hello all
Ok here is the deal:
3d router running a recent ver of wincnc on xp desktop
New gecko G201 step motor drive, newer oriental motor PK299-F4.5A, couplings are all good
Y axis occasionally stalls (or binds?) and results in lost steps

Problem would manifest itself occasionally before replacing hardware, with the new equipment it seems even more frequent.

This problem is intermittent during cuts, but can easily be induced by fast transits. does not appear to be a mechanical issue when turning by hand with machine off the action is smooth.

I swapped the inputs on X and Y drives and the problem does not seem to repeat itself on either axis

Thanks in advance for help
the following is the wincnc.ini file which I assume may need some tweaking:

[Timer Card Settings]
timertype=7200
steppulse=p5d5
g09=s12
maxstepv=50000

[Axis Settings]
axischar=XYZ

[Table Size for Viewer]
table=x0 y0 w73 h140 b2

[Velocity Groups]
vgroup=fxy
vgroup=xy
vgroup=z

[X Axis]
axisspec=p0 s0 d0 r3065 a650 f500 o1 e1 k1
axisvel=r400 f125 s20 m100 h500 c5
axislo=p3 b0

[Y Axis]
axisspec=p0 s1 d1 r3425 a650 f500 o1 e1 k2
axisvel=r400 f125 s20 m100 h500 c5
axislo=p3 b2

[Z Axis]
axisspec=p0 s2 d2 r9985.69 a300 f200 o1 e1 k3
axisvel=r80 f100 s10 m25 h100 c5
axislo=p3b4
axishi=p3b5

[Arc Settings]
arc_err=.01
arctype=t1
autoarcfeed=f40

[Soft Limits]
lolim=x0 y0
hilim=x73 y140 z6
lobound=z-6
softlim=1

[Aux]
auxin=c1p2b6o1d20
enab=c1m"Emergency Stop"

[auxout=c1p7b7o1s1e1

[Abort Cushions]
lim_cnt=10
esc_step=1000
lim_step=250
lim_mode=1

[G28 Settings]
g28move=z-.125 r.125 f50 m1
g28move=x.35 y.25 r.5 f100 m1

[Keypad Settings]
Keypad=c1b9600p2
Keypaddir=c:\wincnc\jobs

[Data Directory and Search Wildcard]
filetype=*.TAP