Skippy1 wrote: I did a fresh install of version 2.7 of linuxcnc, and then updated it to version 2.7.12. A few laps through PNCConf, and the spindle control was behaving beautifully.
Glad you got it working. There are many other enhancements in 2.7 so you should find that it was worth doing.
It would have been possible to stay with 2.5.5 and use the "abs" HAL component to achieve much the effect, but the upgrade will be a better solution.