Simplify3D User Forum

So where's the difference to what i wrote?

I'll say it again..... there is actually no underextrusion. The only change is the height of the nozzle!!! Exactly the same amount of plastic is extruded.

dkightley wrote: I'll say it again..... there is actually no underextrusion. The only change is the height of the nozzle!!! Exactly the same amount of plastic is extruded.

I never said there was a visible indication of underextrusion. I said I'm not sure if the preview shows underextrusion at all.
(Do lines get thinner if playing around with the extrusion mutliplier? I've never tried).

parallyze wrote:I'm not sure if the g code preview shows underextrusion.

So... where's the difference between:

parallyze wrote: As you can see the preview always draws preview lines with a certain "thickness". I'd say it's just the way it is shown which may lead to think it's underextrusion. But if a layer is only 0,04mm (like it's the case with 20%) the preview somehow has to display this properly - hence the first layer
is drawn a bit lower.

and

dkightley wrote: As a first layer height under 100% results in the amount of plastic being extruded not being reduced, the simulation draws the layer height as the same as if it was 100%, but...and an important but...the simulated layer is drawn at a lower height so that the top is at the reduced height. The layer is consequently drawn part above the bed....and part below the bed.

Guys, I think I figured out what happens. The calibration procedure of my printer requires to apply much higher pressure to the calibration card to get a good offset ( In comparison with different printers I worked with before). So my nozzle was obviously too high, what caused separation of the first layer.
When i tried to regulate it using "First layer height " I could not make it close enough even saying that first layer height should be 80%-90% lower than it should be. But I have no idea why it start to print good when you make it the nozzle higher (like 200%). Some ideas?

Btw, the g-code preview doesn't display the under extrusion. You can see it if you would make extrusion multiplier very small, and the g-code preview wont change.