and Carl, the formula is in that document i shared, as is the formula for calibrating the extrusion rate.

oh, I was thinking it was integer only.  D'oh!

There is an actual formula for doing this so you don't have to guess.

New Steps/mm = (Old/Current steps/mm) x [100 / (measured distance filament traveled)]

You can also use,

(expected length* x current steps per mm) / actual length = new steps per mm

This is the one I use.

I actually made a spread sheet where I just plug in the required values and it spits out the new setting.

That PDF is good.  Thank you.

I set up as shown in the picture, and measured how far the filament moved after extruding 100mm.

99.23mm
so if anything it's a little short.

In Machine settings in the IIIP Cura, the E steps is set to 415

In the start code, I have E steps at 417, from the previous time I checked this.

M501 returned this -
> M501
< echo:Stored settings retrieved
< echo:Steps per unit:
< echo:  M92 X80.04 Y80.04 Z400.48 E94.30
< echo:Maximum feedrates (mm/s):
< echo:  M203 X300.00 Y300.00 Z5.00 E25.00
< echo:Maximum Acceleration (mm/s2):
< echo:  M201 X3000 Y3000 Z100 E500
< echo:Acceleration: S=acceleration, T=retract acceleration
< echo:  M204 S800.00 T800.00
< echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum XY jerk (mm/s),  Z=maximum Z jerk (mm/s),  E=maximum E jerk (mm/s)
< echo:  M205 S0.00 T0.00 B20000 X10.00 Z0.40 E1.00
< echo:Home offset (mm):
< echo:  M206 X0.00 Y0.00 Z-1.90
< echo:PID settings:
< echo:   M301 P9.12 I0.41 D50.98

So I send M92 E417 in the command window.
Re run the test...

I get 100.45mm

I set M92 E416

And measure 99mm.

Go back to 417, measure 100.37mm

In case you are not aware, you can and should use decimal values like 417.6285. I have had to go out to 4 decimals sometimes to get an axis and the extruder truly dialed in.

I set up as shown in the picture, and measured how far the filament moved after extruding 100mm.

99.23mm
so if anything it's a little short.

In Machine settings in the IIIP Cura, the E steps is set to 415

In the start code, I have E steps at 417, from the previous time I checked this.

M501 returned this -
> M501
< echo:Stored settings retrieved
< echo:Steps per unit:
< echo:  M92 X80.04 Y80.04 Z400.48 E94.30
< echo:Maximum feedrates (mm/s):
< echo:  M203 X300.00 Y300.00 Z5.00 E25.00
< echo:Maximum Acceleration (mm/s2):
< echo:  M201 X3000 Y3000 Z100 E500
< echo:Acceleration: S=acceleration, T=retract acceleration
< echo:  M204 S800.00 T800.00
< echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum XY jerk (mm/s),  Z=maximum Z jerk (mm/s),  E=maximum E jerk (mm/s)
< echo:  M205 S0.00 T0.00 B20000 X10.00 Z0.40 E1.00
< echo:Home offset (mm):
< echo:  M206 X0.00 Y0.00 Z-1.90
< echo:PID settings:
< echo:   M301 P9.12 I0.41 D50.98

So I send M92 E417 in the command window.
Re run the test...

I get 100.45mm

I set M92 E416

And measure 99mm.

Go back to 417, measure 100.37mm

Now the outer edges are kind of blobby.  Looks like over extruding a bit, I think.

don't "think" it is, verify it!

there are very specific steps to take to properly calibrate things.

please see the attached...

and keep in mind that every spool WILL be different, and should be calibrated properly at the beginning of use.
Even 2 spools of the same brand, same color WILL vary in average diameter.

Made around 20 measurements over 10 feet of filament.

15 at 1.7mm
2  at 1.727mm
3 at 1.676mm

Average = 1.669mm

Then that would be the number you would use for filament diameter in your slicer and this will need to be confirmed and changed when needed on every spool you load.

15 at 1.7mm
2  at 1.727mm
3 at 1.676mm

Average = 1.669mm

Ok, I wasn't clear, the nozzle is the 0.4mm one that came with he printer. The setting in IIIP Cura is [and always has been] set to 0.4mm.

That is the information i was looking for.

and carl - never say never.. it does not happen very often, but it does happen that the average does work out to 1.75 - I have a couple spools (out of roughly 50) that are set to 1.75 average diameter.

Ok, I wasn't clear, the nozzle is the 0.4mm one that came with he printer.  The setting in IIIP Cura is [and always has been] set to 0.4mm.

Cool and what is your filament diameter set for in Cura? Like I said it should not be 1.75. It should be an average of about ten measurement taken over several meters of the filament and it is never 1.75. Even 1.74 or 1.76 makes a big difference in the end results.

I use Cura and nozzle size is set by the user in the main machine setting. The filament diameter also needs to be set as well and is not 1.75 ever. Yes that tiny little bit makes a major difference in the prints and how the slicer sets flow volume.

yes, and he needs to verify that it is set correctly.

just saying the stock nozzle is a 0.4 means nothing.. it NEEDS to be set correctly within the program.