PVA keeps clogging BB0.4 core after 30min to 1h of printing

[ACDCC 0]

Hi,

 

Like it says in the title. After an hour or so of printing the core clogs. The first layer is ok but after it goes to standby once it doesn't start again. it's clogged, burned in.

if some PVA comes out of the extruder is yellow and brown. I cleaned the core 3 times today and the cleaning filament on the first cold pull was brown.

I dried the filament on the printer like it says in the PVA manual (on 55C for 2h) , but it didn't change anything. I reduced the standby temp to 50C but when i monitored it the nozzle temp got down to 200C and it was time to heat up again(it went down slow). I set the printing temp to the minimum and it was the same.

Next i plan to set nozzle switch retraction distance to something like 80mm and speed this up by 30%.

 

Does anyone have any other suggestions or has tried something else and it worked (or didn't so i can skip it)?

 

The print is 1d19h long. The first time this happened 20h in. I don't have a filament drier yet.

 

 

Hope to hear your opinions and advice.

Thanks.