Bubbling at the Top Layer- Makerbot 2X

Hi, when I print something on my makerbot 2X it always bubbles at the Top.

Here is a Image of the Bubbling: https://postimg.org/image/cpy7e3vm3/

Here is a video of it making a item: https://www.youtube.com/watch?v=Ae4NjKFCE8w

Infomation: Filament Type: ABS
Printer: Makerbot 2X

I need someone to reply as soon as possible, I am showing my 3D printer at this place and I need to get this problem fixed by today because if i don't it will cost me a lot of money so please reply as soon as possible. Thank you!

You're problem is due to the plastic not bridging the gap of the infill without sagging. There are three things to try:

1) More cooling to bridges gaps better.
2) Denser infill so the gaps are more narrow
3) more top layers to make up for the deficiencies in the first few top layers.

2 and 3 are sure-fire solutions, but they'll extend print time and use more plastic.

Slow down your bridging speed. You are printing at quite high speed, so the material is not cooling in time to gain enough rigidity as the head moves.

Try halving the bridging speed.