slicer scaling behaviour... wild...

[OBELIKS]

Under Other tab on the Process settings you should have Horizontal size compensation. Change that to 0,7mm
You should be close for the internal diameter.
https://forum.simplify3d.com/viewtopic.php?t=2042

But if you made the model, try increasing the dimensions.

[fma]

That's a huge différence; you may have some over-extrusion?

[OBELIKS]

At first I also thought of over-extrusion, but then also the outside dimension would be bigger, but it's also smaller.
Something is not completely OK here.

[fma]

My bad, I mis-read the outer dimensions!

[c310]

@obeliks

Under Other tab on the Process settings you should have Horizontal size compensation. Change that to 0,7mm

thanks! that is a very strange parameter for me. with test i have figured out that -0.25 mm worked with my 101,08 scale.. however that ratio brought down external size in my particular case i can live with that, but it is very and very strange...

[OBELIKS]

Check X and Y steps/mm just to be sure.

[c310]

slicer i guess is a crap... with settings above radial holes are tight as it should be, central one in loose.... in CAD they are all the same..

[fma]

I'm pretty sure you have a hardware/firmware configuration issue... There is absolutely no reason S3D changes holes dimensions depending where they are on the plate.

[c310]

CAD settings are below. as well as motor settings. printer is delta

M569 P0 S1				; Drive 0 goes forwards
M569 P1 S1				; Drive 1 goes forwards
M569 P2 S1				; Drive 2 goes forwards
M569 P3 S0				; Drive 3 goes forwards (extruder)

M350 X16 Y16 E16 I1    			; Set 16x microstepping with interpolation

M574 X2 Y2 Z2 S1			; set endstop configuration (all endstops at high end, active high)
M666 X0 Y0 Z0				; put your endstop adjustments here, or let auto calibration find them

M665 R102 L288.17 B75 H152		; set delta radius, diagonal rod length, printable radius and homed height
; H152 for standart 
; H142 for volcano

M92 X80 Y80 Z80				; Set axis steps/mm http://prusaprinters.org/calculator/#stepspermmbelt 

M906 X1250 Y1250 Z1250 E700		; Set motor currents (mA) 85% of rated
M906 I30				; Set Idle factor to 30%

M201 X1000 Y1000 Z1000 E120		; Accelerations (mm/s^2)
M203 X20000 Y20000 Z20000 E600		; Maximum speeds (mm/min)
M204 P500 T2000				; Maximum Print and Travel acceleration

[fma]

As @OBELIKS said, re-check M92 values. And as your printer is a delta, re-check the calibration.