Lathe - screw cutting - 5I25 setup difficulty

I am working towards converting a manual lathe to CNC.
I have the Mesa 5i25 board, and using 'mesaflash', I have now correctly configured it with the prob_rfx2 firmware.
Using the 'Pncconf Wizard', I have successfully configured two stepgens which drive the X and Z axis motors (via their individual motor drives of course!) - these work in Pncconf and also work when running Linuxcnc with the output files created using Pncconf. So far so good, but I need a spindle encoder so that I can cut screw threads. I have a proper spindle encoder fitted to the lathe (not yet wired), but I come unstuck trying to configure Pncconf to include a spindle encoder. Thus far all my attempts at including a 'Spindle Encoder' result in a Pncconf output which prevents Linuxcnc from running. Instead a 'LinuxCNC Errors' window opens, containing far too much information for my tired mind to wrestle with, but perhaps the 'important' line is the one following 'Debug file information:', which reads:-
./LatheJun2016.hal:200: parameter or pin 'scale.spindle.gain' not found

Any thoughts will be much appreciated. All I want for now is to control the two axis motors synced up to measured spindle speed. For now the spindle motor is controlled manually.

Hardware is minimal, no 'BOB's, have so far wired 5i25 step and dir outputs to the two motor drives and these all work

Thanks Andy,
hal file attached

looks like the scale component for the spindle feedback velocity is missing
I would change
loadrt scale names=scale.gear
to:
loadrt scale names=scale.gear,scale.spindle
and add:
addf scale.spindle servo-thread

Editing the hal file, changing
loadrt scale names=scale.gear
to:
loadrt scale names=scale.gear,scale.spindle
causes the debug message to change to
./LatheJun2016.hal:210: parameter or pin 'lowpass.spindle.gain' not found

so presumably this has solved the problem of the missing 'scale.spindle' only to reveal a missing 'lowpass.spindle'

Lines 209 and 210 of the hal file read
setp scale.spindle.gain 60
setp lowpass.spindle.gain 1.000000

Next, I guessed I might try adding
loadrt lowpass names=lowpass.spindle
and
addf lowpass.spindle servo-thread
This apparently caused no ill effect but changed the error message again to
./LatheJun2016.hal:215: Pin 'abs.spindle.in' does not exist.

Mmmmmm.......

Yes, thanks,
I now have a hal file that allows Linuxcnc to start and run again, and I have once again the two axis motors on the bench spinning to and fro running a test G code prog.

Quite what happens when I physically connect the spindle encoder will only be known once I've migrated all this stuff off the electronics bench and into the workshop - a few days perhaps, I'll let you know what happens, and thanks again.