I’ve been having trouble with PLA prints failing, and decided to try recalibration my machine’s esteps. Problem is, it seems like the amount of filament extruded changes each time I attempt to extrude 100mm. For example, I had esteps set at 908.0 for a few attempts. The first attempt, it extruded 88mm. Second attempt, 95mm. Third attempt 94mm. It just seems kind of random. Has anybody else run into this sort of thing while trying to calibrate esteps? Any ideas on what is going wrong?
I’ve experienced that too. Try slowing down your extrusion speed to 50% or even less while doing that test until you get consistent results. That did it for me.
The problem also might be caused by not enough pressure on the idler bearing pressing the filament into the hobbed bolt, or a clogged-up hobbed bolt, or your extrusion temperature could be too low, or you might have a partial nozzle clog.
My bet would be that simply slowing the extrusion speed will make the result become consistent.
Thanks for the suggestion MikeO, that worked. I had been extruding at 100mm/min while calibrating, with random results. Bumping down to 50mm/min made the results far more consistent.
While getting better calibration didn’t fix my PLA printing problem immediately, I think it helped. I’ve been trying printing at various temps again, and at 210C it seems to be working better. I’m near the end of a 2 hr print and all looks good, whereas it had been failing after about an hour consistently.
I had a similar problem and it turns out when I switched to the hexagon hotend I needed to turn up the pressure on the idler bearing for the filament. It takes more force to push the filament into the hexagon hotend for some reason.
I’m coming to the conclusion that often you just can’t push as much filament through the Hexagon hot end as many slicers assume – S3D, Cura, etc. – and am tending to generally reduce the default extrusion speeds down quite a bit.
If your extruder will only calibrate correctly with a slower extrusion rate for a given material and temperature, then I think you shouldn’t try to use it at anything above that rate.
Well, that print I mentioned previously ended up failing right at the end, so not out of the woods yet.
I have tried slowing down the extrusion rate a bit, without success, but I’ll try lowering it a whole bunch. Will also try tightening the idler.
Update on this…
The print I was trying finally worked, and now I’m about about 10 hours into a 14 hour print with no problems at all. Best success I’ve had yet with PLA, so now I’m feeling optimistic.
As for how I got it to work:
Basically had to go through total destruction of one of my print heads to make progress. I was using an AO hexagon hotend with a 0.4mm nozzle. After going through numerous failed prints and trying all kinds of different adjustments, I decided to try the suggestion of dipping the filament in a bit of canola oil. Ouch big mistake, the hotend immediately started leaking huge amounts of plastic around the nozzle. I mean huge globs pouring out the sides of the nozzle. Halted the print, cleaned up the mess, then tried to remove the nozzle. The nozzle promptly snapped in half, leaving the nozzle threads stuck inside the hot end. This was with very little torque while trying to remove the nozzle. That was kind of a jaw dropping moment.
Anyway, I had another brand new AO hex hotend, so I assembled that with a 0.5mm nozzle, and tried another print with these changes:
- tightened the idler bolts down real tight
- bumped down all the speed settings in slic3r to under 50
- printing at 205C
And viola, the 2-hour print that had been failing every time printed perfectly, and now the 14-hour one is almost done.
So, I’m not sure exactly which change did the trick, but my problem seems to be solved.
One thing I get from this is that using canola oil is probably a risky proposition. I will not be trying that again. I think if you are resorting to that, there is something else you are doing wrong.
Second is that I suspect the AO hex hotends may have some quality control issues. Reason I say this is that with the first one I was using (that got destroyed), I noticed that it was consistently difficult to smoothly insert filament into the extruder and down into the hotend. It would always feel like the filament was scraping against something in the hotend, and it alway felt like a rather tight fit. Adjusting the positioning of the hotend within the extruder did not seem to help.
However, with the second hotend that I’m now using, I see none of those issues. The filament goes right down into the hotend with no resistance. So perhaps all the issues I was having were just because that first hotend was a dud.
Anyway, thanks for the suggestions folks, not sure what specifically did the trick, but problem solved.