Having a little trouble getting my X direction to move the correct distance.

Having a little trouble getting my X direction to move the correct distance.
Using the G91 X390 and expecting 390mm but only getting 370. X-390 is also short
Using G91 Y390 is spot on both X and -
I have Nema 23s and GT3 belts with 20 tooth sprockets.

The configuration is the same for X and Y

[yam] y axis mode 1 [standard]
[yvm] y velocity maximum 15000 mm/min
[yfr] y feedrate maximum 16000 mm/min
[ytn] y travel minimum 0.000 mm
[ytm] y travel maximum 760.000 mm
[yjm] y jerk maximum 5000 mm/min^3 * 1 million
[yjh] y jerk homing 1000 mm/min^3 * 1 million
[yjd] y junction deviation 0.0100 mm (larger is faster)
[ysn] y switch min 1 [0=off,1=homing,2=limit,3=limit+homing]
[ysx] y switch max 0 [0=off,1=homing,2=limit,3=limit+homing]
[ysv] y search velocity 3000 mm/min
[ylv] y latch velocity 100 mm/min
[ylb] y latch backoff 20.000 mm
[yzb] y zero backoff 3.000 mm
tinyg [mm] ok>
$x
[xam] x axis mode 1 [standard]
[xvm] x velocity maximum 15000 mm/min
[xfr] x feedrate maximum 16000 mm/min
[xtn] x travel minimum 0.000 mm
[xtm] x travel maximum 570.000 mm
[xjm] x jerk maximum 5000 mm/min^3 * 1 million
[xjh] x jerk homing 1000 mm/min^3 * 1 million
[xjd] x junction deviation 0.0100 mm (larger is faster)
[xsn] x switch min 1 [0=off,1=homing,2=limit,3=limit+homing]
[xsx] x switch max 0 [0=off,1=homing,2=limit,3=limit+homing]
[xsv] x search velocity 3000 mm/min
[xlv] x latch velocity 100 mm/min
[xlb] x latch backoff 20.000 mm
[xzb] x zero backoff 3.000 mm
tinyg [mm] ok> city 100 mm/min
[xlb] x latch backoff 20.000 mm
[xzb] x zero backoff 3.000 mm

[2ma] m2 map to axis 0 [0=X,1=Y,2=Z…]
[2sa] m2 step angle 1.800 deg
[2tr] m2 travel per revolution 60.0000 mm
[2mi] m2 microsteps 8 [1,2,4,8]
[2po] m2 polarity 0 [0=normal,1=reverse]
[2pm] m2 power management 1 [0=disabled,1=always on,2=in cycle,3=when moving]
[3ma] m3 map to axis 1 [0=X,1=Y,2=Z…]
[3sa] m3 step angle 1.800 deg
[3tr] m3 travel per revolution 60.0000 mm
[3mi] m3 microsteps 8 [1,2,4,8]
[3po] m3 polarity 0 [0=normal,1=reverse]
[3pm] m3 power management 1 [0=disabled,1=always on,2=in cycle,3=when moving]

All help, suggestions appreciated.

Are your pulley set screws tight and belt tension tight?

Does changing $2tr to 57mm ( which is 370/390*60) solve it?
That is a fairly large error.

Carl, thanks for the reply.

The pulley was tight and the belt tension is good. Things were a little different this morning. The motor moved and stopped and moved some more, then stopped completely.

When trying to move the X axis by hand there was no resistance.

Disconnected the motor and shorted all leads together and the motor turned freely. Shorting pairs had no effect as well.

It appears I have a bad stepper motor.

I have nema 23’s 179 ounce. Since I am going to buy some motors is it worthwhile to up the ounces or stay with the 179 ounce?

Appreciate the help!

When I first upgraded my ShapeOKO, I bought three of these for X and Y https://www.omc-stepperonline.com/hybrid-stepper-motor/nema-23-bipolar-18deg-24nm-340ozin-18a-495v-57x57x104mm-4-wires-23hs41-1804s.html
A lot of torque per Amp. Have worked well for me