### Section: PageInfo
title=About Rotational Energy
icon=polyfactory:large_steel_gear
category=polyfactory:rotation
### EndSection: PageInfo

<yellow>Rotational Energy</> is the main source of power for most machines added by PolyFactory.
This means that understanding how it works is important if you don't want to be confused why it doesn't work.
<nl2>
The rotational energy is composed of two variables:
- <yellow>Speed</> - controls how fast elements are rotating or machines are working.
- <yellow>Capacity</> - sometimes referred as *stress capacity* or *torque*, defines how much energy
is available to do things.
<nl>
Different machines might use these variables differently. Some only care about speed, some require some static capacity,
while having flexible speed and some change the capacity requirement depending on speed.
<nl2>
This also applies when generating the rotational energy, as different sources will have different relations to generated
speed and capacity. In case of multiple sources, the speed will be averaged out if they don't generate equal amount
of it. In case of capacity it will be added up instead.
<nl2>
To generate it, you can use:
- Hand Crank (<u><blue><polydex 'polyfactory:hand_crank'>recipe</*>) - simple, but requires player input,
- <u><blue><pagelink 'polyfactory:rotation/20_windmill'>Windmill</*> - passive source of energy, depending on position and external factors,
- Steam Engine (<u><blue><polydex 'polyfactory:steam_engine'>recipe</*>) - burns fuel, but works everywhere and generates highest speed and energy/
<nl2>
Naturally then you need to connect it to the machine somehow.
To do this at distance, you can use Axles, Steel Gears, Gearboxes and other blocks (see rest of the Rotational Energy category and recipe list).
<nl2>
All machines that take the rotational energy usually only allow to connect it from one or two points, for example
with <item 'polyfactory:grinder'> being connectable from top and bottom and any 2 block tall machine being connectable on upper blocks left and right sides.
<nl2>
In case where you ran out of the stress capacity, the entire network will lock up and prevent all connected machines from working.
For this reason it might be useful to separate them into multiple disconnected networks.