sick copper
Setting recipes by circuit condition is awesome. This little module (12x13, or 9x12 if you decide to cut the water, power, and lab for some reason) builds red and green science from ore and coal by cycling through the prerequisite recipes. It sticks to early-green tech as well (steel furnaces, Assembler 2s, and combinators are the only requirements).
When one ingredient is done (enough for a batch of 20 science) or stalled (neither assembler working for a second and a bit), it cycles the assemblers to the next recipe in the queue, and continues working.
The assemblers input from the middle chest and output to the bottom chest. An inserter passes the intermediate products to the middle, and the cycle continues.
It isn't quite perfectly efficient (the furnaces are at 75% utilization, the power is at ~50%, the lab is only correct for 12s research, and recipe changeovers add ~1% overhead. I didn't do an accurate longterm measurement to see precisely how close it got to the 6.3/min theoretical maximum, but it is over 5.0/min), but it's well within standard tolerances for a normal base.
