Weired droplets and strings  

Have you changed your nozzle recently?

Cheerio,

RE: Weired droplets and strings

Leaking nozzle almost certainly.

RE: Weired droplets and strings

Mh, yes, very good point, not long time ago I installed a new nozzle. Do you think this is because of a faulty nozzle or shall I just tighten it more? Thanks for the support

RE: Weired droplets and strings

Depends on what nozzle you bought.  The prusa hotend uses E3D nozzles.  Genuine E3D  nozzles are made to a very high standard.  I have never had a problem with any one of theirs.
Unfortunately they are widely copied and many of the copies or compatibles ones dont follow either the quality or spec very well.  While the thread size may be the same many of the Chinese compatible cheap ones dont have a long enough section of thread.

Of course its always possible to fit it incorrectly, especially if you aren't familiar with the process and its quirks.  

RE: Weired droplets and strings

Mh, have to ckeck it. Very good point. Don't remember. Its about 2 years ago I bought these. Will take a look at it. Thanks

RE: Weired droplets and strings

I think you really nailed it. It looked pretty nasty down there when I removed the fan to exchange the nozzle. (See picture)

It was aBrozzl repReap M6 1.75mm 0.4mm Bras. No markings of E3D on the bin.

Reinstalled now the old one I had in there and will see if things improve.

I considered in upgrading my Mk3S anyway to the MK3S+ to be able to run the MMU2 to MMU3 upgrade. Would be a good point now I think.

Leaking from the top: classic result of not snugging the nozzle against the heat break.

Pay particular attention to the diagrams at the bottom of this page:

https://help.prusa3d.com/en/article/changing-or-replacing-the-nozzle-mk2-5s-mk3s-mk3s_2069

It is sometimes the result of careless installation or, as @neophyl says, some 'clone' nozzles have too short a thread and just don't quite reach.

Cheerio,

RE: Weired droplets and strings

Brozzl nozzles (fun to say) are supposed to be decent quality.  However they make several varieties, at least 3 of them use a M6 thread size so will 'fit' in the prusa hotend.  However 2 of them at least have the shorter threaded section (the mk8 and mk10), the V6 though is supposed to be compatible so it might just be incorrect assembly. 

Its easy (if you don't watch for it) to move the heatbreak position while changing if you rotate things, as the rotation causes the treaded heatbreak to 'move upwards'.  Then when you reassemble it can cause a small gap inside where the nozzle and heatbreak dont quite meet and , bam , plastic works upwards and downwards through ther threads, pools on top of the heat block and then drips down.  

RE: Weired droplets and strings

Thanks alot for the support on this.

I think this is exactly what happend. The two diagrams at the bottom of the page were very helpful. Already quite some time ago since I last modified on the printer. Therfore really a good reason to improve a bit 🙂

Thanks