7I97T joint following error

The issue is this:

[JOINT_0]
CARD = 0
TAB = 0
AXIS = X
MIN_LIMIT = 0
MAX_LIMIT = 30
MAX_VELOCITY = 200
MAX_ACCELERATION = 200
TYPE = LINEAR
SCALE = 40000
ANALOG_SCALE_MAX = 10
ANALOG_MIN_LIMIT = -10
ANALOG_MAX_LIMIT = 10

That sets the PWM scale so you need an error of 20000 inches to
get a full scale (10V) output, or 2 inches to get a mV.

Ideally the PWM scale should be set to the velocity in machine units per second
at 10V. This way, the FF1 term is known to be 1.00



 

That definitely made a huge difference!! What would be a good SCALE number to start out with? or how does one calculate it?

The scale is generally either left in volts (10) or better
set to the machine units per second at 10V

That is, you have a inch machine, so motion calculations
are in inches per second, if you set the PWM scale to
the velocity (in inches per second) you get at 10V,
then  all the PID numbers are scaled in motion units
(inches per second) and FF1 (the most important
PID tuning parameter for velocity mode servos)
is 1.00

So say my servos are 2400 RPM @10V with 2/1 reduction and 5 tpi ball screws, would that be the basic formula used to come up with velocity in IPS?

Basically 4 IPS would be my scale number if I'm understanding you correctly..

Yes, at motor 2400 RPM the ballscrew would turn at 1200 RPM (20 TPS)
and 20 TPS * 0.2 IPT = 4 IPS