The Mass Fabricator takes a total of 1,000,000 EU to create 1 mb of UU-Matter. When the Mass Fabricator is supplied with Scrap or Scrap Boxes, the power inputted is essentially multiplied by six. It takes thirty-four pieces of Scrap (or 4 Scrap Boxes) to make 1 mb of UU-Matter, effectively making a piece of UU-Matter cost approximately 166,667 EU.
The top slot in the Mass Fabricator GUI is the Empty Cell input slot; cells to be filled with UU-Matter will be taken from here. The bottom slot in the GUI is the cell output; filled cells of UU-Matter will be put here. The middle slot in the GUI is the scrap (box) slot; scrap and scrapboxes may be placed there to amplify UU-Matter generation. The tank in the middle of the GUI is for the generated UU-Matter to go if there are no cells for it to go in.
While operating, the Mass Fabricator will use as much EU as it is provided. Care must be taken to prevent the Mass Fabricator from taking all the EU generated on the power grid, as it will leave no extra for other machines.
The Mass Fabricator can handle up to High Voltage Energy; any more than 512 EU per tick, however, will cause the machine to explode violently.