Need Help & Advices. Non smooth edges print (1 reply)

I keep getting non-smooth print on the edges / corner of my print.
The attached photo is printed with

layer height 0.3 mm
infill 0.8 mm
standard speed that comes with slic3r 0.9.10b (which I think is already pretty slow)
perimeter is 3
width is set to 0.42 mm
My Steps (X/Y/Z/E) has been calibrated to 50.7 / 50.7 / 2560 / 848

printed with Grey PLA at 185 degree and bed temperature on Mk2a at 60 degree.
(First layer is 190 noozle and 70 bed)

I have tried changing to faster speed and/or with lower infill (0.4), but always got those uneven corner print.

The object in the attached photo is also printed two copies on single run. (I was trying to give it more time before the extuder gets to the next layer, to give more time for the layer to cool off, especially on the layer that has only small area to print). The result is better printing one copy on single run)

I really don't know what else I need to tweak.

My unit is Mendelmax 1.5 with J-Head V hot end 0.5 mm nozzle

Would really appreciate any help/advice.

Thanks
mendelmax 1.5, sanguinololu 1.3a, with NEMA1.7, J-Head V hotend
A4988 Stepstick Drivers