Looks like over extrusion. You should calibrate your steps per mm of the extruder. Or just lower flow rate. Just cut your filament about 120mm above the extruder, take a measurement, extrude 100mm, measure again and lower flow rate accordingly

http://www.buildtak.eu/

Just found this from a local webshop. Anyone tried it? Does it really work?

I know what this is. You are over extruding in comparing to your z-hight. Calibrate your z endstop for more room or reduce extrudin for the firt layer. Try turning the flowrate to about 70% and it should work. When I did some large 250x250 prints with flat bottom I sectioned the bottom to stripes an...

T-slot nuts say item in them.

Looks just like Simplify-3d. Someone copied it?

The needle valve would stop oozing but the filament would stil melt to allmost liquid on the nozle causing some blobs. I've been researching a way to separate the two extruders and dumpin some filament in to some kind of ooze cup before printing again

There are no STL's. The parts are injection molded.

"This upgradekit does not contain any plastic parts. It is assumed you have a DIY kit, where you already have the plastic parts required to do the upgrade."

There are none.

I'm not shure what your problem is. You can change the dimensions in simplify3d freely.