Factorio Forums

I'm trying to setup a circuit where the biochamber crafts whatever signal is sent to it. This works pretty well for most of the time. If I send it a plastic signal, it picks the bioplastic recipe which uses mash and flux. It doesn't pick the chemical plant recipe which uses coal and petro gas. I expected the same behavior with rocket fuel. I expected the biochamber to default to the rocket fuel from jelly recipe. It doesn't. I defaults to the assembling machine version that uses light oil and solid fuel. It seems more consistent to me to use the biochamber specific recipe as the default. (Also, this makes my gleba setup work, lol.)

That is not a bug, if you send an item signal it will set a recipe that produces that item, nothing more.

Loewchen wrote: Sat Feb 07, 2026 5:09 pm That is not a bug, if you send an item signal it will set a recipe that produces that item, nothing more.

Right. But I think it's picking the wrong recipe. There are 2 ways to make rocket fuel. There are also 2 ways to make plastic. If I send a plastic signal, the biochamber uses the biochamber-only plastic recipe. If I send a rocket fuel signal, I assumed it would do the biochamber-only rocket fuel recipe. It does not. Instead, it uses the assembler style recipe. This seems inconsistent and unexpected.

Again, it is supposed to set a recipe that produces the item and it did. If you want it to do something else you can make a feature request.