Filament going down after prehot hotend
Hi all,
this is my first post.
I was very happy when I received my prusa MK3 kit, it is my second 3D printer (the first one is a Clone of the I3).
I assembled it in one night and every things were fine.
I printed a lot of things with the extruders original parts received with the kit without issues.
I builded the "ikea" enclusure to improve the printing with ABS.
When I saw the new extruders parts (R3) that they have a little improvment with the TPU filament printing, I printed all the new parts and I assembled them.
Now I have a lot of little ussues, the first one is the filament going down when I prehot the hotend, when the hotend reach the temperature (for example 215 with pla) the filament going down from it about 15- 20cm and I need to cut it before printing... so as you can imagine what can happens on the bed when the printer start the printing...... filament everywhere....
I tried different temperature...changed PTFE inside E3D6... and reduce the height of it of 1mm to prevent the interference with the extruder motor.
The second issue is a lot of webspider on my printed objects...
Now I'm here to ask your help....
I tried everything I could ...
Thank you
Sandro
Re: Filament going down after prehot hotend
These are some photos of my issues
Re: Filament going down after prehot hotend
Mine always oozed 10-20cm when it heated up, with PETG anyways, dont remember it being an issue with PLA but the only PLA i have printed was the included spool from prusa.
Is this not normal behavior?
Re: Filament going down after prehot hotend
I don't remember this problem on my first printed parts with old extruder parts B6.
Anyway if you can't cut the filament after the "extra filament", I think that you find some issue when the printer start print, it is correct?
Re: Filament going down after prehot hotend
I don't remember this problem on my first printed parts with old extruder parts B6.
Anyway if you can't cut the filament after the "extra filament", I think that you find some issue when the printer start print, it is correct?
The purge line done right before the print starts usually clears out the ooze in about 70% of the time ive found, I have successfully stared prints remotely with octoprint and had it work out fine but this is not an ideal situation because sometimes parts of the ooze will fall on the bed during the 9 point bed leveling and cause minor issues with your bottom layer.
Re: Filament going down after prehot hotend
I agree with you... but I have also octo and I'm not confident to start remotly a print, currently I prefer to see what happend because with old parts (B6) I didn't have so much filament out from hotend.
I think that after any print the temperature of e3d6 going always down but something continue to push the filament that obviusly don't go out for a low temperature ... and... when I pre heat the hotend, the filament (previusly pushed from something) go out at the correct temperature.
I'm thinking to change again the extruder parts with the old ones and see if the issue continue, I suspect that the issue is on the position of the Bondtech pulley of the extruder his axys Y is a little bit to the right and the motor that remains on this position continue to push the filament.
In fact, if you cut the filament-->reset the printer--> wait the temperature going down--> re heat the extruder-----> the filament don't go down.
on all these phases the motor is stationary (I'm thinking also on the new firmware now 🙄 that at the end far of any print don't retract the filament )
For the web spider... my only think is on the extruder temperature... but I changed it with different and I had othres problems on the print.
Re: Filament going down after prehot hotend
I'm thinking that when you preheat the nozzle with plastic already in it, the plastic expands as it heats. It has to go somewhere and it can't go up since it's braced against the gears, it has to ooze out the nozzle. Mine definitely oozes worse if the color I need is already loaded when I heat it up, if I do a color change then sometimes it doesn't ooze hardly at all, even while bed leveling. I never tried to cut it off, I just snatch it out with my fingers if it's long like the pic or I use a clean, folded paper towel to wipe the nozzle a second before it descends to start the bed leveling.
Somebody had posted a start code to reduce oozing?