Prusa i3 MK3 extrusion issues
I just received my prusa MK3 printer and finishes assembling it and finished all ththe calibrations. I went to test it out with one of the pre loaded files, (the bottle opener) and walked away for a couple minutes. I saw that it was having some issues extruding but I let it run all the way to the end just to see if it continued. I added a picture of the finished product.
I then proceeded to start messing around with everything I could think of. I I’m loaded and reloaded the filament. I messed with the screws and tension. I tuned my z axis multiple times. I put my flow rate at 200% but with no success. I tried printing just a flat sheet for these tests, (a 4”x 4” square at .1 thickness and ran that through cura). Another picture added below.
Is my extruder clogged? Not hot enough? G-code bad? Any suggestions and advice would be great, thanks!
Vince.
Re: Prusa i3 MK3 extrusion issues
0.2mm is the normal first layer... that's what you should have used in Cura... The fact it sliced it, means it printed it at 0.2mm though. Just a heads up. 😉
The 2 tension screws for the bondtech gears, on the left side of the hot end towards the top, should be roughly "flush" with the plastic. If they are too far in, or too far out, they can cause issues.
I'm not sure how to test for this, but do you think your optical sensor could be getting hot, and making the PLA get soft? Do you have any ABS or PETG? (with petg always use something to protect the bed, read the manual, don't blame me if something goes wrong with petg) If something is "warm" and making the PLA "soft" before the bondtech gears, the higher temp materials, won't be bothered nearly as much, and thus would print much better.
Are your extruder gears lined up properly? It seems like a repeating pattern... like, "once per revolution" of the feed gears kinda thing?
I honestly don't have any idea that's not a shot in the dark as to what would cause this... the fact it's "repeating" bothers me in that it really seems like something is twisting/moving/flexing/something, once per revolution of the extruder.
EDIT: Look at your 4x4 square. See how "wide" the "no extrusion" is, and then as it get's closer to the full width, the "no extrusion" is very narrow? I'm over 50% sure whatever the issue is, lies in SOMETHING is BENT in the extruder assembly.
Hi, I'm Sean. I used to work on CNC machines.
I try to not make mistakes, but the decision is YOURS.
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Re: Prusa i3 MK3 extrusion issues
Hello there,
Please excuse me, if I'm using bad English.
I've purchased a Prusa MK3 a while ago but I just assembled it recently and I have the same Problem as Vince. I don't have much printing experience, I only have a cheap one (Wanhao duplicator i3) I have played around with for around 1 years.
My prints / the quality looks exactly the same.
I'm using PLA only at the moment.
So I've been trying to get some help from the web, but nothing really revealing so far.
I've tried the extruder calibration, and the extrusion is always some off. After a few tries, I noticed that the "Extrusion speed" is not the consistent. After a few cm it will slow down and then go on again. That's the reason why the print looks like that, for a short distance there is almost no "filament feed".
So I've been playing around with the E-Steps (which is around 455 now, seems abit high compared to what I saw online?). It got abit better but not good enough
I checked the bondtech gears, they are turning at all times!
I checked the screws, I tried to loosen them, I tried to tighten them (actually the result when tight is much better).
I cleaned the nozzle with a cold pull, it's super clean (since I just assembled it recently).
I tried to use a higher temp, but then the extrusion becomes even more incosistent.
I'm really getting desperate now. I have no clue what else I could try or do. I really hope someone could have some advice for me. It would make my day!
I turned up the heat until 225-230, the result is "better" than before, but still not satisfying at all.
Re: Prusa i3 MK3 extrusion issues
Duc,
I don't know exactly what is wrong, but something isn't right in your extruder. If it were *my* machine I would completely disassemble the extruder and reassemble. I would strongly recommend using the online version of the assembly manual as the photographs are much clearer. Pay particular attention to the part where the drive gears are aligned to the filament, and the initial tension adjustments.
Re: Prusa i3 MK3 extrusion issues
I would also try another spool of filament.
I'm way low on the printer experience scale, but you may have moist filament.
If another (good) spool is the same, ignore me.
Re: Prusa i3 MK3 extrusion issues
Thank you guys for your advice!
I've been able to fix the problem, by really disassembling the whole extruder and re-assemble it again.
I've been running the filament through the gear after each step, to see if there are any obstructions. I've placed the hotend a little far away from the other parts since I had to heat it up to manually control the bondtech gears.
The result was that I had no obstructions at all. So I guess there must have been a small mistake in the buildung process, just as paul suggested. After reassembling the whole thing (phew), it worked out perfectly fine. The Extruder Calibration was spot on with the inital E-Step setup of 280.0 .
And I have been printing happily since then 😀
Thanks again!