TLDR: drop a single item in the belt that has two green wire connection (in the length 6 loop) for each autoforester, drop 10 sapplings in a chest and 3 in the next one and you're ready to go.
A tree farm where you each auto forester does not take more than 13 seeds at a time, allowing you to get near the most out of a limited number of seeds, with minimal manual intervention. It does not use a single combinators and thus does not require even a single drop of iron, so you can start it very early (the earliest the best). Due to bluprinting giving wires for free, you can even build it pre green science.
It uses a belt based three state sequetial automaton (like a RS latch but with 3 metastable states in stead of two), and I guess you can reuse this idea for other mods adding cyclic recipe with an ingredient hard to kickstart.
The states are read on belt segments with green wires and changed by activating belt segments with red wires (unlike combinator based latches, the control signal needs to last some times to be effective). The 3 states are:
- filling: which enables the inserters filling the chest buffer. When the chest contains 10 items, the automaton moves to the next state
- emptying: which enables the inserter emptying the content of the buffer chest into the autoforester. Moves to the next step when the buffer chest is 0.
- waiting: does nothing. Moves to the next state when the auto forester finishes a cycle, detected by wiring the output inserter.
Notes:
- a burner inserter (in Industrial Revolution at least) can swing exactly ten times before requiring more fuel, so you don't actually have to prime any of them with fuel (the critical ones are the ones feeding the seeds, which you will see blinking in red during the first cycle of their machine.
- although it does nothing, the waiting state is needed because the output inserter takes very long to unload an auto forester, and would set the latch back to filling before the buffer is actually emptied.
- some saplings are stuck in splitters. Autoforester feeding his neighbour rather than it-self is an attempt to mitigate that. Up to 3 saplings per forester will eventually be stuck, but a front of 13 sapplings will never stop running.