Blobs and underextrusion after headlift with 0.5mm nozzle

Hi, with my self-modified nozzle I’m having problems printing my object. I need to print objects with about 10 headlifts per layer and each section is a thin wall (just two perimeters).

I see it leaves a blob after retraction, and an underextrusion of about 2-3mm when restarting.

Do others have this when using a larger then stock nozzle? Maybe my problem is caused by imperfect surface finish or the nozzle not being drilled perfectly round whole (hand drilling with dremel)?

I’m trying different slicer settings like ‘wipe on retract’ and ‘extra filament after retraction’ to compensate but no real success yet.

Is this a consequence of using larger diameter nozzle?

thank you

while i was writing this post, I was trying the ‘wipe on retract’ function in SLIC3R. Turns out this works fairly well, it wipes the nozzle for about 8mm on the ongoin perimeter before moving on to the next one. I see a vast improvement, 90% less spider webs and blobs…

Now experimenting with the ‘extra extrusion length on restart’…

[quote=“TLS”]Is this a consequence of using larger diameter nozzle?[/quote]I’d say yes. It’s oozing a lot more than a smaller nozzle.
You should increase the retraction.

[quote=“TLS”]Now experimenting with the ‘extra extrusion length on restart’…[/quote]And that too.