Auto Splitter Block
A Factorio MOD that automatically sets splitter output filters to block the unused side when only one output has a compatible transport entity.
Features
- When a splitter has a transport entity on only one output side, the other side is automatically blocked using an output filter.
- The filter is cleared when both outputs become occupied or both become empty.
- Responds to placement and removal by players. Optionally also by robots and space platforms (disabled by default).
- Re-evaluates the block filter when a splitter or its output-side transport entity is rotated or flipped.
- Splitters with user-configured filters or connected to circuit networks are left untouched.
Block Filter Item
The item used for blocking is configurable in MOD settings (startup). Default: No item.
Additional options with optional MODs:
Automated Builds
Entities built by construction robots or space platforms are ignored by default, to avoid overwriting filters set by blueprints (e.g. balancer designs). Space platforms have no manual placement — all platform construction goes through this same automated path, so enabling this is the only way to get auto-blocking working there.
Enable "Enable for automated builds" in MOD Settings > Map when needed, and turn it back off afterward. It's a single value shared by the whole force, not a quick toggle button, because flipping it also affects any other robot construction in progress elsewhere on the map.
Compatible Transport Entities
- Transport belts (same direction or sideloading, but not opposite)
- Underground belts (inputs: same rules as transport belts; outputs: sideloading only)
- Splitters (same direction only)
- Loaders (same direction only)
All tiers are supported.