Would you agree this is an infill issue? Pic included

[TTVert]

Basically I accidentally printed a fairly large area (160mm square) with 10% infill. I usually use 20% and never have pillowing but on this one I am. I increased it back to 20% and it still looked ugly although the top layer looked a bit better obviously. I print 4 top/bottom layers usually so perhaps this is hidden but I don't recall seeing this on any of my other prints w/ PLA. Granted most don't have the large flat footprint of this one either. I'm using a filament I've not used in years so perhaps that's part of it but I have the extruder at 210, bed at 40 on my maker select 2. Feed rate is 60mm/sec in this area, print cooling fan was spinning 100% PWM. Any input would be appreciated. 20% infill

[fred_dot_u]

At first glance, that looks like overextrusion, but your comment about unused filament makes me wonder if you have moisture in your filament.

If you have a food dehydrator, run the spool in that for a day or so and make another test print. If you don't, you can heat it in a low heat oven, but there are many photos of people who don't manage the temperatures well and melt the entire spool!

[TTVert]

At first glance, that looks like overextrusion, but your comment about unused filament makes me wonder if you have moisture in your filament.

If you have a food dehydrator, run the spool in that for a day or so and make another test print. If you don't, you can heat it in a low heat oven, but there are many photos of people who don't manage the temperatures well and melt the entire spool!

Any layer smaller than this is ok. In fact by the time i got to the top layer of this (4th layer) it looked perfect. If it was an over-extrusion problem I would assume it would always occur no?

Thanks
Dave

[fred_dot_u]

The inconsistency would mean the moisture idea isn't valid. It's really difficult to tell from the photo and the limitations of the information available.

[TTVert]

What other info can I provide you that may be helpful? Sorry about that pic I tried to grab it before the extruder was out of the way. Good point in the moisture not being the issue did to the inconsistent nature of the issue. I'm fairly certain it's the 20% infill but I don't really recall this issue before with larger flat surface.

Dave

[fred_dot_u]

If you have other filament with which to try, that would be another point of information. 60 mm per second is a pretty good speed, but what happens if you drop it to 40 mm per second? It appears in the photo that you are using a raft, is that correct? Do you print without a raft?

[curious aardvark]

think you've pretty m uch answered your own question.

At a speed as slow as 60mm/s yeah infill squares that size are going to make a difference.

Never heard it called 'pillowing' before - but that's definitely down to the size and shape of the infill.

try using tringular infill.
At the same % infill it will drastically reduce the 'pillowing' as the areas being bridged change from small to medium, with tyhe square infill it's always bridging a large gap.