Repeated extrusion problems, trying to diagnose
When I received my pre-assembled Mk3 it was printing fine. Everything I threw at it came out okay, from all the models on the SD to some rather intricate gaming miniatures, Any problems were due to model errors or something I had forgotten to check. Suddenly though my prints are failing halfway through. Extrusion simply stops, yet the print head keeps moving till the model is 'complete'. This happens regardless of the model used - from a simple cali cat to a Colonial Viper.
I posted this on Reddit and received a couple of responses. First was to check the extruder gears, but I'd already done that. I just kept gently tightening them till they were able to grip the filament and no more, as suggested by Joan in another thread. The other was that this was a heat creep issue. It was suggested that I should try a temp tower, so I did. Here's the result.
It failed by the time it got down to 200. Now the problem I have here is that I've had conflicting diagnoses from various people. The first is that 200 is the lowest I should print with that filament (Prusa silver) is 200, although I'd been printing just fine at 195 previously. The other is that it's heat creep. But given that heat creep is a slow buildup of temp over time, how would I ever be able to distinguish between the two causes? I'm really at a loss as to what I should do next. Right now I can't print anything.
So, if anyone can either suggest what is causing my issue, or just let me know of a test I can run which would definitively isolate the cause, I'd be mighty grateful.
Re: Repeated extrusion problems, trying to diagnose
be a devil, print at 215 first layer, 210 all other layers and reduce your retraction to 0.6mm,
and try again!
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
Re: Repeated extrusion problems, trying to diagnose
These kinds of issues can be caused by a lot of different things, it's going to be hard to make a definitive diagnosis over the internet. Both diagnoses you mentioned are plausible, although I'd be skeptical of 200 being your lower limit. You could try decreasing your top speed (Filament Settings -> Advanced -> Max volumetric speed) - that won't fix the root of the problem, but it might tell you more about it. I'd guess that a heat creep issue would get worse with slower speed, but an issue outside the heat break should get better.
I can say that when I had a similar issue recently, it turned out to be caused by a partially clogged nozzle. Cold pulls (sometimes more than one is necessary) can help, but I didn't have much luck with mine. Rather than fight with it, I just swapped the nozzle with a spare I had laying around - that completely fixed the issue for me. Certainly no guarantee that's your problem, though.
Re: Repeated extrusion problems, trying to diagnose
Joan - I'll give that a shot, it was going to be one of my next moves anyway. The reason I hadn't tried before is that previously those temps were always failing for me. I keep forgetting this is a new printer so might not have the same issues.
Stephen - I already reduced the maximum volumetric rate some time seeing as the Prusa preset of 15 for PLA is way above what's recommended. It never seemed to result in any problem. As for the nozzle, I have one ordered and it should arrive soon. Maybe it will solve things. I'd like to try something else while waiting though, in case it's not a nozzle issue.
Thanks both of you.
Re: Repeated extrusion problems, trying to diagnose
Did you solve this issue?