Problem with instant clogging on brand new printer
I unpacked my new Ender 3 Max, assembled, updated the firmware to latest Marlin (TH3D) and leveled the bed.
As with any new printer my first print was a Benchy. Running on the sample PLA filament that came along with the printer. When reaching above the deck and starting to print the pillars (see pic) the extruder "clogged". I say "clogged" because what seems to happen is that while retracting the filament expands and cannot go down the nozzle again. Pulling out the filament, cutting the end of it and feeding it back in the printer makes it work again.
I tried this benchy three times so far. Two times on the included sample filament and then I tried a spool of my own that I use on my other printers. This one came a little further but then the same thing happened.
I've used prusa slicer with the included Ender 3 PLA profile. It was set to 215C for the nozzle and 75C for the bed. Retraction is 6mm at 60mm/s. I used these settings for the first print and reduced the temperature to 200/60 for the next two prints.
What I've read online the Ender 3 Max runs great on the default profile in prusa slicer so I suspect something is up with my printer.
Possible problem I've found online (besides the normal ones that apply to any printer) have been units shipped with broken hotend fans jamming specially PLA prints. I can't tell if the fan is "as it should be" but it sounds normal and is spinning. Retraction in my opinion seems reasonable at 6mm for a bowden system although I might try to change this to maybe 4mm just to try. The retraction speed I'm thinking of trying to increase dramatically in hopes that it will "pull" the hot filament which could maybe "strech it" so it stays thin (This is just a theory of mine without any proper background or experience).
I've never had these problems on any printer before. Although this is a new unit and as far as I understand it should not have these problems with the settings provided by default in prusa slicer.
Advice is much welcome!
Attaching two pictures. The benchys and one of the filament "clogges" that I pulled out the printer.
I've printed two benchys now in PLA without clogging by reducing retraction to 4mm and the retraction speed to 25mm/s. I am getting some stringing though. Trying a PETG print ATM to see how that performs using the same reduced retraction.
What retraction settings are you guys using on your Ender 3 Max printers?
The PETG print did not finish well. It stopped too cause of clogging but it did not reach the dock of the benchy. This with the reduced retraction settings that worked for PLA :'(
I might have figured it out actually. My extruder is obliterating the filament and when printing details with lots of repeated retraction it crews on it many many times eventually creating a small bend of totally mushed filament and then the extruder starts to click (what I've thought was clogging). When I have pulled the filament out, cut off the tip and feed it back out has been enough to feed this badly beaten part of filament into the Bowden tube, hence working again. I've now tried to release the tension on the extruder but even at the loosest setting it is a quite strong grip. If this does not work I'll try "retraction count" or "min extrusion before retraction" (depending on slicer) to avoid crewing on the same part of filament over and over. Printing now with the screw at the loosest. I'll be back with results.
Clean the hot end by clearing the holes, melt the the obstruction, use a lighter. Then assemble it again and now make sure try pushing the bowden tube further down. It solved my issues of clogging.