stepConf and actual running precision issue

fannlow wrote:

by the way, how do I see if its scale for degrees or distance (mm)?

LinuxCNC doesn't even "know" the units. You say move from X = 1 to X = 2 and it gives you SCALE pulses. The units could be degrees, inches, furlongs, angstroms... (and SCALE/10 pulses if you move from 100.2 to 100.3)

It is Stepconf that tries to be clever.

fannlow wrote:

SCALE = 157.480314961
...
SCALE = 157.480314961
FERROR = 1

They are now the same. They weren't in the INI I looked at.

Are you sure that the drives are actually on the same micro step setting?

That all looks OK, except the min and max limits. Is there any reason why you have that set to negative?
The other thing i find disturbing is having a pinion directly mounted on the motor, a few issues with that, but it is possible.
Issues: motor needs a lot of power or it will skip and miss steps, if it has enough power it will vibrate to much again causing it to miss steps mostly at lower speeds as it would resonate. Also asking a motor to move something 0.41mm per step is not efficient.
Again, that can work and it does but there are to many issues with it and getting it to work reliably is quite a challenge .
One more thing, if you have not already read about it, XYZ work normally regarding G0 and G1 feed speeds, ABC are not linear axis so you have avoided them< this is good, UVW axis do not comply to G1 feed speeds so they will tend to move at max speed all the time.
The last part about UVW, i am not sure about, but i remember reading about it lately.

Lets go back,
1.>>>What type of drives? < regarding this, can you please set the timing values at 15.000, 15.000, 20.000,20.000
2.>>>Set the base thread to 100.000
3.>>>You MUST know the drive micro stepping, no guessing there, so in case you can not find them you can follow this procedure, but only after the step No.1
---Set the micro stepping to 1 for all axis, leave the rest as you have it now, do a "test axis" and set velocity to 5 and accel to 30, at the "-+" choose "+" and set the movement to 50mm. Measure how much it moves? from that you can figure out the drive micro stepping as follows:
......if it moves 50mm you are good to move on
......if it moves 25mm you have 1/2 micro stepping so you need to set 2 at the drive micro stepping field in stepconf
......if it moves 12.5mm you have 1/4 so set it at 4..............and so on.
4.>>> Only when you get this right, you can move on to set the speeds and accelerations.
try this and report back.
thank you.

Also when you get your scale figured out run a stepper test on each axis as shown in the manual to make sure you have not exceeded the maximum acceleration or something which may cause lost steps. Do your scale measurements at a slow speed.

JT