0.25 nozzle impossible load  

RE:

The 0.25 mm nozzle is a bit trickier to work with. "Partial clog" sounds spot-on.

- Remove the nozzle

- let a 2 mm drill drop (carefully) with its blunt head into the filament end of the nozzle. It should slide in to its full length (+/-)

- if it scratches or gets stuck, there is filament sticking on the inside. I've used the sharp end of said drill repeatedly to clean it up - not a pretty procedure but the nozzle seems to survive (try not to scratch the metal as far as possible. Clamp the drill - requires a sharp drill - in a vice and rotate the nozzle between fingers against it)

- Read up on using thermal paste against "heat creep". The idea is to minimize temperature drop between nozzle cold end and the head's heatsink. Also watch heatbreak temperature (put on footer) - it shouldn't go far above chamber temperature. Otherwise, check heatbreak fan e.g. stringing loves to collect in there.

- Oiling the filament (standard operating procedure for me, controversial topic for many) doesn't seem wrong here as the oil is exactly where you need it to prevent filament sticking (but extruding it into the bulk of the material ideally makes it a PPM contamination, that's at least the idea why it shouldn't affect print quality as in layer adhesion etc).

- I use the 0.25 mm nozzle with ASA and the MMU. It's a royal PITA but works reliably when set up carefully.

- Possibly lower retract settings (both distance and speed e.g. divide by 2 or 3) as this transfers heat from the hot zone into the cold region with the retracted filament.

RE:

Note on above, the procedure starts only after cold pull fails (which doesn't even require nozzle removal). If you haven't tried cold pull, spend an hour (or two or three - the cooling time adds up) to perfect your cold pull procedure. But, if the nozzle is really clogged you may not be able to get filament through. In that case, the drill.

Then, if the failure happens again (which is already quite unlikely when the printer is running smoothly) "cold pull" is part of routine operation.

And, a spare nozzle can come in handy to make it more reliable.

RE: 0.25 nozzle impossible load

Hi, have you checked correct settings of you printer? (see picture menu "Settings->Hardware->Print head") If you are using standard 0,25 nozzle, uncheck hi-flow nozzle option

RE: 0.25 nozzle impossible load

Posted by: @pako

Hi, have you checked correct settings of you printer? (see picture menu "Settings->Hardware->Print head") If you are using standard 0,25 nozzle, uncheck hi-flow nozzle option

Yup, I made that mistake once. I rarely use a 0.25mm nozzle, they are such a PITA. I got into a phase where I needed it to print lithophanes but at 13 hrs each, I'm kind of over it... 

RE: 0.25 nozzle impossible load

THANK YOU ALL!

So, as for the “partial clogging,” I find that hard to believe since I'm getting the same result with a brand-new nozzle

As for the settings provided by “PaKo,” I did indeed change all of those.

What I need to check is the heatbreak temperature—I didn’t know you could display that at the bottom of the screen.

I have to admit I don’t really understand the idea of using a drill, given that my nozzle is brand new?

RE: 0.25 nozzle impossible load

One thing I forgot to mention is that I’ve already printed for several hours (like 50 or 60) using a 0.25mm nozzle with wood filament (which caused me some issues, hence why I changed the nozzle to make sure I was starting from scratch).

RE: 0.25 nozzle impossible load

Posted by: @pyromanprod

THANK YOU ALL!

So, as for the “partial clogging,” I find that hard to believe since I'm getting the same result with a brand-new nozzle

As for the settings provided by “PaKo,” I did indeed change all of those.

What I need to check is the heatbreak temperature—I didn’t know you could display that at the bottom of the screen.

I have to admit I don’t really understand the idea of using a drill, given that my nozzle is brand new?

The point of the drill is you can use to remove partial clogs. You twist it manually in the heatbreak tube. You can also use it as a probe to determine where the clog is.

Printing PLA can be tricky on a Core One due to heat creep causing clogs with small diameter nozzles. I generally keep the door open with I print PLA. 

RE: 0.25 nozzle impossible load

Posted by: @pyromanprod

One thing I forgot to mention is that I’ve already printed for several hours (like 50 or 60) using a 0.25mm nozzle with wood filament (which caused me some issues, hence why I changed the nozzle to make sure I was starting from scratch).

it's possible the material even recommends 0.6 mm nozzle size so this is unlikely to work reliably. Cleaning this nozzle is still probably unproblematic, just try cold pull with PLA. That stuff is very sticky when barely molten.

RE: 0.25 nozzle impossible load

Posted by: @pyromanprod

One thing I forgot to mention is that I’ve already printed for several hours (like 50 or 60) using a 0.25mm nozzle with wood filament (which caused me some issues, hence why I changed the nozzle to make sure I was starting from scratch).

I didn't see the part about wood filament. I don't even print wood with a 0.4mm nozzle. I only use a 6 or an 8. 

RE: 0.25 nozzle impossible load

Hi, there is another thread for clean nozzles by "driling" https://forum.prusa3d.com/forum/prusa-core-one-hardware-firmware-and-software-help/diamondback-nozzle-clogged/#post-768179

RE: 0.25 nozzle impossible load

Thanks to everyone for your help. What’s bothering me is that now that I have brand-new nozzles I bought from Prusa (two of them, actually), I’d like to use them for regular PLA (not wood), but I just can’t seem to get the PLA to feed through these nozzles at all.

RE: 0.25 nozzle impossible load

Posted by: @pyromanprod

Thanks to everyone for your help. What’s bothering me is that now that I have brand-new nozzles I bought from Prusa (two of them, actually), I’d like to use them for regular PLA (not wood), but I just can’t seem to get the PLA to feed through these nozzles at all.

Is the PLA dry? Do you have a filament dryer (not a dry box) you can dry it in? Preferably 50C for 4-6 hrs. 

RE: 0.25 nozzle impossible load

Damn, if we start pulling out the humidity card, it means we don't really have any ideas left… Too bad.

Yes, yes, it's dry. I've tried several PLAs, even brand-new ones, ran another through the dehydrator, etc. All the spools can't be humid.

RE: 0.25 nozzle impossible load

I've only print Overture matte PLA through a 0.25mm nozzle. What temperature are you running the nozzle at?