01 (or tool call) command the spindles sometimes will not come to a complete halt and spins at around 12 to 15 Rpm? If this happens
during a tool change the machine just sits waiting for the spindle to stop, sometimes it will eventually stop and so the tool change happens and the machine
carries on thro its cycle until the next M01 or tool call,

The machine is run on a three phase converter and has been good for a long while, I am wondering if there is any voltage instability from the converter could this cause
an issue (I have not checked the outputs from the 3 phase converter for a long while)

Sometimes shutting the machine down (and the phase converter) seems to clear the problem and the machine runs for the rest of the day ok?

Thanks for any help or ideas!

Allen.