Shaft Power is the form of energy used in RotaryCraft. Unlike other power systems that primarily utilize electricity, RotaryCraft uses rotational kinetic energy from connected Shaft blocks. Shaft Power has three important factors:
- Torque, the force with which the shaft keeps turning. Measured in Nm.
- Speed, the rate at which the shaft turns. Measured in rad/s.
- Power, the rate at which energy is transferred, equal to the product of Torque and Speed. Measured in W.
All Shaft Power math is based on multiples of 2.
Shaft Power is generated by Engines. Each Engine has a known Torque it outputs and a known Speed it outputs it at, which combine to form the known total Power the engine outputs. Likewise, all machines that consume Shaft Power have certain minimum Power requirements. Most machines require a minimum of two of the three factors, and if those minimum requirements are not met the machine will not run. In RotaryCraft, having an insufficient Speed or Torque to run a machine is common. Gearboxes can take the power from a Shaft and change the ratio of Torque to Speed without losing Power in the change. Gearboxes are necessary at all stages of RotaryCraft progression: at first to activate machines, and later to power them up. Many other tech mods' machines can be upgraded in some way to increase their speed at the cost of more power. In RotaryCraft, many machines will do that on their own if they are given higher Speeds than their minimum requirements. Generally, each time Speed is doubled, each action taken by the machine will happen 1–3 seconds faster, starting at 20–60 seconds, but eventually scaling down to 1 tick per action if enough power is given.
Similar to other mods, there are limits to power transmission. Shafts and Gearboxes have finite limits on their input and output Speeds and Torques based on the materials they are made of. If the limits are exceeded, Shafts break and Gearboxes explode. A table of material power limits is shown below.
One important difference between Shaft Power and other mods' power systems is that Shaft Power is not stored in machines. Machines that receive power use it immediately and continuously, and shafts not connected to machines will simply turn with no purpose. Shaft Power is made to be consumed, not stored. However, there are a few ways to store it in limited amounts:
- The Industrial Coil can be fed shaft power and then re-emit it later. When crafted with Bedrock Tension Coils, it can store more power but requires more Torque.
- The Coil Winder can store power in Tension Coils, which function similarly to portable batteries. Tension Coils can then be unwound in other Coil Winders or used to power certain RotaryCraft hand tools.
- The Flywheel does not expressly store power, but it can be fed power by an Engine and that it will transmit elsewhere. If the Engine is shut down the Flywheel will continue to supply power from its internal buffer.