Cura - fine setting - no bed adhesion

wolph42

Concerns the jgaurora A5. When printing 'draft' in cura 0.2mm, it works great and I get the quality that fits the description. 

IF however I change the setting to fine I no longer have bed adhesion. The first 5mm or so are thick and stick and then the extruder starts to underextrude a very thin stream of filament comes out or nothing at all or blobby (thin/thick/thin/thick, etc). This while I have the initial layer setup EXACTLY the same as with 'draft' . Does anyone know whats going on?

the slicing is done with the latest version of cura and witht he jgaurora settings from the wiki. 
I've:
- lowered the speed
- increased flow
- increased thickness of 1st layer
All render the same result: 5mm goes well and then it gets thin and is dragged along with the nozzle making a mess.

Other usefull stuff:
-PLA
-bed 60C
-nozzle 200C
-flow: 110/100/90% (tried them all, 90 is the one I use for 'draft' as that yields the right result). 
- speed: gone as low as 5mm/s for brim: (also tried faster) no change

DaHai

Sounds like you're printing too cold and the nozzle is clogging. 
You're getting extra heat off the print bed below 5mm so it keeps the filament warm and flowing. But above that you loose that effect and so between that and the part cooling fan, the filament is not hot enough to extrude.
try increasing hot-end temps by 5 - 10c

wolph42

Thanks. Its weird though. I left this alone for a while and started doing  cone tests for stringing. There's a LOT of stringing so I started to increase retraction speed (upto 20) decrease flow to 80% and lowering the temp to 180C (over several tests). The stringing decreased significantly and most of the 'blobbing' effect I had disappeared as well. So its going in the right direction, however there's STILL stringing and I'm a bit hesitant to further lower the temp.

As for finer setting, I changed the approach initially I used the preset and then changed stuff back to what I had in coarse (which resulted in very little extrusion). This time I took the coarse (0.2) setting and changed that to 0.1 and halved the speeds. 
That worked, so I got extrusion, however stringing yet again increased significantly .

Should I go down to 170C ?? that seems awefully low. I also noticed that the bedadhesion is a bit flaky and the brims have holes in them, indicating a too low flow, which is weird as that is set to 100% (vs the 80% in the layers above) AND at a higher temp (200C) to make sure it sticks. 

Another issue I had is that during the night I had a print of many parts and this morning I noticed the brim had come loose (ruining part of the print). At closer inspection I noticed that the brim came loose because one of the parts was 'knocked' out of place (apparently by the extruder) as it was clearly ripped from the bed. The weird thing is: this was not on the edge but more to the middle . Any clue how that could have happened?