But math?

I checked the filament with the calipers.  It measures between 1.73 and 1.76.

As far as the extrusion width and nozzle width:

I have no idea what the nozzle width actually does.  I tried changing that number anywhere from .25 mm to .5 mm to see what would happen and as far as I can tell nothing changes (with the exception of the spacing of the filaments on the first layer after a raft).  But even that change doesn't affect the fill percentage because the strands will just get thinner/wider to compensate.

I also tried changing the extrusion width from .2 to .5 mm.  At .2, it just turned wispy and useless.  At .5 it is nice a nice and strong filament, but there are obvious gaps between the individual strands.

I tried the .35 and .42 settings you suggested and the problem still remains.

The only thing I can think of is that my filament has absorbed some water over the last year and is actually measuring thicker than it is when you heat it/drive the water out.

But the inevitable problem is the mismatch between the single wall thickness, and the proper infill of solid layers.  If I adjust filament diameter, extrusion multiplier, etc. in order to get a good infill, then it will inevitably lead to thicker than requested perimeters.

Also, other things to add.  I have ruled out the following:

It isn't print speed.  I changed perimeter and solid infill to both be low (30 mm/s) and the problem remains

It isn't nozzle temp.  I tried from 190 to 220 without any effect (Using ABS)

Perhaps I was unclear.

When I say that nozzle width doesn't do anything, I mean it seems to be a variable which no equations use.  I can put whatever I want in there, but when I run slic3r, it doesn't make any difference.  The Gcode is the exact same, and when printed, to two models look the exact same.  That variable doesn't seem to affect slicing, or printing in any way.

Now obviously if I had a different nozzle (I.E. I put in a .4 mm replacement instead of a .35 mm) then it would have an impact on print quality.  But as long as I don't change the physical nozzle, just the number in slic3r, it seems to have no affect.

The easiest way I found is to open your reptier host (I assume your using that one), then click config -> firmware eeprom settings (You will need to connect to your printer in order to do this.)

From there, change the steps per mm for your E axis to whatever it is currently * whatever your calibration multiplier came back as.  For me, that means changing it to 110 to account for the 25% over extrusion.  I also had to change my Y axis from 88 to 89 steps in order to get my prints to come out square, but I don't know if that was just me.

I still have issues with getting a full infill without over extruding, but I have just resolved to live with a slightly underfilled infill, and a slightly overfill perimeter for now.  I am currently looking at other slicers besides Slic3r to see if I can get better results.  I am also looking for something that does overhangs/supports better as Slic3r just makes supports that can't be easily removed from curved undersides.

Ahh, yes the peeling.

The lifting you saw on your black cube is due to a problem where the layers are deposited warm, and then cool.  As they cool, it shrinks.  This causes the top of the part to want to shrink relative to the bottom part, which makes it want to curl upwards.  There are a couple things you can do about this:

1. Better bed adhesion.  If it sticks to the bed, it wont peel up.  Try turning your Z stop screw a bit counter clockwise to make the layer squish more.  Or you could also increase the first layer extrusion width on your advanced settings in slicer to glob down a thicker base.  You could also try some adhesives.  I am using hair spray to excellent (almost too good) results.  Although, if you are going to use adhesives, you might want to get some glass plates for ease of cleaning.  Just search for glass plates or glass bed on here.

2.  Lower your print head temp.  Lower temp = less shrinking, and also better bridging.  I use 205 C for my first layer, and then 190C for the rest.  High temp gets good sticking, but low temp gives better results.

3.  Go slow.  Give your previous layer time to solidify before you lay down the next.  The filament -> cooling tab in slic3r is good for this.

As for your bridging:

1. Lower print temp

2. A fan is a good idea if your going to be doing alot of bridging (I am installing one this weekend)

3. Faster bridging speed

4. Mess with your bridging flow rate.

And just beware that calibration can take time.

How do you setup the first layer 205? and then 190?

Sounds like your extruder is not quite calibrated yet and you're underextruding. I'd recommend the following:

(1) Start with the extruder steps-per-mm calibration here: http://solidoodletips.wordpress.com/201 … libration/

(2) Follow on to do a wall-thickness calibration, instructions here. Make sure your target wall thickness and the wall thickness setting in slic3r (under the advanced section) are the same (if your machine is fairly new note that you probably want to target 0.48mm instead of 0.42mm to account for the slightly larger bore nozzle in newer machines): http://solidoodletips.wordpress.com/201 … flow-rate/

(3) Readjust your z-stop screw and first layer wall thickness setting (again in slic3r advanced section) as required to get the first layer to adhere well again.