ianrossg

So nothing's changed besides adjusting the feeder slightly tighter after realizing there was a good chance the under-extrusion was partially caused by a feeder that was easily put into a slip state (I put my finger up to the feeder input, pressed against the material to get a feel for the feed rate and retraction rate and felt slippage from the extra resistance). After running a print I'm unfortunately back to determining what's going on within my Cura configuration profiles. because I'm still seeing the same issue. ha, yeah so that was yesterdays fiasco. Haven't been able to master the atomic pull as I usually just get what I assume to be a good pull and instead I come to find the material breaking at the entrance to the heater block. So anyway, I ended up pulling everything apart, heating the block up, and cleaning it out the old fashion way, 150psi air through it for the bulk material, and I finished up with a makeshift pipe cleaner/solder wicker (14Ga wire stripped and twisted). I am now fairly certain feed resistance isn't the issue. I'm still seeing under-extrusion on the left inner walls while the inner right walls have some slight over-extrusion, or at least on the flat surface, the curved surface is perfect. What I'm wondering is if this may have something to do with acceleration or retraction settings. The layers start with the infill on the left side, then there is a retraction and combing travel across the skin where the under and over-extrusion occurs. Once the infill finishes there is a similar travel back to the left center support where the skin starts its extrusion (or lack of). Come to think of it, the infill might be a dead giveaway. My issue is that I've got some ooze issues with the 0.8mm nozzle, so I've got (whats in my mind is) a high retraction of 6.25mm. I guess I could get frisky with the print temp and drop it down, but I feel like that'll lead to other issues.

Yeah, I've already got them on order now that I've been reading the horror stories people have gone through with them and how simple a fix it is to swap out. To clarify, the issue is still occurring, and in running some older parts I'm seeing that the issue isn't occurring on them. So my guess is something within my print profiles has become problematic with the Cura 5.* slicer. I'm going to try running a print with the Cura defaults and see if by chance that will provide some clues.

I've been printing solely in ABS for the past 6+ years on this machine and never had an issue with under-extrusion, if anything the opposite for a while until I turned the down flow rate from the default 107% for ABS to 100%. My parts require ABS or ASA for high-heat applications. Back when I started working with the ABS ASA wasn't readily available or popular yet and PETG has remained off my radar until recently as well. Unfortunately ABS sucks to print, but I've learned to simply grit my teeth, embrace the smell, and yell at anyone who leaves a building door open which might upset the print chamber temperature. I originally didn't want to get into specific temps in the original post because I've changed materials, but I was printing at 260°C (the upper limit for the printhead) with the previous material and that worked great for years. This new material (Kodak) I've dropped way down to 240°C and am seeing similar flow characteristics (slightly more warping at the same 105°C bed-temp, but that's another issue). The outer wall is set to print at 75.0 mm/s on a 0.8mm nozzle. I went ahead and pulled the printhead apart, cleaned the hot end very thoroughly, but found the isolator (original) to have some slight charring on the end. Despite this not being the recommended fix, I used a hole deburring tool and cleaned up the edge to remove any charred burrs and took some measurements to ensure I was within spec (measured 3.05mm ±0.05mm ID on both ends). Since going through the entirety of the printhead (less intimidating than I thought) I'm seeing identical prints (turned the flow up to 102% not that that's enough to see anything).

I didn't want to take over your thread, but I'm seeing similar issues (more prominent) on a Ulti 2+ Ext. What material are you printing with? Nozzle diameter? Here's the thread I created.

Having an issue on a Ultimaker 2+ Ext running ABS. The photographed print may amplify the issue due to the scale of the object requiring it to be printed on a 45° angle. I am seeing under-extrusion on the left inner side (very extreme on the convex curve) and over extrusion on the right inner side. On the back side (relative to the Cura screenshot) all but the most recent print (can be identified as it's taller and shinier) (new material manufacturer) have a very course texture, although nothing necessarily visible besides some little nub lines that can be easily scraped off (as if there were a Z seam which there isn't). I've attempted adjusting flow and print speed rates, fan speeds, retraction length and speed, printhead temp and even a new material manufacturer. Throughout my testing I've cleaned all the components, gave the nozzle a acetone bath, and polished the printhead brass to reduce and potential for material sticking. I have a suspicion it's related to the Cura 5+ slicing methods exaggerating materials related setting, but haven't tested out slicing in 4.* yet. The issues seem fairly repeatable when running the same print and in prints that are positioned with straight lines moving primarily on the X or Y axis the issues can still be identified on the curves. Any advice would be greatly appreciated as I've run through over 1kg of material on this and have made no significant progress to date besides changing material manufacturers which unfortunately isn't a great solution. SL+30deg.R1.4.3mf