The Molecular Assembler
The molecular assembler takes items input into it and carries out the operation defined by an adjacent ME Pattern Provider, or the inserted Crafting Pattern, Smithing Table Pattern, or Stonecutting Pattern, then pushes the result to adjacent inventories.
This assembler has a crafting pattern that specifies the 1 oak log = 4 oak planks recipe. When oak logs are fed into the upper hopper, the assembler crafts and spits oak planks into the lower hopper.
The Main Use Of The Molecular Assembler
However, their main use is next to a ME Pattern Provider. Pattern providers have special behavior in this case, and will send information about the relevant pattern along with the ingredients to adjacent assemblers. Since assemblers auto-eject the results of crafts to adjacent inventories (and thus into the return slots of the pattern provider), an assembler on a pattern provider is all that is needed to automate crafting patterns.
The Molecular Assembler supports the following upgrades:
Optifine breaks the "push to adjacent inventories" function so most crafting setups with assemblers won't work.