Under Extrusion & Clogging - HELP
Guys, I am at my wits end. I purchased a e3d hardened steel nozzle 0.25mm and decided to place it on my MK3 this past weekend. After replacing the nozzle, I tried to load the filament and noticed that it wasn't coming out from the extruder so i took apart the hotend/extruder to see what was the problem. After taking apart the hotend into its separate pieces, I noticed the PTFE tube clogged. I followed with putting back together the hotend with the 0.25mm nozzle. After calibrating the machine, I started to work on the first layer and have had problems ever since. The filament starts out well, but then it starts to underextrude and then it clogs up. This happens every time and usually after 15 minutes it clogs completely.
I am running PLA Prusa Filament Gold in the picture. When I extrude the filament, it comes out nicely not slowly. The file was sliced in PrusaControl with the .25mm nozzle setting. The temperature in that print was set to 215C.
Please help. I have spent too many days on this issue and dont know what to do.
Re: Under Extrusion & Clogging - HELP
Photos of the heat block, nozzle, and heat break would help.
The assumption is everything worked well until you installed the 0.25 nozzle. Hard to tell with the photos, but are you printing a filled PLA? Gold, copper flakes, or?
When you found the blockage, was it melted filament or was it debris? If debris, and it looks like there is a LOT of debris on the bed, do you hear the extruder clicking before it clogs? There is an issue with the axle on the idler Bondtech gear being too short, and it causes the extruder to skip and grind filament. Open and look at the idler door tabs where the axle goes. The axle needs to be pressed in far enough it connects to both sides of the door. Somewhere there is a video of the problem.
If the filament is melted up in the PTFE, then check the cooling fan is running. Then check that the heat break is firmly seated in the heat sink (and that it has thermal grease on the threads). After that, make sure the nozzle is firmly seated against the heat break, and not the heat block. Last would be to check thermal cal of the hot end thermistor with an IR thermometer. It may have been damaged.
And last - it's hard to tell. Is that a metal filled filament?
Re: Under Extrusion & Clogging - HELP
Check out the bottom of this Knowledge base article for info on the 0.25 nozzle. https://help.prusa3d.com/article/LND6Zdnks4-different-nozzles
"To achieve finer detail on 0.1mm or 0.05mm print settings, you can use a 0.25mm nozzle. But use it for only very small objects, e.g., a few centimeters in size. Print times can be considerably longer compared to 0.4mm nozzles. The ideal use is for jewelry."
The 0.25 nozzle is for very small and slowly printed pieces. That could be part of the issue. I used a small nozzle only 1 time to print a very small marvin and it took too long and was finicky for my taste, but it worked...
It looks like you are printing a 75x75 MM calibration square and in the beginning it looked good and got progressively worse as it proceeded. I would reduce both the flow (75%) and speed (50%) drastically and adjust the layer heights and extrusion widths and only print small things with the 0.25MM nozzle. Make sure to bump up the nozzle temp by 5 degrees for the Hardened nozzle as well. Bobstros' website has more info on nozzle sizes to refer too.
If you are printing regular size things, you might be better off with a 0.4MM or 0.6MM hardened steel nozzle, which works very well for both abrasive and nonabrasive filaments.
Strange women, laying in ponds, distributing swords, is hardly a basis for a system of governance!
Re: Under Extrusion & Clogging - HELP
Is that the Fillamentum PLA Extrafill Gold Happens available on the Prusa estore? I'm not certain, but I believe that filament contains materials to give it that sparkly appearance. Any additives to the filament can cause problems with clogging small nozzle sizes.
[...] I am running PLA Prusa Filament Gold in the picture. When I extrude the filament, it comes out nicely not slowly. The file was sliced in PrusaControl with the .25mm nozzle setting. The temperature in that print was set to 215C.
Also, one other thing to try. I had a hard time with Fillamentum's Galaxy Gray. Using Slic3rPE, try adjusting Filament settings->Advanced->Max speed override->Max volumetric speed to something like 5 and slicing again. This will reduce the rate at which material is fed into the hotend and give it a chance to keep up. The Prusa default for PLA is 15mm^3/s which is already very aggressive with the E3D V6 hotend which can process material at closer to 11.5mm^3/s. I always dial this setting down, especially for specialty filaments. It can't hurt to reduce it for normal filaments for testing as well.
and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
Re: Under Extrusion & Clogging - HELP
Is that the Fillamentum PLA Extrafill Gold Happens available on the Prusa estore? I'm not certain, but I believe that filament contains materials to give it that sparkly appearance. Any additives to the filament can cause problems with clogging small nozzle sizes.
[...] I am running PLA Prusa Filament Gold in the picture. When I extrude the filament, it comes out nicely not slowly. The file was sliced in PrusaControl with the .25mm nozzle setting. The temperature in that print was set to 215C.
Also, one other thing to try. I had a hard time with Fillamentum's Galaxy Gray. Using Slic3rPE, try adjusting Filament settings->Advanced->Max speed override->Max volumetric speed to something like 5 and slicing again. This will reduce the rate at which material is fed into the hotend and give it a chance to keep up. The Prusa default for PLA is 15mm^3/s which is already very aggressive with the E3D V6 hotend which can process material at closer to 11.5mm^3/s. I always dial this setting down, especially for specialty filaments. It can't hurt to reduce it for normal filaments for testing as well.
and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
Re: Under Extrusion & Clogging - HELP
Bob - you bring up a good point. I wonder if the extrusion limit is due to viscosity (pressure * orifice) or thermal (30w can only melt so much plastic per second). It almost makes sense that with a small orifice the pressures created could cause the extruder to force melted material out of the nozzle back into the heat break. Though I'd not expect it to get back into the PTFE; that's a long way for the heat to travel.
Re: Under Extrusion & Clogging - HELP
Sorry for taking a long time to reply back, but I wanted to do a couple of things before I replied. I changed the nozzle to a brass nozzle 0.25mm in size. However, I am still having the same issue. It starts out good, but half way through it starts to clog.
The filament that i am using is not metallic filled filament. It is similar to item Copper PLA filament Reference: FLM-PLA-175-CPR in the store, but in gold. Prusa no longer sells the filament that i purchased.
I am planning on using the nozzle for D&D figures that are small. Should i heat up the temperature to 220C?
Re: Under Extrusion & Clogging - HELP
Also, one other thing to try. I had a hard time with Fillamentum's Galaxy Gray. Using Slic3rPE, try adjusting Filament settings->Advanced->Max speed override->Max volumetric speed to something like 5 and slicing again. This will reduce the rate at which material is fed into the hotend and give it a chance to keep up. The Prusa default for PLA is 15mm^3/s which is already very aggressive with the E3D V6 hotend which can process material at closer to 11.5mm^3/s. I always dial this setting down, especially for specialty filaments. It can't hurt to reduce it for normal filaments for testing as well
@bobstro - You may have found the solution. I will continue to print using a Volumetric speed of 5 but it has not clogged (cross fingers for good luck)!
Re: Under Extrusion & Clogging - HELP
Anything that looks like copper or gold when extruded has metal in it. Metal flake anything is not recommended in 0.25 nozzles.
That's because these filaments have particles that, although still nano sized, can have issues flowing through nozzles under 0.4mm diameter. We recommend that the best printing nozzle diameter is 0.5mm for composite materials, and for any metal, glass of Carbon Fiber materials you'll need a hardened nozzle.
Some metal filled filaments are recommended with a minimum 0.8mm nozzle. Plus, there's this 'other' tidbit from ColorFabb:
This causes the filament to expand higher up, outside of the nozzle in the white Teflon piece were it can create friction. The same effect can be seen with the Ultimaker 2 hot-end. What this means is that printing with copperFill on Ultimakers requires patience and perseverance, so this is not recommended for novice users.
In i3's, the expansion would be in the heat break, not the Teflon, but expand it will.
RE: Under Extrusion & Clogging - HELP
I've been having all of the same issues as the OP with a 0.25mm nozzle, including the going crazy. This article was incredibly helpful, and I want to add my lessons to this knowledge base as well.
When I first got my MK3s, I had success in printing with a 0.25mm nozzle with default settings.
Until I got an enclosure....then every. single. 0.25mm print. failed.
After about 1-2mm z height.
I wanted an enclosure to print ABS for another project. After it was complete I had a 0.4mm nozzle on it for almost a month when it went in, so I didn't put 2+2 together when I swapped to the 0.25mm nozzle later. The trapped heat was too much, and would reliably cause the clog. I'm sure also that all of the reasons other's have mentioned are contributing factors as well.
So the lesson is, small nozzle size + PLA + Enclosure = clog.
I'm going to try backing off on the volumetric pressure as well and hopefully that may increase reliability and quality, but pulling the printer out of the enclosure immediately fixed my issue.