Problem with fast printing infill

I have vertex 2 months, i had printed 2-3kg of filament, PLA only. Two days ago i started getting strange prints. The infill which i’m printing 60-80mm/s became to thick, in results there ware gaps between each layer lines, connect only on crossing spot. The extruder is clicking in that moment.

It seems to be clogged nozzle, i cleaned it 3 time, change ptfe tube twice in isolator and still have the same results. It is very weird on slow speed 30-40mm/s print looks good, but it is too slow. My second nozzle works good all the time, but i used it less time.

I read all topics about similar problems and non of solutions worked in my case. Checked extruder, filter is on the filament, i lowered temperature, i burned nozzle using cigaret ligher and used cooper wire to unclog the end, i disabled retraction (at first day of printing after assembly i have clogged nozzle couse of to big retraction). I try print in different layer hights 0,1-0,35mm and i see problem is capacity, when i put filament by hand it is going very hard, so i suspose nozzle is still dirty, but how can it be clean better? On slow speed i have very good prints without distortion. Filament is good it work well on the second nozzle.

I’m wondering how looks shape of the hole inside the nozzle is it like funnel?

Can’t remember the internal shape, but trying to get rid of burnt matter inside a nozzle can be a huge time waster as it’s impossible to be sure it’s clear until you reassemble it and test it. And then you find it isn’t!

I actually think it’s quicker just to replace the nozzle - they’re very cheap and given the time it takes to clean one, definitely worth getting a few spare.

I think i found a great solution today. I put inside by hand a transparent PLA, nozzle heated to 190C, next i still gently hold down filament and turn off heating. When temperature drop to 100C i release the filament and wait until nozzle temperature achive room temperature, after that i raise temperature to 55C and gently pull up filament it come up with a lot of dirt and it came up in one piece. I found online this method, but with using nylon i think PLA is good to. I made one print after cleaning this method and it is pringing perfect, now i’m using sponge filter on filament and drop temperature to 190C, also first layer. Before i use 220C for first layer and 200 for the rest, but at the beginning i was printing on buildtak, fan on etc. Now i’m printing on blue tape and in 190C it stick very well.

I also check this method of cleaning on the second nozzle and dirt also came out, so i think it is working.