Rotary angle does not match

I'm having problem with the rotary gear ratio, I jog the rotary axis (8th axis) E2 to 90 degree but it gives me around 52 degree, How do I correct this?

Thanks.
I had a look at the Machine data and $RAT_MOT_AX[8] is:

$RAT_MOT_AX[8]={N 3119556,D 10000}.
Tweak around the N value, when set N = 185, then jog the rotary axis to 90, it gives 32.5 degree.
then tried $RAT_MOT_AX[8]={N 512.30,D 1}, gives 86 degree.
$RAT_MOT_AX[8]={N 5135.30,D 10}, 88degree~89degree....
Is this method accurate?

Eusty,
It meant to be N5135, D10 not N 5135.30,D 10, .. , I'm aware of the integer.
Browsing through my photo library to see if I can find the rotary image with spec. sticker on it, this is the closest one:

I mentioned about this gear reducer before, it was taken from a KR125 A3 joint, need some info. on this Kuka gear reducer.

Thanks man, really need to get this done so I can test all 8 axes for milling.

Hi sky,
That gear reducer was purchased from a ex kuka Tw technician and he said it is a A3 of KR125 and the MADA for this axis is: $RAT_MOT_AX[8]={N185, D 1} before dis-assembled.
My measuring equipment is this inclinometer, I wouldn't say is an accurate measuring tool but good enough for rough measurement:

The diameter is very close to A3 on KR2210, can't be A4 or A6. I measured it just now:
It is around 323mm Diameter

The servo motor of E2:

While I was tweaking the $RAT_MOT_AX[8] N value when save and exit return to navigator screen, highlight R1---> Program it loads very slow, even when highlighting other folder, then I use crtl + ESC to restart windows...REBOOTING.... after entering KSS on thr right screen where the window shows all axis value in X, Y, Z, E1, E2 all described Invalid value....the numbers appeared after I started jogging -Y, but only A4 rotates no matter I jog X Y Z, so what's going on here?

Quote from eusty

KR125, KRC1 controller

s/n 787483

Code

$RAT_MOT_AX[1]={N -184,D 1}
$RAT_MOT_AX[2]={N -184,D 1}
$RAT_MOT_AX[3]={N -185,D 1}
$RAT_MOT_AX[4]={N 1284,D 11}
$RAT_MOT_AX[5]={N 108,D 1}
$RAT_MOT_AX[6]={N -1575,D 22}

Older version with (I think) TJ gearbox

s/n 724633

Code

$RAT_MOT_AX[1]={N -1904,D 10}
$RAT_MOT_AX[2]={N -1904,D 10}
$RAT_MOT_AX[3]={N 1904,D 10}
$RAT_MOT_AX[4]={N 1284,D 11}
$RAT_MOT_AX[5]={N 108,D 1}
$RAT_MOT_AX[6]={N -1575,D 22}

Thanks Eusty.
$RAT_MOT_AX[3]={N -185,D 1}
$RAT_MOT_AX[3]={N 1904,D 10}
My current N value is $RAT_MOT_AX[8]={N 514,D 1} and it is very near to 90 degree when E2 is jogged to 90.004xx.
I have to jog E2 every time I change the N value to check the inclinometer, how do I run a program that turn E2 only to 90, 180, 270 degree?

Thank you all, will try that tomorrow.

Quote from SkyeFire

However, make sure to always put the axis at 0 before you change $RAT_MOT_AX, otherwise that PTP {E2 90} command will not accurately reflect what the axis is actually doing. Basically, changing $RAT_MOT_AX when the axis is not physically at 0 will throw off your zero position until you re-master.
PTP_REL {E2 90} will generate a purely relative move starting from wherever the axis is when the command is executed, without needing to worry about the axis' absolute position.

I forgot to say when the E2 return to Home position is not actually @ 0 degree, it is 1 degree off, to correct this do I jog E2 to 0 degree then Setup > Master > Dial?

"The motors also have internal gearing, declared in $RAT_MOT_ENC. If you've swapped motors around, that would be an additional factor. KUKA motors generally have a RAT_MOT_ENC of 1/3 or 1/4."
I will try these $RAT_MOT_AX[3]={N -185,D 1} and $RAT_MOT_AX[3]={N 1904,D 10} and see what I get in the inclinometer, if it turns out to be somewhere between 50~70 degree, then does it mean I have to do something with RAT_MOT_ENC?.
Is it correct if I say the N value is equivalent to pulse?, like those in Stepper motor drive where stepper motor turn 1.8 degree per pulse and 360 degree = 200 pulse.