How Ducts Work
Three pieces and no logic: a pipe, a Loader that empties a box into it, and Ports where things may enter. Items find their own way.
A duct is a run of pipe. A Loader bolted to a container empties it into the run. Every container a Port marks as an entrance receives, and where an item ends up comes down to one rule:
A container that already holds some of it wants it more than one that doesn't.
That's all the sorting there is. Put one plank in the plank chest and planks find it from then on. A Port's filter overrides the guess where being told is better, and an unfiltered chest with room in it catches whatever nothing else claimed.
Speed
| Duct | Cells per second |
|---|---|
| Wooden Duct | 3 |
| Glass Duct | 3, and you can watch items go by |
| Reinforced Duct | 5.5 |
| Metal Duct | 7 to 14, from the ore's Hardness |
The slowest length in a run sets the pace for the whole run, the way the narrowest pipe does.
There's deliberately no signal, no delay and no state to reason about. This stays pipes, not redstone.