Flashforge Dreamer 1st week problems

Hey Guys i just got the dreamer as my first 3d printer
i have been testing and i have made half a dozen prints small just for testing but
they all have the same problem around 1/4 of the print there is always deformation or holes
i have tried using flashprint and also simplify 3d but they have the same problem hopefully someone here
knows a way to fix this i use abs extruder 220-230 platform 105-110 fan off 100 microns
what i dont understand is that for example if my print has 300 layers 1-50 are great and 50-80 have the problem and
after that 80 to 300 is great again hopefully someone will help Thanks in advance

http://i67.tinypic.com/2lt23oi.jpg
http://i67.tinypic.com/3502yxj.jpg
http://i66.tinypic.com/1he8ew.jpg

fan off - that right there is your mistake.

apart from nylon I have the fan on all the time. Amazing how much difference it makes - particularly with abs.
The issues you have are with the steep overhangs, the fan will really help here as it hardens the plastic as it's being extruded into space.

what's happening with your is the plastic is extruded partly in midair, that part stays hot and sags, which effects the next layer and and so on.

The fan can't stop this entirely, but does make a huge difference.

If i add more supports will it fix it ? or does it have to be another fan?