I’d like some expert’s help here - I started to have periodic under-extrusion problems (I have been printing successfully for a while now). So, the natural assumption is a clogged nozzle. Indeed, several cold pulls (http://bukobot.com/nozzle-cleaning) showed some black carbonized plastic, which got all cleaned up, as far as I can tell. But, I still can’t get the constant extrusion going for more than several minutes, as once in a while it stops extruding, and then recovers on its own after a while too, if I keep it going (e.g. I can see skipped/thin layers in the middle).
It’s not the feeding issue also, as hobbed bolt skips when idler tensioner is tightened normally, and bends and jams filament not feeding into the hotend when it’s overtightened…
So, should I keep trying to clean the nozzle? I don’t really want to take it apart and disassemble the hotend (it’s E3D v5)… I haven’t tried pushing wire through the nozzle yet, but my understanding it is usually required for hard clogs.
Any other suggestions? Should I look into some other possible causes? Thanks.
Is your filament reel tugging? Inconsistent tension could cause such an oscillation of extrusion. Is your roll heavy? How is it mounted?
It’s not the feed issue, as explained in the post. But nevertheless, the spool is mounted on top and rotates freely. It is reproducible with short stock of filament, so got to be in the hotend…
Have you watched your ectruder temp graph for anomalies ?
@William_Frick any recommended way of doing it? I have XXL LCD connected to RAMPS and I don’t see any spikes or drops in temperature more than 1-2 degrees…
@denix Sounds good then … no other ideas.
So it’s definitely filament slipping on the drive gear, not the motor skipping or the gearing slipping, right? Sounds like a wade’s/greg’s extruder? Have you tried removing the extruder mechanism and pushing filament in by hand to see how it feels? Have you tried a different filament?
@Whosa_whatsis the drive gear is not skipping, as I was able to get nylon filament to bend and jam instead of going into the hotend, when enough pressure is applied on the tensioner and it can’t slip. It is RoBo 3D and the extruder is indeed Greg’s Wade. I have tried different PLAs and Taulman Bridge nylon. I can definitely try pushing filament w/o the extruder mechanism…
I was just thinking - can the hotend inlet hole be slightly misaligned with the extruder mechanism hole cause this issue? Although, E3D v5 has a wider funnel-like inlet hole, IIRC…
Yup, that can do it, especially with stiff, high-friction filament like PLA or polycarbonate. The misalignment has to be worse to produce the same result with nylon.
Hi, Intermittent faults are always the worst things to resolve. I might suggest that just for the process of elimination you should swap all the motors around and then do some more test prints. At least this way you will have ruled them out as a source of the issue or found a fault.
Good luck
I just started having weird extruder problems and went from thinking it was a partially clogged head to something’s up with the extruder motor or that it might be slipping.
In the end I had to increase the print temp to get a better flow, which I suspect was a by-product of absorbing moisture. Have you played around with the temp settings?