extrusion multiplier vs. extrusion override... not the same?

[Lorcoft]

I have a Makerfarm 12"x12"; and I've been able to get some really good resulting prints from it; but there is still an issue or 2.

When I set the extrusion multiplier to 1 and the extrusion override to 100%, I get under extrusion. I can fix this by setting the over ride to 125%, but the change doesn't happen immediately, and it affects the first layer or so. I've calibrated the extruder and that doesn't seem to be the issue.

I tried changing the value for the extrusion multiplier but can't seem to find the correct value to get the same results while leaving the over ride at 100%

So, I have 2 questions...

if I have a extrusion multiplier of 1.00 and an over ride of 125%, does anyone know what the inverse would be to get the same extrusion? or

Is there a gcode command I can put into the start script to set the over ride to 125% ?

any advice would be very helpful;

Lorcoft.

[JoeJ]

Both settings have an identical affect. So if you had 125% for the extrusion override, that's the same as 1.25 for the extrusion multiplier with the extrusion override in the Machine Control Panel set back to 100%.

[Lorcoft]

That is what I thought as well, but the printed results come out differently. With only those 2 setting changed.

If I set the extrusion multiplier any higher than 1.2, the results look mushy...

I'll keep playing with it and see what's what.

[wfcook]

I could be wrong, but think extrusion override applies to ALL extruder moves, including retractions, etc. whereass the extrusion multiplier only applies to the actual amount of filament being extruded. If I am right about that. then it could be that you are seeing the differences due to nozzle pressure.

[Lorcoft]

Ah, now that makes sense, because one of the things I did adjust was the retraction. It seems to be working.