The Steam Workerbot is the most expensive workerbot resource-wise and requires logs to charge, but has better carry and inventory capacity compared to the Basic Workerbot. It also has the ability to charge itself if it has logs or other wooden items (see below) in its inventory when it runs out of charge (but cannot refuel itself if it's only carrying the items). Otherwise, you or other workerbots can refuel them by right-clicking them while carrying one of the wooden items.


In a WorkerAssemblyIcon Worker Assembler, you can make a SteamWorkerbotIcon Steam Workerbot by adding:


The following items can refuel steam workerbots:

Item Energy Energy per Log*
Stick 10 n/a
Pole 20 720
Plank 60 360
Log 120 120

* if you're using a Bench Saw

Since you can only fuel steam workerbots when they have run out of charge and only one item can be consumed at a time, only logs can fully refuel steam workerbots. Thus, if you're using anything except logs, the workerbots will be less productive over time due to having to refuel more frequently in addition to spending more time in a low-energy state (which reduces their movement speed).