Geeetech prusa i3 pro b - problems with layers 1 and 2

[stubaby49]

The (hopefully) enclosed image show 3 examples of a test specimen which is 2cm in diameter and 2mm thick. The upper disc shows the base, the middle disc shows the edge and the bottom disc show its top.

2cmDisc_sml.jpg (645.87 KiB) Viewed 6233 times

The problems I have are ..
1) The strands on the bottom lay are not fused together and the outer strands often become loose.
2) The outer layer of the second layer becomes rucked and does not lay flat.
I am happy with subsequent layers and the top of the disc.

I am extruding PLA.
I have used bed temperatures of 55, 65 and 73 degrees C.
I have used extrusion temperatures of 200 and 210 deg. C.
I have varied the 1st layer thickness from 0.25 to 0.35 mm (gap physically set using a business card to level the bed). Subsequent layers are 0.2mm.
These changes have little or no effect,

Has anybody had a similar problem?
Can anybody suggest a solution?

Thanks in advance.
Stuart

[William]

A wiki you can refer to :
https://www.geeetech.com/wiki/index.php ... ting_Guide