Problems getting infills <60% to stick together

Hey guys,

i am having trouble with infill settings less than 60% (rectilinear).

While prints with 60% infill create a beautiful looking lattice, As soon as I go to 50%, though, it looks like the filament "curls up" instead of sticking to the layer below. All other parameters are the same.
Here is a collection of photos of both tries, you can easily tell which is which.

[www.dropbox.com]

Some data:
- 0.35 nozzle treated as 0.25 in firmware
- 70 mm/s infill speed
- PLA @185 C
- 0.1mm layer height, although I have seen it just the same with 0.2mm layers

Has someone else experienced this? And found a solution? I will be thankful for any hints, as low infills will really help me save time with my prints.
Thanks!

Edited 1 time(s). Last edit at 06/04/2013 11:14AM by formatc1702.

You're printing very fast, slow it down, and this:
"- 0.35 nozzle treated as 0.25 in firmware"

is a major error of you and should be set to realistic values. Calibrate first

formatc1702 Wrote:
-------------------------------------------------------
> - 0.35 nozzle treated as 0.25 in firmware

What does this mean? The firmware has nothing to do with the nozzle size and has absolutely no settings for the it.

---

FFF Settings Calculator	Gcode post processors	Geometric Object Deposition Tool Blog
Tantillus.org	Mini Printable Lathe	How NOT to install a Pololu driver

I'm sorry, I mean I use that setting for Slic3r, not firmware. Using 0.35 was giving me visible gaps between extrusions. The extruder's steps/mm and filament diameter are correct and no increase in flow rate seemed to help. I have virtually eliminated backlash as well. Changing the nozzle size did wonders, everything else works fine.

What intrigues me is that the quality drops so quickly when changing the infill by only 10% and I am hoping to find another cause.

Edited 2 time(s). Last edit at 06/05/2013 03:30AM by formatc1702.

I think Slic3rs default widths based on the nozzle diameter are incorrect and almost opposite of what is correct. Setting it as a smaller diameter always worked for me (if it is still that way I use Kisslicer now). If you are willing to set the widths manually in the advanced section you can try my calculator to determine the correct settings for your nozzle. See my signature for the link to the calculator.

---

FFF Settings Calculator	Gcode post processors	Geometric Object Deposition Tool Blog
Tantillus.org	Mini Printable Lathe	How NOT to install a Pololu driver

Have you tried increasing your extrusion temperature ? 185 seems to be a little low no ?