Balls of Filament after changing nozzle
Hi,
I'm getting some very weird filament balls printing with my Original Prusa i3 MK2S. These are not the normal ones I see other people talking about - see a picture here for a sample of some of them.
Here's a timeline of how they started happening:
1. I did a large print (spiral chess pieces from Thingiverse) in black. The print finished overnight and everything turned out amazing.
2. The next day I went to start a print of some puzzle board pieces (also from Thiniverse) using the same filament. The print failed miserably as the brass nozzle clogged badly. However, lucky for me, my Olsson Ruby nozzle arrived the same day.
3. I replaced the clogged nozzle with the Olsson Ruby, did a thorough calibration, and started the board pieces print again.
4. I noticed several blobs of filament (round and shiny) being dropped onto the print, especially into the infill. These blobs would often impact the pieces. I would knock them out of the way as soon as I noticed them. Sometimes they were stuck onto the print and I couldn't remove them.
5. Today, I unloaded the black filament and switched to a green filament to print out some page holders.
6. Interestingly, shiny, smooth black blobs of filament are falling off the head periodically. I have no idea where they are coming from.
Any idea where these BLACK blobs are coming from while I do a print using GREEN filament?
David
Re: Balls of Filament after changing nozzle
Tighten your nozzle !
This must be done by heating the extruder. There is some leakage now.
Thomas
Re: Balls of Filament after changing nozzle
the black stuff is carbonized filament.
as Thomas already mentioned: your hotend is leaking, after changing the nozzle.
changing a printers nozzle isn't just unscrewing the old one and screwing in a new one !
you have to do this at the highest temperature and absolutely "watertight".
have a look at tom sanladerer's video about choosing and changing the nozzle.
if you've problems to get the mentioned copper paste, go to a car diy-shop... they usually sell this stuff for treating the threads of an exhaust manifold before tightening the bolts.
dem inscheniör is' nix zu schwör...
Re: Balls of Filament after changing nozzle
Thanks for the suggestions!
I ended up pre-heating for PLA, removing the Olsson Ruby nozzle, then setting temperature to 295C (highest I could go) and then reinstalling the Olsson Ruby nozzle. I had quite a bit of trouble reinstalling the nozzle because it was either far too hot to hold by hand or hard to get the threading right using needle nose pliers. Since I recall no such difficulties the first time around, I must have installed the new nozzle cold (or cooler) or possibly the cold pull I did against the old nozzle, trying to remove the clog, helped.
So far, after printing a few different items, things are working great and I haven't seen any new carbonized filament balls!
The only thing that I would do differently next time is a cold pull prior to removing the old nozzle.
Re: Balls of Filament after changing nozzle
Thanks for the suggestions!
I ended up pre-heating for PLA, removing the Olsson Ruby nozzle, then setting temperature to 295C (highest I could go) and then reinstalling the Olsson Ruby nozzle. I had quite a bit of trouble reinstalling the nozzle because it was either far too hot to hold by hand or hard to get the threading right using needle nose pliers. Since I recall no such difficulties the first time around, I must have installed the new nozzle cold (or cooler) or possibly the cold pull I did against the old nozzle, trying to remove the clog, helped.
So far, after printing a few different items, things are working great and I haven't seen any new carbonized filament balls!
The only thing that I would do differently next time is a cold pull prior to removing the old nozzle.
the problem with this procedure might be that there will be some remainders of (old) filament left in between the threads of the heater block.
furthermore you need to make sure that the nozzle "kisses" the heatbreak inside the heater block, to seal it "watertight". otherwise sooner or later some leakage through the threads of the heater block will occur, either under or above the block.
dem inscheniör is' nix zu schwör...
Re: Balls of Filament after changing nozzle
Also after the nozzle is heated, shut the machine off. You don't want to be holding the heater block with a wrench with power applied to the heater. The wrench can slip and touch the exposed wires. The nozzle won't cool down that much in the time it takes to install the nozzle.