Vcore4 500 stock hardware - Hotend keeps jamming on long prints
Just like the title says, my hotend keeps jamming during long prints.
The timing isnt consistent, and I have tried lots of things, including tuning retraction.
I am using Orca Slicer. It is a 0.4mm nozzle, not the default 0.6 that came on my hotend.
I have tried different filaments, different brands different materials(all different kinds of PLA).
I then used the same filaments on other printers without issue.
My vcore3 is being workes on right now, but it wasn't having any of these issues, despite very very similar hotend/extruder wise.
There are a few reasons I have been looking at retraction:
1. the "jam"(if you can call it that), is very simple to remove as long as I catch it early, and the extruder doesn't grind through the filament.
The tip when I pull it out only looks very very slightly bulged, like how you'd expect. It comes out with only a little resistance.
2. The nozzle is clean, and been cleaned several times. The nozzle itself doesn't ever clog.
3. When the print "fails" its a clean fail, in that there is no spaghetti, or any artifacts to indicate where it failed. It looks like it finished a line, retracted, but couldn't unretract(or didn't unretract).
4. Fixing it, is just a matter of pulling the filament, snipping it, then loading it back in. Next print works fine until it doesn't.
I have installed an orbiter filament sensor on top of the extruder, and just today for good measure(I'm tired of wasting filament), I installed a spare btt smart filament sensor v1 into the filament path(closer to the spool side), to hopefully catch if the filament stops moving....but its only accurate to 7mm, which isn't amazing.
Anyway, glad to share whatever info or pictures or tests you guys want. Im at a loss here.
27 Replies
Did you install the short piece of ptfe tubing between the extruder and the hot end?
Yes
What type filament and what temp? Wondering if that short ptfe tube is the correct length.
PLA, matte, regular, silk, all do the same. Printing between 215 and 220 usually, 20mm/s
Yeah, the tube is correct length, It was a bit long, and I could feel it compressing when I bolted down the extruder, so I shortened it a little bit till it fit snug
Just to be sure, ill completely replace the tube with a new one. Perhaps it got kinked or something
You replaced the short one in the hot end or the long one that feeds the extruder?
Do you have a set of calipers or an accurate ruler to double check the length of that tube? It should have been the right length and been putting just a little bit of compression when you installed the extruder. It should not be much though
So, I meant that I WILL replace it, not that I have.
I did replace the long one with a larger 3mm ID tube.
I WILL tonight replace the short one in the toolhead, just to be safe.
I do have calipers
and I use them
I think its good thing to try. I dont remember the exact length but I think its like 23.5mm or something very specific like that
24.7 maybe?
iunno
ill look it up
the longer one at 3mm should be fine it just might not be that strong and can kink. I think that is why people like the 2.5/4mm stuff
Yeah, I might switch that eventually
But for now as long as I home the hotend before loading/unloading, its fine
(it does kink at Y 500)
24.5mm
thanks
the other thing I had on mine was the bottom of the extuder has a screw in metal part that the filament comes out of. I think it protects the plastic frame of the extruder. It was not screwed in all the way and that was part of my problem with it not sitting flat. Make sure the bottom of the extruder does not have that insert sticking out.
if your long tube at 3mm is not kinking you should be good there from the extruder not being able to pull the filament and if the short piece is correct I am not sure what to say. Do you think the tension knob on the extruder is to loose?
I don't think its tension knob. I am not exactly sure how to tune that, but what I do is use the UI to manually extrude 200mm at 15mms (the UI is cubes not squared), and tighten the knob till it starts to click, then back off till it extrudes smooth
thats more scientific than I do 🙂 First time I had it cranked down until I saw filament dust around the toolhead. I loosened it up and just tightened it till I felt like there was some tension on it and left it alone
heh, well I do not think it is that
It HAS to be the inner ptfe
or heat creep making a plug?
But I haven't had that happen in ages
not with a modern hotend and a decent fan
It seems like its that inner tube. I have not had any jams with mine since I replaced the long tube feeding the extruder. I have a 500mm as well.
I also wonder how accurate my nozzle temp is. I just watched a YouTube review where he got a bad hotend
I was an early bird
I been noticing my nozzle oozing when it moves, but not an issue on my other printers
The default printer profile does have 120mms retract speed which seems pretty high
if its an early printer you got, you could have that issue. I got mine the 2nd day of the original preorder shipments and it been fine. I think people were trying to see if they could melt PLA against the side of the nozzle as a test. I think most PLAs melt around ~180. Do you have another printer you can see how low you can crank down the temp on for a specific roll of filament before it wont melt and then try that same temp on the VC4? There easily may be 5-10C between two different printers but I suspect there should not be 15-20c difference. Could be an interesting experiment if the short ptfe tubing does not fix it
ooo good idea
ill do that
Ok. Well, I just cut another piece, that's perfectly 24.5mm according to my calipers, however accurate they might be
The lights in my garage burned out, so will have to wait till tomorrow to install and test it
I installed a new ptfe, and I did tighten the umm...threaded insert/guide deeper. it was definitely sticking out just a bit
I started a 30 hour print 10 hours ago. So heres hoping
good luck!
nothing like jumping in feet first with a 30 hour print 🙂
Well, its only been failing on really long prints, and always at least 7 hours in. Last one failed 20hours in.
:/ Hopefully that fixed it. Good luck!
So far so good!
31 hours down, 4 more to go
Solution
Yep. Seems to be fixed now.