bad print in "special" locations

Hi,
Setup: I have a kossel mini delta printer.
filament is calibrated & axes as well (at least this was what I thought).
When I tried to print "large" thing I got a very bad start in every configuration I've tried (till now).
There are 2 major issues in the attached picture I would like to get advice about:

1. There is less filament in those areas compered to others - moving my finger on it seems like no filament at all in that section.
2. Filament didn't stick to surface while filling the inner part (100% fill this time but it was the same with 50% or less) - I've checked the location with pronterface & it does pass the paper test so what is wrong?

I've been able to print small parts so I assumes I need to learn some more

Please advice..

I would try moving your z up a bit, looks like you may be tooo close to the bed.

Thank you for your replay.
When you wrote about moving Z up did you refer to part a only or to both?

I'm less concern about the a problem & much more about the b problem...

Raise the hotend so it is not so close to the bed for the first layer.

I agree, it looks like your Z axis is too low and causing both problems.

Thank you both, I'll try what you offered.

I'm sure you have more experience than me so could you kindly explain me something?
The Z axes is as you assumed close to the a.
The b mark was created while hotend moves in diagonal from right to left downwards (towards X axes) in this movement the hotend goes away from Z axes.
If Z axes is too close I would have expect that such movement will break when it started closer to the Z axes but both b section occurred when moving towards X axes.
So.. what am I missing/wrong in my assumptions?

Edited 1 time(s). Last edit at 12/14/2014 02:48AM by polkary.

So in general you need to move your Z Axis aka print bed down. So on a delta it's a little more complicated. Without actually seeing the print bed, not sure if I can help much. So the autolevel thing can cause some issues, if that is what your fighting. There is probably config setting that would help. But whatever method you use, I would use the trick of leveling it with a sheet of paper on the bed then when you start printing pull it off it gives you the little extra space you need for the print. At least my autolevel tests always seem to make it print too close to the bed so using the paper trick always makes it print better.

So I this guy's video helped me allot too. LINK

Forgot one more thing, if your using Sic3r you can change the Z offset on the printer settings tab; increase the value from 0 in .05 increments.