I’ve had loads of those tubs as we feed birds too, but never thought of using them for the filament….
I have one of these I can vouch they are awesome
Yeah man, worth every penny especially for TPU.
Have you tried reducing the filament speed?
Also the retraction settings maybe a bit low.
I found that only minor tweaks can make the world of difference.
I would also say 255 is too hot.
My go to for PETG is a starting point of 230 increase the retraction settings my 10% and slow down filament speed by 14% over pla.
I don’t have an ender 3 so my settings are probably going to be way off yours.
I use Sunlu PETG I have used HK PETG and had the same results but my absolute favourite and go to is Eono. I have only had a couple of failed or blobbed out prints stince it started using this.
The settings were the same except for a 250 starting temp for 3 layers then back down to 230.
Hope this may have been of some assistance.
You may have a damaged ptfe throat too? They don’t last for ever and can cause uneven extrusion.
I have been pricing up all metal hot ends. I can go for broke and get a Micro Swiss direct extruder and hot end for £100 but I need to get the basics right first before shelling out loads of money. And I also need to actually land a job, Everything I have been put forward for has ended with me be released, sometimes only a day before covid test and fitting. At least I have some Christmas bookings - as long as there is fuel available to get to them 
The consensus seems to be that I need to dry my filament and store it in a drybox so that is the first thing I will try. Came across this which I am pricing up for a home-made job:
Thanks for the advice. I have tried at various speeds and temperatures. It’s difficult to sort at the moment because the print shifts layers due to the blob problem before I can get enough of an idea of what the rest of the hassles are
New all metal hot end, PETG at 235 degrees onto painters tape, bed at 85, good adhesion. New belts X and Y, all axes adjusted for minimal play. Laying down a raft - first layer lines are even width and looking good:
Then, a little later it has spewn out a gobbet of what looks like burnt filament. Any ideas before I see if @callum will lend me his 3D printer boots?
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It looks like you’ll have to baby sit a print to see where it’s oozing from.
If you were to remove the cooling shroud, you might be able to setup a camera. It might be the only way to find out where or what is causing this.
How much plastic was sticking to the nozzle as this maybe an indicator of over extrusion?
If over extruding, the filament builds up around the nozzle and may take quite some time before catching and peeling away from your nozzle.
The picture shows a good length of print time before the blob, which leads me to believe it’s “extrusion” related.
Play around with the extrusion multiplier, reduce the % to around 89% but you may need to lower the hot end by maybe 0.1mm.
I know all printers are different but this is how I’ve set mine up from cold.
Nozzle 0.4mm
1, Cold Bed to cold nozzle gap; feeler gauge gap 1 thousandth inch.
2, Primary layer height 0.1mm
3, Extrusion multiplayer 0.88.
4, first layer height 120%
5, first layer with 100%
Select a small model to print, print with 5 or more skirt outlines about 25mm away from the model.
Stop the print before it starts on the model, look at the outlines, are they squeezed and flat, too far or are they too round and floating on the bed.
If too flat and squeezed or too rounded and floating raise or lower the nozzle via the ‘Z’ axis’s offset in the printer, repeating this until you’re happy.
might work for you….
Here’s a print following the above procedure.
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‘Z’axis in the slicer not printer……oops
Thanks for the info. I have temporarily retired the printer and fired up a recently acquired Geeetech (three “e’s”) A30T which has three extruders - so should be 3 times more reliable more trouble The stock mixing head which allows colour gradients has been replaced with a BigTreeTech 3 in ! out hed to allow colour change layer by layer. I got the thing because it was the right money and has a 320x320x400 build area.
It’s made a nice job of a calibration cube so I have set it to print a self designed ESC holder for my octocopter while I give the Ender 3 Pro a severe talking to. I will basically rebuild it so that I am happy with frame alignment on all axes and that everything moves without binding anywhere. I am also replacing the stock extruder with a direct Aero style job. Then a lot of testing to make sure it works: )
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