Why would a particular roll of PLA (“Jet” white, if that matters) start to jam after a few minutes’ use? It always seems to start off fine, but after maybe 20 minutes or so, the extruder starts to click and I end up with an air print. Given the time frame, it seems like it must be heat build-up causing this, but I’m not clear how heat creep can cause jamming. Anybody have any insight? (Running a Printrbot Simple 1405 with a metal extruder and the new Ubis hot end.)
Not an expert, but I would try running that filament a bit cooler. Perhaps it has a lower transition temp than others you’ve used.
White is a weird one. It tends to have a lot of opacifier in the form of titanium dioxide. This makes it a little harder to push through nozzles. Do try fiddling with temperatures, higher might be productive as it will reduce the viscosity.
Filament brand/manufacturer?
@Sanjay_Mortimer1 “Jet”, from Amazon. Higher heat seems to help initially, but then it seems like the heat creep sets in again. I wonder if lubricating the filament with vegetable oil would be effective?
I’m not saying this is your problem here, but heat creep can cause jamming by prematurely melting the plastic, the drive has to overcome more friction. If you can keep a sharp temperature transition, the less adhesion the drive has to overcome.
@Jeff_DeMaagd You might well be right, but I don’t know what further I can do to accomplish that - the barrel has heat vanes and is actively cooled with a fan, quite similar to an E3D, and I’ve got my retraction set at only 0.4mm now.
I’ve had inconsistent diameter filament where it would grab and chew it then cause it to plug up.
I bet you it is heat creep. When I had my jhead lite v2 I always had heat creep and prints would jam just like you said at 50min in or so. The. I would pull out the jammed filament and it would be really soft in the barrel of the hotend. If you run a fan on the main barrel (sorry can’t remember the technical term at the moment) then you will possibly solve the issue.
Some filaments melt at different temperatures so unless you are right at about 180c you could also try to drop down your print temp.
@Griffin_Paquette I actually do have a fan on the barrel, so there doesn’t seem to be much more I can do there. I certainly can try dropping the temp, though.
@Patrick_Ryan what temp did you have it set at?
Right now 210, so I’ve got a lot of room to drop. I find the layer adhesion is better at higher temperature though, so there’s definitely a trade-off there.
I’ve gone up to 225 on pla. Right now in trying dial in abs. For some reason I think I get better prints that are smooth but the layers aren’t that strong which probably leads to slicer setting
@Zane_Mitchell Cooling issue, maybe?
Post a pic of your setup. I run a genuine e3d. Drilled the wade extruder to accept ptfe tube to slide down all the way through the heatbreak.
@Zane_Mitchell I meant your ABS intra-layer strength issue.
Tried a bit of foam as an oil dispenser. Seems to be working!
No cooling on the abs. I may just need to enclose or refine slicer.
Yeah, I keep reading about the need for enclosure with ABS, and intra-layer adhesion seems to be a big factor.
What everyone else said. Also, I’ve only tried JET filament once, but the diameter was over-spec, which of course makes it prone to jamming. “3mm” filament should actually be closer to 2.85mm diameter, but the JET stuff I tried started at 3mm and went up from there.