[help with settings to fix print quality]

I am having issues with prints delaminating and being very weak (PLA prints feel soft and spongy and are easily crushed by hand).

See the attached image for examples. the 3 prints to the left were stopped after the first layer due to clear gaps. The one on the right was allowed to continue but was ultimately a mess.

 

My first mistake is too many variables changing: I lost my cura settings, have a new brand of pla filament, and have also recently leveled the bed.

 

I'm not sure if it is a case of poor quality filament or some settings I have lost in cura.

 

I'm hoping that soomeone with experience can take a look at the attachment and be able to advise what is causing this? Is this just a case of underextrusion or something else at play?

 

What I have tried:

- changing temperature up and down (200 to 220 degC). doesn't seem to help but ther is stringing at the temps tried

- levelling bed - tried with small gap between nozzle and bed and a slightly larger gap

- change filament diameter in materials screen (filament measures 1.70mm with calipers)

- change flow rate to 115% and 140%

 

Machine: Creality ender 5

Material: Sunlu black PLA 1.75mm

 

 

Can someone point me in the right direction of settings to tweak in cura to try and fix this?

 

Thanks