Need help to root cause these printing defects

Set up is,
Mono Mendel, 0.5mm nozzle, 1.75mm PLA, hot end temp at 190C, heated bed at 45C for first layer & turned off for rest of the layers. Hot end is bowden feed.
Extruder, all axis and motor current are calibrated. Have even connected external fan for cooling stepper drivers.
Print settings were,
speed 60mm/s, 1.5mm retraction, Retraction speed is 5mm/s, 0.3mm layer height, 0.5mm first layer height.
Print object is
[www.thingiverse.com]

Have attached 2 snaps of the finished print, 2 different angles.
The issues are,
1) There are some de-formalities on one/two side of the hexagon at top layers, rest of the print looks fine. Can be seen in snap named "Defective side"
2) When the printer finishes one layer and jumps to next, it leaves kind of a blob at transition point (area marked red in snap "better side")

Appreciate any kind of inputs

I can only guess about the deformities, how many outer/top layers do you have? If you only have one than the heat pockets created will actually expand and burst your outer layer. It's at an angle so it would close sections of infill with warm plastic, heating the trapped air.
The blobbing, however, may very well be from your 5mm/s retraction speed. I have my retraction rate at 100mm/min and at 3.2mm of retraction. I have a Solidoodle so I'm sure you would have different numbers, but that should give you an idea. When it changes layers the retraction takes time, if it's slow enough it will work against itself by allowing it to ooze rather than pulling it back.

Edited 1 time(s). Last edit at 04/05/2014 04:37PM by MrDoctorDIV.

Do you have the fan blowing on just one side? I recently added a fan to the left and right of my hot end because of an issue like yours, but not that extreme.

Blowing all around, circular ring around the nozzle.