First layer clogging
I have been suffering from my nozzle being clogged (printing PLA) for weeks and tried everything I can think of. I have the z-offset correct, but partway through the first layer the extruder starts clicking and I can see it's clogged.
Before I went back to recalibrating everything it would get a few layers up and then clog.
I've remeasured the bed mesh, recalibrated flow, reduced retraction down to 0.5 and speeds to 30mm/s. First layer print speed is now slower than my Prusa Mini. Tried tight extruder idler tension, loose idler tension. Increased temp to 220, but still click click click. š¢
The nozzle is usually quite easy to clear, although the Orbiter makes it really annoying to yank the filament out.
Does anyone have any ideas on what I'm doing wrong? Should I just go hotter and hotter? I don't feel like I'm going fast enough to go crazy at 21 mm/s where it clogged in the attached picture.
V-Core 3.0 500, EVA 3.0 platform, E3D V6 hotend, 0.6mm CHD nozzle, Orbiter 2.0 extruder, BLTouch, Prima textured PEI sheet.
18 Replies
sensitive-blueā¢11mo ago
In moments of desperation, desparete measures sometimes work. I seem to have fixed this with the following:
Going back down to 215C
Raising the nozzle by 0.2mm
Increasing the flow for the first layer by 1.2x,
Putting the speeds of everything back up to 70-100mm/s
Slowing down support material to 60mm/s
Using a pressure equaliser of 2 in PrusaSlicer for both positive and negative slopes
I'm unsure which of those actually fixed anything, but my guess is a combination of slowing down the support material speed, increasing the z-offset and then adjusting for that with a higher first layer flow rate.
my bet would simply be raising the nozzle. too close and hte material really can't flow as desired.
sensitive-blueā¢11mo ago
yes probably, although earlier this print always failed when it was mostly printing support material, so maybe six of one, half a dozen of the other
I agree with ptegler. Almost always when I get extruder skipping on the first layer it is because I am too close to the bed. One way to test this theory is to raise the first level z height way up and even though it will not stick, see if you get skipping.
sensitive-blueā¢11mo ago
Now my problem is the top layer š¦
sensitive-blueā¢11mo ago
I got extruder skipping about layer 10 a bunch of times so I lowered the flow a little, abandoned hope of variable layer height (0.15-0.35) and got it to the top layer, where it gets part of the way with the infill (hilbert curve) and then clogs there. It's done that twice now.
sensitive-blueā¢11mo ago
Tried printing faster and it got further but still clogged, so probably the extra speed didnt help.
same here.... variable layer height seems to cause me more problems than it solves aesthetically.
when you say it's 'clogging' (with PLA?) are you saying you have to clear the nozzle? before you can continue properly? That's telling me you're getting something else going down the filament path causing as problem. It's possible you have particles of ptfe tube, or something being left on the surface of the PLA filament can accumulate at the nozzle, and are above the temp of the PLA melting point, thus creating a clog.
sensitive-blueā¢11mo ago
The extruder starts skipping and then grinds the filament, and if I catch it straight after I can't push filament through the nozzle, but if I heat it to say 280C and wait a minute I can pull it out ok, and reloading it is fine š¤·āāļø (yes, PLA)
Part of me thinks this feels like heat creep, but then there aren't many retractions and reducing the retraction distance down to 0.5mm hasn't helped
Are you sure it's not an issue with the the path from spool to extruder? (too much 'pull' required) What i.d. is your tube from spool to extruder? Often the semi-standard 2mm id can cause a lot of issues.
I'd say exactly that : check your filament path.
sensitive-blueā¢11mo ago
What ID would you recommend? It is just standard 2mm ID I think.
2.5mm. the typical 2mm x 4mm stuff can easily get pinched down at the connectors. even the slightest kink will reduce the id enough to create drag. Even at .34mm that isn't a lot of slack filament to tube diam. The 3mm x 4mm stuff is simply too thin and will snap on you
sensitive-blueā¢11mo ago
I'll try that, thank you!
just pull your tube out of the extruder, and see how much force does it take to pull the filament through it. Then consider your adding the push through the nozzle the extruder must exert . then bend it just a bit and se how tight it gets
So then consider the tube flopping around as the carriage moves, that 'pull' pressures is constantly changing and can possibly lead to extrusion changes.
sensitive-blueā¢11mo ago
this makes sense, and also cheap to swap out
I swapped it out for a 2.5mm x 4mm reverse boden, and it still clogs on the top layer š¦
If it's not clogging on other layers while printing, and only on the top layer, something in your slicer settings is setting the nozzle too close to the print surface. Do you have 'ironing' settings enabled?
sensitive-blueā¢11mo ago
no I don't š¦