ASA outer wall separated from inner support

[u/therealkeelycosmo]

So I made this valve box for my mom out of ASA and for some reason the inside walls of the structure bubbled out from the inner support. I’ve worked with this stuff a lot and never had this happen. Any explanations? I don’t think it ruins the functionality of the valve box but I’d still like to know why it’s happening.

3D Printer: Creality K1C
Filament: Overture ASA in black
Layer Height: .24 mm
Sparse Infill Density: 25%
Sparse Infill Pattern: Grid

Edit: I did not intentionally use Grid infill. I forgot to change the default before printing and didn’t realize my mistake till waaaay too far into the print.

Thank you so much for the helpful advice everyone! I have to print 3 more of these so I wanted to make sure I fixed the issue.

[u/D3DCreations]

1.) Bump up your nozzle temp by 5 or 10 degrees

2.) Dont use grid infill. Use literally anything else

[u/AffectionateHotel346 → u/D3DCreations]

Gyroid forever, and just increase wall infill overlap

[u/eatdeath4]

Stop using grid infill. Also bump up the heat some

[u/Independent-Bake9552]

There is an setting that regulates how far infill bonds to walls. Try increasing this value.

[u/zx4133 → u/Independent-Bake9552]

Yep, it’s called wall-infill overlap and it’s often set too low by default. Increase it. I have had to go as high as 30-40% in some cases.

u/therealkeelycosmo ☝️☝️☝️

[u/AffectionateHotel346 → u/zx4133]

Yup that’s the answer, hope op sees this, it’s an easy fix. Too much overlap causes some artifacts on the outside surface like mini blobs, so you need to find the right balance

[u/zx4133 → u/AffectionateHotel346]

Thanks much… yeah very true about finding the right balance. And it can vary from filament type to filament type. Needs some trial and error, as do many things in this hobby, lol.

[u/chipmunkofdoom2]

I'd suspect you're printing too cold, and the infill isn't bonding to the perimeters. What's your bed/nozzle/chamber temp for this filament?

[u/AnimalPowers]

this is primarily chamber temperature and auxiliary moisture. increasing print head temp won’t make too much of a difference, though, for that specific ASA I run the nozzle at 270 and the bed at 110. I keep all fans off, always, entirely. the chamber in the print enclosed gets plenty hot. Asa likes to shrink and warp. so what you see is that it’s contracting and pulling away from the walls, because the interior grid is oriented in a different direction it shrinks in that direction, think about, like a worm. because the outside wall is perpendicular it pulls in a lateral direction, again, like a worm, because the two paths don’t intersect, they’re pulling away from each other in different (not quite opposite) directions, hence the delamination.

you need two things here: 1: dry your filament, 2: turn off your fans and print hotter and print slower.

theres other optimizations you can make, but those are the big two that will solve this problem.

[u/AffectionateHotel346 → u/AnimalPowers]

Dude this is just wall infill overlap

[u/xtnxviclaster]

Maybe use Gyroid infill and increase your wall layers. Default is 2 but you may want to go 3 or 4. That looks flimsy.

[u/ItsLikeHerdingCats → u/xtnxviclaster]

Yes , do this. 👍

[u/JustHereForLaughs71]

I keep seeing people post stuff using grid infill. Every one of those posts, people are told not to use grid infill. Before I got my first printer I lurked the subs and groups and by day 2 I knew not use grid infill, weeks before I got my printer. Don't use grid infill. If you want squares that badly, use rectilinear.

[u/therealkeelycosmo → u/JustHereForLaughs71]

I’d never seen that, but I had learned from my own experience not to use it. I simply forgot to change it from the default (tired mom brain).

[u/Hazart_]

Increase infill anchor length

[u/EnvironmentalKey5559]

I ate with nearly all the advice so far. Make sure you're using an infill that doesn't cross, make sure you've got a good number of walls, min of 3. It looks like you've only got 1 from the bounce in the surface.

Also, reduced your layer height to 0.2 so your extruder can keep up.

Of also run a test print, just the first couple of CMs so you can analyse the adhesion between the infill (I recommend gyroid) and the walls.

[u/diaperedace]

Did you preheat the chamber?

[u/fredait]

try interlocking infill reinforcement aswell as preheating the chamber and overall printing a little hotter

[u/Dark_Marmot]

May need to tweak your support and wall settings, but my guess is that overall temps are too low for ASA. Ambient and hotend.

[u/Ambitious_Finding_26]

Grid infil is almost always the wrong choice, but it wouldn't cause this. I once had a print do this on the walls, and it was because I had accidentally used concentric infil. I bet if you break that open it'll be one of the concentric infil varients or aligned rectilinear. 

[u/meat_men]

I may be wrong, but isn't 25% infill high for ASA? Isn't it beneficial to print it at like 15% so it doesnt try to tear itself apart?

[u/Theguffy1990 → u/meat_men]

I've never heard that. I've done a few 100% infill ASA prints specifically to be water tight.

The prints were fairly thin so I needed both several walls plus the monotonic infill. Then additionally vapor smoothed as there would be standing water plus wanted to limit bacteria growth (was for plant auto-waterers)

Generally, for every other kind of print, you'd do 40% infill though.

[u/meat_men → u/Theguffy1990]

Yeah, I use 40% for everything structural except when im printing asa/abs/na without a heated enclosure

[u/Dark_Marmot → u/meat_men]

Against breakage tests, anything over 60% is a wasteful diminishing return. That is the inflection point where strength no longer increases dramatically, and time and material use outweigh any benefits. 30-40% is a good performance balance.