Mystery Black Goo
On occasion the printer has spewed out some a short thing string of black material. Sometimes, it's left some pinhead sized droppings during a print.
But now there's it's left a puddle of black goo. It was hard and brittle when I tried to remove it.
Has anyone seen this?
Re: Mystery Black Goo
I forget to add the file.
Re: Mystery Black Goo
Looks like contaminated plastic. a little bit got stuck in the melt zone and drooped out of the nozzle. Has it just been on that roll of plastic or on all of em? I'd try cleaning out any junk if you got it in your hot end https://www.antonmansson.com/how-to-cold-pull-clogged-nozzle/
Twitter: @firr
Re: Mystery Black Goo
is your heater block tight with the nozzle and the heat break?
I have a Prusa,therefore I research.
Re: Mystery Black Goo
The heater block seems tight.
Yesterday, I had a major print fail and a huge blob formed up around the extruder. I cleared it out, but I haven't been able to print properly since.
And now there's this goo. I was getting these weird black threads in the past, before the yesterday's mishap, but this has become much more pronounced.
I tried another print, and it left another big dropping.
Re: Mystery Black Goo
maybe when you print next you can keep your eyes glued to the nozzle. see if you can find where its coming from. when that happened to me, it was seeping out above the heaterblock. I just gave it a snug and it was good to go.
I have a Prusa,therefore I research.
Re: Mystery Black Goo
Inspect the heater block, see if goo is running down the sides.
Make sure the nozzle isn't seated in the heater block -there should be a gap between the hex and the block. The nozzle should tighten the heat break - not the block. If the nozzle is bottomed out, you'll need to lower the heat break into the block about 1mm.
Re: Mystery Black Goo
does anyone else find the way the whole hot end fits into the plastic of the extruder/hotend housing something of a PITA? the way you have to disassemble the fan mountings etc and the way you have to wiggle the the thing out and then after your repairs wiggle it all back-together again; is one of the design faults that I most wish a talented designer would find a quick and easy solution for. The fix should include the wiring should use a single foolproof locking connector right in the extruder body. the fans should swing right away from the hot end which should be easy to pop right in and out for quick change (switching to a different configurations for different materials) and servicing. the arrangement of the fans now makes it very hard to observe what is happening at the point of plastic. deposition
Re: Mystery Black Goo
I think E3D is working on something like that.
I have a Prusa,therefore I research.
Re: Mystery Black Goo
Well on Tom's VLOG he had a tour of e3d showing the work in progress for a 'extruder head' changing system much like the tool changers on modern vertical milling centers or other machine tool CNC and while it would cover what I am talking about here it would do a lot more and i expect cost a lot. I sort of took this thought over to https://www.facebook.com/groups/prusacommunity/permalink/890257514648315/ where it might get more attention.
Re: Mystery Black Goo
there was something somewhere about a fast change hot end. not the quick change stuff might have been top loading
I have a Prusa,therefore I research.
Re: Mystery Black Goo
if you find info on that do let us know about it
Re: Mystery Black Goo
ill kinda look for it. I moved my printer so.... for gods sake don't move it....
I have a Prusa,therefore I research.
Re: Mystery Black Goo
Ultimaker has such a quick changing printer head, the „Ultimaker print core“. Looking really good but no idea how well it works.
Now that I started changing nozzles I wish the MK3 had such a solution, but that would drive up the costs.
Re: Mystery Black Goo
I ended up heating the extruder, and then loosening and retightening the nozzle and it's been black-ooze free for nearly 48 hours now. I think a gap formed between the heat break and the nozzle.
I didn't think the nozzle was loose, because I tested the tightness of the nozzle when it was cold.
Re: Mystery Black Goo
very cool. ive had the "goo" a few times
I have a Prusa,therefore I research.
Re: Mystery Black Goo
does anyone else find the way the whole hot end fits into the plastic of the extruder/hotend housing something of a PITA?
100%. Hard to get the angle correct to ease the PFTE tube in or out without slight bending.
Does sound like the OP has a partial clog happening that is gradually working its way out.
A cold pull may help clear.
Re: Mystery Black Goo
I ended up heating the extruder, and then loosening and retightening the nozzle and it's been black-ooze free for nearly 48 hours now. I think a gap formed between the heat break and the nozzle.
I didn't think the nozzle was loose, because I tested the tightness of the nozzle when it was cold.
You may have fixed the issue. I was going to suggest a loose nozzle as a source of the leak. It should be tightened when it is hot. Plastic oozing out will form around the threads and harden when it is cold. This might make it seem like it is tight when it is actually being held in place by a lump of goo.
You may need to re-adjust the first layer height if you tightened the nozzle.
Steve