MK4 nozzle wear after 2 weeks ?  

RE: MK4 nozzle wear after 2 weeks ?

Yikes, that shouldn't happen at all. I use mainly PLA and have never had to change a nozzle before. The nozzle should remain generally clean as well. Then again I only use Prusament too.....

You'll need to replace the nozzle of course. Do you have any marks etc on the print bed/PEI sheet? Wondering if the nozzle has been dragging across it and wearing.....

First image is ideal, second image shows lack of squish - most likely due to uneven wearing of the nozzle meaning the z-height calibration would be inaccurate. This will cause prints to come loose from the bed and fail. 

Replace the thermister and the nozzle, before running a calibration. Clean the PEI sheet with IPA, or dis soap and hot water. Then keep an eye out while using different filaments to see if one of the non-Prusa filaments are causing an issue?

RE: MK4 nozzle wear after 2 weeks ?

Does some of that filament have glitter in it? If so that might explain excessive nozzle wear. Some glitter filaments contain glitter particles that do not melt in the nozzle, and then scrape against the inside of the nozzle. Always check manufacturer notes and user comments any time you use filament that has infill of any kind (wood, metal, glitter etc.) Some of them are safe to use in a brass nozzle, but some are not. Also, if the manufacturer recommends a large nozzle size (>= 0.4 mm or even 0.6 mm) that may also be a warning sign that the filament has non-melting particles, even if nozzle wear is not explicitly stated. For those filaments don't use brass nozzles, but instead any of the hardened nozzles: e.g. ObXidian or hardened steel.

RE: MK4 nozzle wear after 2 weeks ?

I did print several things with the Prusa galaxy black but don't think I even used 1/3 the spool. Not sure if the Creality silk stuff has particles? Towards the end before failure the nozzle seemed to rub and cause vibration across parts with the waffle infill. I wonder if this accelerated the nozzle wear?  The PEI sheet looks good, other than a few small dings where it calibrated Z during bed leveling I'm guessing ? I do have hardened nozzle coming with the V6 adapter and new heat and thermistor sensors. Thought it would be nice to have backup hot end with easy swap nozzles. Now its time to hurry up and wait...   Oh I also had used a little Overture White, I guess I have heard they use titanium dioxide in a lot of White filament? Partsbuilt3d I noticed was in Ohio where I found most parts in the US online.  Thanks for the tips !  Oh and I do always clean sheet with 91% IPA and will post update after parts arrive!  Will try larger .6 nozzle when it arrives also

RE: MK4 nozzle wear after 2 weeks ?

to me and I may be wrong but the tip looks like it's been rubbed down with a file ???

RE: MK4 nozzle wear after 2 weeks ?

That what got my attention, you would think that was dragging on carbon fiber prints at an angle for days ! I am sort of surprised the customer service rep did not see or suggest i replaced the nozzle even if it was a non warranty item, let me pay the diff and let it ride along with the thermistor they are sending under warranty 🙁 

RE: MK4 nozzle wear after 2 weeks ?

When I ordered my MK4 I also purchased the V6 nozzle adapter and one of the "Diamondback Nozzles – V6 Compatible – Polycrystalline Solid Diamond Tip 3D Printer Nozzles, Improved Extrusion" from Amazon so that I wouldn't have to worry about nozzle wear for a long time.

RE: MK4 nozzle wear after 2 weeks ?

I have put many spools of Prusament galaxy black through a brass nozzle and not had wear problems.   That should not be the cause.  Double check your filament specifications.  

Nozzles wear from rubbing as the filament hardens after exiting the tip.    Wood or CF, carbon fiber, filament will wear a brass nozzle.  CF can wear a brass nozzle in minutes.  

Are you using anything abrassive to clean the nozzle exterior?  

As noted a Diamondback nozzle should not have wear problems.  I have switched to one, but there are some differences in how it works with smaller PETG parts.   I stuck with the brass nozzles for 2 years since most of the data is for brass nozzles.  After more experience and using  CF, I went to the diamond. 

RE: MK4 nozzle wear after 2 weeks ?

seems you have broken thermistor

RE: MK4 nozzle wear after 2 weeks ?

New thermistor and nozzle and she was printing smooth as butter again!  

RE: MK4 nozzle wear after 2 weeks ?

How would a broken thermistor cause such wear like this?

Not doubting it, just trying to learn and understand how it could be the issue.....

Thanks

RE: MK4 nozzle wear after 2 weeks ?

That was best guess of customer service and they asked for a close side shot of the nozzle, so I am guessing it was all the wedge shaped nozzles fault and probably not thermistor but I installed both anyway since I had it out.  I think they were judging the problem more from the print examples and didnt zoom in on the nozzle pic and missed it.  Reminds me when my teen daughter got her arm broken in car accident and the hospital took xray just below the break and sent her home 😑 

RE: MK4 nozzle wear after 2 weeks ?

Did you print any glow-in-the-dark filament? That stuff is very abrasive.

RE:

No glow in the dark stuff, just maybe 1/4 roll of Prusa Galaxy Black, Overture White, and 2 Creality 2 tone silks ( Red / Yellow and Blue / Green ) that is about the only stuff I can think of that has sparkles, or metallic or shiny particles.  I think it was accelerated when I heard lots of vibration noise when tip seamed to rub on a bowl and a few things while printing the waffle infill pattern, I think I read here on forums certain infills the nozzle hits the high spots when moving the opposite direction on infill? 

RE: MK4 nozzle wear after 2 weeks ?

I think white filament can also be more abrasive than other colours, but it shouldn't be that abrasive I guess. With "silk" filament I have no idea but it does sound like it could be abrasive as well. 

Regarding infills, yes some, like eg triangle infill do ram through crossing layers. If you want a less harsh infill type, stay with infills where crossing lines are separated by layer properly. There are number of infill types without any clashes, like for example rectiliniear or honeycomb infill.