Configuring a stepper as spindle motor

How does one configure a stepper motor as spindle? Does Stepconf cater for this at all?

Thanks for the advice.
I mounted a stepper motor horizontally on the table, driving it as a spindle, removed the original spindle motor from the Z-axis and attached a lathe tool to the z-axis.

I now have a lathe for making my own collets -- working vey well indeed (just dont try to cut too deep in a single pass or the stepper motor will stall).

Having done all that, I now have a new question:

When I configure the A axis in the normal way with StepConf (not driving the spindle), all the controls become irratic and slow.
Jogging becomes almost impossible, the control takes long to respond and then the axis keeps moving long after the key has been released.
Does anyone else experience this ?

Note that the slow response happens on all the axis, this is what the config looks like:

INI File entries:

[AXIS_3]
TYPE = ANGULAR
HOME = 0.0
MAX_VELOCITY = 2880.0
MAX_ACCELERATION = 14400.0
STEPGEN_MAXACCEL = 18000.0
SCALE = 1.11111111111
FERROR = 25
MIN_FERROR = .25
MIN_LIMIT = -3600.0
MAX_LIMIT = 0.001
HOME_OFFSET = 0.000000
HOME_SEARCH_VEL = 200.000000
HOME_LATCH_VEL = -200.000000
HOME_SEQUENCE = 3

Hal File entries:

setp stepgen.3.position-scale [AXIS_3]SCALE
setp stepgen.3.steplen 1
setp stepgen.3.stepspace 1
setp stepgen.3.dirhold 55000
setp stepgen.3.dirsetup 55000
setp stepgen.3.maxaccel [AXIS_3]STEPGEN_MAXACCEL
net apos-cmd axis.3.motor-pos-cmd => stepgen.3.position-cmd
net apos-fb stepgen.3.position-fb => axis.3.motor-pos-fb
net astep <= stepgen.3.step
net adir <= stepgen.3.dir
net aenable axis.3.amp-enable-out => stepgen.3.enable
net all-home => axis.3.home-sw-in

Notice these two lines:

MIN_LIMIT = -3600.0
MAX_LIMIT = 0.001

I found that if I change that to:

MIN_LIMIT = -360.0
MAX_LIMIT = 0.001

the respones return to normal, could problem be the crunching of large numbers perhaps?

Problem solved by re-installation.
Thanks