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Extrusion blops at print start  

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Astroprinter
(@astroprinter)
Eminent Member
Extrusion blops at print start

Hi,

I always have the issue that during preheat and in particular during mesh bed levelling the nozzle oozes filament that forms a tiny blop around the nozzle. Unless it gets dispatched during the initial priming print in the priming area, it eventually ends up somewhere on the first layer and often causes the first layer to be contaminated and the subsequent layer failing. IMO, there would be a more thorough wiping action in all directions required before starting the first layer.

Is there any remedy in place for this?

--
MK3

Opublikowany : 04/04/2020 11:28 am
Neophyl
(@neophyl)
Illustrious Member
RE: Extrusion blops at print start

You can do a 2 stage start by editing your start gcode and saving it as a new printer.  Many of us do this to preheat the pinda probe which makes bed levelling more consistent.  

Bob has some very good  notes on how to do this here http://projects.ttlexceeded.com/3dprinting_prusaslicer_gcode.html

Basically you preheat the bed , and also the nozzle to around 160-170.  By preheating to this the filament is soft enough that if it does hot the bed it wont damage anything and its cool enough not to ooze and leak.  Move the extruder to above the bed so that it can heat the pinda probe.  Waits till the pinda probe is at 35 degrees and then it does the mesh levelling.  It then goes to full temp and prints the purge line as normal.  

Opublikowany : 04/04/2020 2:59 pm
Astroprinter
(@astroprinter)
Eminent Member
Topic starter answered:
RE: Extrusion blops at print start
Posted by: @neophyl

You can do a 2 stage start by editing your start gcode and saving it as a new printer.  Many of us do this to preheat the pinda probe which makes bed levelling more consistent.  

Bob has some very good  notes on how to do this here http://projects.ttlexceeded.com/3dprinting_prusaslicer_gcode.html

Basically you preheat the bed , and also the nozzle to around 160-170.  By preheating to this the filament is soft enough that if it does hot the bed it wont damage anything and its cool enough not to ooze and leak.  Move the extruder to above the bed so that it can heat the pinda probe.  Waits till the pinda probe is at 35 degrees and then it does the mesh levelling.  It then goes to full temp and prints the purge line as normal.  

Excellent! Thank you very much for that reference. I used to preheat the PINDA probe, but abandoned it recently due to the before mentioned blob problem. I'll try this now.

Thanks again!

--
MK3

Opublikowany : 04/04/2020 5:13 pm
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