I’m having trouble with my extruder after changing to an e3d V6 hot end from a J-head I had been running for 1.5 years before its thermistor fell out and turned into a plastic blob. This extruder previously worked reliably with the J-head, only one screw (the far one) in the idler and a weak spring from a pen.
After changing to the e3d V6 I can’t get reliable extrusion before the hobbed bolt strips the filament. The video shows about what happens. I have corrected/tried:
Thermistor set to the Semitec as recommended, instead of my old Epcos 100k (this was wrong for a while, but fixed recently)
Cold pull of filament was clean, able to see light through the nozzle
Adjusting idler tension across the whole range I can manage
Manual extrusion with the hot end out of the extruder body (which felt tougher than I imagined, but I never tried before)
Turning the nozzle temperature up to 250C with ABS
Adjusting stepper mounting with respect to big gear, in case hobbed bolt was being pushed by a slightly elliptical gear
Cleaning hobbed bolt when it grinds (hobbed bolt was bought from Airwolf out in California)
Things I haven’t tried/corrected yet:
Different roll of ABS filament that has been sitting in a bag with desiccant
PLA and Nylon Bridge filament
Slight misalignment of hot end with extruder body. Maybe 4 degrees off square with bottom of extruder body
when I replaced my airwolf3d hotend to e3d v6, I got some gap between filament entrance on hotend and filament exit on extruder, that was causing a jam and grinding, when I got rid if this gap, everithing went perfect. Of course, made PID autotune, Z level adjustment, nozzle diameter adjustment.
when you did your hotend build up did you do the final heat and torque? Its the last step and one of the most important in the build guide. If you skip it youll get a gap where the “plug” forms and it will cause all sorts of hell after a few retractions.
For all, I haven’t gotten to the point of printing a part yet, I’m just extruding via my host software. There are a few times in the video where the filament grinds and stops feeding (you can see the black line pause in place for a little while), and actually manages to catch up and feed some more.
@Wing_Wong The nozzle is 0.4mm, up from 0.35mm (updated in slicer), PID was tuned on initial build of the e3d a few weeks ago, retraction updated per e3d’s recommendation, but this test doesn’t include retraction.
@Phil_Hord , manually pushing the filament through works. It’s not rough, but it’s not super easy. The filament I’m using measures 2.9mm and feeds very easily through the body of the hot end until it bottoms out in the nozzle. What kind of oil would you recommend? I would think it would eventually find its way out through the nozzle, and I wouldn’t be excited for it to flare up.
@Zviad_Sulaberidze , I am worried about the interface between the hot end and the extruder, especially considering that I couldn’t get it seated flush.
@Joe_Spanier , I did this step on the initial build, but forgot this time around. I will go back and do it.
@Tim_Sills , I definitely want to try a different extruder body. I’m not happy with how the e3d is seated and held in the jhead style here. I’m considering this one http://www.thingiverse.com/thing:725082. I don’t have a PTFE tube in this one, but maybe I will look into some way to make sure the filament hole in the extruder body is better aligned or more smoothly feeds the top of the hot end.
Thanks all, I will report back with progress later.
In the video when the filament pauses, so does your extruder gear. This is not grinding. It’s probably your extruder stepper driver overheating. Try turning the gear manually backwards by hand when it pauses. Is it pretty easy to turn without feeling the stepper fighting you? If so, check the cooling on your stepper driver, or turn the current down so it runs cooler.
in that gap, the filament bends and blocks the movement, it was happening to me, it was not even getting out from the nozzle, the jam was happenning before. Make something with it, what dia. is the filament/hotend? if it’s 1.75mm, you can put longer PTFE tube, up to the hobbed bolt/extruder exit. If it’s 3mm, you have to put something between extruder and hotend entrance with the hole bit wider, than a filament
Very similar problem when I upgraded my nozzle recently. I was extruding too fast for the new design to handle. Would extrude great for a bit while pressure was building up in the melt chamber. Then pressure would build to enough that the filament would stop moving and the hobbing would strip the filament. Then obviously extrusion would not work properly due to the stripped section.
@Phil_Hord I agree with that assessment. It is not grinding in this video. @Tony_Olivo I use a Wades extruder with E3D v6 and discovered that the screws used to hold it in the extruder are not spaced perfectly which can cause that 4 degree tilt. I found that by swapping which screw gets tighten down first the tilt goes away. Try that and see if it makes a difference for you.
About the gear stopping, that’s just the time it took me to hit “Extrude” in the host software. The best example of the filament stopping feeding is probably at the end of the video, just before the gear turns off. You can see the black line on the filament stop while the gear is still turning just before the end. Throughout the video the filament is sort of wagging side to side rather than traveling straight toward the extruder.
I’ll try extruding extra slow, then will work on improving the alignment of the hot end with the extruder. I will get some PTFE tubing on order. Probably 4mm ID. I would go with 3mm ID, considering most filament I have encountered is 2.85-2.9mm, but it’s probably safer with 4mm.
For that last half-second of the extrusion I can see where the filament stops feeding as the gear continues to turn. The extrudate also slows down at that point and halts just as the video stops. It looks like the extrudate slows markedly before the grinding (which would make sense) but it’s hard to tell for sure from this angle. It does appear to be binding somewhere.
What does your hot-end temperature show during this failure? Is it consistent or does it fluctuate up and down?
I haven’t tried oil myself but I’ve heard of people using canola oil and other high-temp oils. I think this is mostly for PLA and bowden tubes, though, and I wouldn’t recommend it as a permanent fix. I only meant it is something you could try to see if it alleviated the binding. If it does, it suggests that you’re dealing with friction, not step-failures, nozzle-blockage, temperature drops, or a dozen other things that can cause intermittent extruder failure.
I’ve heard of some issues with temperature creep in the melt chamber on all-metal hot-ends. Feel the cooling fins on the hot-end while it’s extruding. It should be rather cool to the touch. If it gets hot it may indicate your cooling fan is obstructed or failing.
As @Guy_Bailey suggested, I was able to get the hot end in better alignment with the extruder by turning the mounting bolts individually. Cutting the extrude speed from 150mm/min to 75mm/min as suggested by @Clayton_Harry_Mills let me extrude a length for calibration without grinding, so I guess there might have been excessive back pressure. I was then able to run a 30 minute test print successfully.
I suppose I will need to work out how to limit the max speed of the extruder, which may end up limiting my total print speed. For now, that is better than not being able to print anything!