Strange infill separation problem after pretty good first layer
Seeing this issue trying to print a v-chonk base. First layer isn’t flawless but looks pretty ok at least to me. Second layer even starts ok…but then at some point midway through that second layer the lines just start lifting up and separating from each other.
Second time this has happened. First time it happened I figured I’d up my extrusion multiplier to make sure enough plastic was going down. I also went ahead and dehydrated the filament for about 7 hours at 60. Unfortunately those changes didn’t do a thing. VC3.1, Polymaker ABS, 100 on the bed and 260 on the nozzle. 1.0 extrusion multiplier (was 0.92 on my first attempt). I’m struggling to understand what sort of issue would cause this kind of behavior. Can anyone who’s seen behavior like this before ELI5 a plausible explanation of what might be happening here?
Second time this has happened. First time it happened I figured I’d up my extrusion multiplier to make sure enough plastic was going down. I also went ahead and dehydrated the filament for about 7 hours at 60. Unfortunately those changes didn’t do a thing. VC3.1, Polymaker ABS, 100 on the bed and 260 on the nozzle. 1.0 extrusion multiplier (was 0.92 on my first attempt). I’m struggling to understand what sort of issue would cause this kind of behavior. Can anyone who’s seen behavior like this before ELI5 a plausible explanation of what might be happening here?
12 Replies
Do other prints come out fine? Also, do you get the impression that the nozzle was clogged when the lines started to lift?
One suspicion I have is that the quality of the first layer is the result of both the z-offset and the flow rate. That means if your z-offset is too high you can still end up with a perfect first layer if your flow rate is also too high. For example in an extreme case where your nozzle is at 0.4mm instead of 0.2mm for the first layer you could still get a perfect first layer with a flow rate of 200%.
The problem starts when you get to the second layer. At that point you are trying to squeeze 0.4mm worth of material into a 0.2mm layer. Especially on larger prints that will eventually end up clogging your nozzle. If that is the case you should also be able to hear your extruder skipping steps and at that point there will no longer be enough filament coming out of the nozzle, resulting in the separated lines.
Thanks for the response! I honestly haven’t printed a single part that’s this big on it in a long long time, but no other “normal” sized prints I haven’t seen this issue with. I did try slicing it at 0.3 rather than the 0.2 I usually use however. I also don’t see any signs of clogging either when it’s happening…the extruder is definitely not skipping.
I think I’m going to try playing with the line width and see if putting down just a little more plastic will help those line edges adhere to each other better…at least that’s where my head is currently at.
I don't know what that is, but when i printed the vchonk base on my 400mm vcore 3.1 with polymaker galaxy black abs I used .89 extrusion (which is my normal extrusion) 100c bed and 240 hotend. I think I printed at 100mm/s speed. I got something like that on my top layer but that was because my part was shrinking as it printed the top layers of the base.
As a side piece of advice, use some sort of bed ahesive and after your printer has put down a few layers use binder clips to hold your flexplate to the bed. I used a lot of magigoo and my print stayed stuck to the build plate but the curl was strong enough to pull the build plate off the magnet sheet.
Yeah appreciate the advice - I had the same issue with my third test print to make sure things were working before I tried a fresh roll. I’m not entirely sure what the issue was, but for sake of completeness this issue seems to have resolved itself for me after releveling and increasing my line widths a smidge. Thanks all!!
Everyone with vcore 4s what temps are you printing pla at I can't get a decent print under 240°c
I have the same issue but not so big holes but still holes
But also on small prints
I also have to run PLA at 240, even that high i have to limit flowrate to 20 or I get gaps in solid infill. Pretty disappointing, using 0.5 West3d TC nozzles
What flowrate do you use ?
20 - any higher and I have problems
Are you using hardened nozzles ?
West3D Undertaker - Its Tungsten Carbide. Same thermal conductivity as brass
Ah okay
Crazy I use 240 degrees for abs
And I use silicon carbide