Note: the original thread title was "how do i fix overextrusion on infill in orcaslicer?". we've since deduced that's not what's happening. i'm leaving the rest of the op as is so you can follow the process.
So i'm doing a test print for a hot wheels track i'm making for a friend's kid on my snapmaker u1, and i'm hearing scraping noises. when i look at the in-progress print, i see this horribly mangled infill. obviously the nozzle is hitting the previous layer, right? so that's overextrusion, i think. too much material. but i let the print run, thinking maybe ironing will save it. but the surface finish is absolutely awful. all of the bumps and ridges of the infill pattern transfer up through the solid layers. not to mention now there's ringing from the nozzle hitting the bumps, so there's even more bumps. bummer.
also yes i fucked up the overhangs by trying to cheap out on supports. at least that one i know how to fix.
so, how do i deal with this? snapmaker ships a specialized version of orcaslicer (it's called snapmaker orca, it's on github) to deal with the u1s four separate print heads, and as far as i can tell there's no setting in there for infill flow? should i just try to slow everything down? i thought it might be vibration-related so i added a 20kg concrete slab and a thick anti-vibration rubber mat to the setup but nothing changed. i also dried the filament out for six hours. the hygrometer in the snapdryer got down to 12% i think.
i'd hate to not be able to print this for the kid, it's such a cool plaything.
Edit: to clarify, the grey filament is snapmaker matte PLA. the spool has an rfid chip in it so i've not changed any settings, the printer just detects it and sends it to orca.
Edit 2: i've done another test using gyroid infill and a lower flow rate, as recommended in the thread, but the surface finish is all bubbly. i cut a part out to check if the infill was the problem but it looks fine, while the surface is fucked. this is after ironing, by the way.
Edit 3: okay, i've now dried the spool out overnight and made a test disk with tweaked parameters, and i'm still seeing bubbles on top. here i increased the ironing flow from 8% to 20% so the surface is a lot smoother, but the bubbles are still visible. also getting some weird blobs on the side? could be related to the ironing. the middle circle is for a multicolor test but the dot was so small that the filament amount came out to 0.00 grams and the printer didn't really know what to do. it just put in a single dot of (the wrong) filament and avoided the area.
the changed parameters are
- flow ratio: 0.95 -> 1
- nozzle temp: 215C -> 220C
- max volumetric speed: 22mm^3^/s -> 15mm^3^/s
- seam position: nearest -> random
- scarf joint: off -> contour and hole
- ironing flow: 8% -> 20%
- infill: gyroid 15% -> TPMS-D 10%
- infill combination: off -> on, 80%
oh hey this message federated, finally.
so this is snapmaker matte pla, the snapmaker orca fork has a profile built in for it... but it looks weird. the temps are off, the build plate is a little hotter than they specify on their page... i don't know if it's right. i'll do some cubes.
Edit: also, how can you tell the walls are over-extruded?
Okay my new guess is moisture in the filament causing inconsistent extrusion, leading to the bubble on the surface. And also causing over extrusion.
For the walls, your picture is a bit too blurry/low res to really see, but I get the vibe of over extrusion with the small part that's sticking up in the center of the perimeters in the lower right. Also the top of the anchors for the supports looked over extruded, with plastic kinda curling up at the top.
Your new print is now definitely under extruded with those gaps on the top surface.
I think flow rate is not the culprit here. Your bridges on the first print are also extremely suspicious. They should be solid lines, not the blobs you're getting. Something is wrong with the flow of filament out of the nozzle. Could be moisture or temperature or issues with the extruder. It's hard to tell.
you know the weirdest part? i've now seen the exact same surface pattern on two test prints. it's not just that there are bubbles, it's that they are the same size and shape. and that's with different infill patterns; one rectilinear and one gyroid.
i sort of figured the gaps with the lower flow rate were underextrusion. i've already dried out the filament though. first for six hours on low heat in a snapdryer, then into my home-made dry box overnight. the dry box just a plastic bin with a hygrometer, a one-way valve so i can pull some air out with my vacuum, and one of those big-ass reusable desiccant bags for cars. the snapdryer read 10% humidity when i pulled the spool out, and the drybox is at like 11%. is that still too much?
as for temp, the official specs say it's good for 190-230C, and the preset runs it at 215. could that be too cold?
another think i've thought about when looking through the settings is that the preset for matte pla runs very fast. the "generic pla high-speed" preset runs at 18 mm^3^/s, "snapspeed pla" runs at 20, and the matte preset runs at 22.