Intro to Rotary2
crossroads:gear_base
<thing>Rotary/$ is one of the basic energy systems in Crossroads, and usually the first or second one you'll use (alongside <thing><link:intro/heat>Heat/$) Rotary is the transfer of mechanical energy using <item>gears/$ and <item>axles/$.
Rotary can seem complicated at first when reading about it, but is actually pretty simple in practice.
Every gear, axle, or other spinning device has a few basic values.
The <thing>Moment of Inertia/$ is written as 'I', usually in tooltips. The I value can be thought of as the 'weight' of the gear- things with higher I values are heavier and are harder to spin quickly.
The <thing>Speed/$, usually written 'ω' and measured in 'rad/s' in tooltips, is how fast something is spinning. A normal speed might be 2-4rad/s, while 10rad/s is very fast. A negative speed means the gear is spinning clockwise (counter-clockwise is positive).
The <thing>Energy/$, usually written 'E' and measured in 'J', is the total energy in a spinning object. As you'ld expect, the faster somethings' speed, the more energy it has, and the higher the I, the more energy. There is actually a formula (E=Iω²/2), but it isn't useful or worth remembering.
The <thing>Power/$, measured in 'J/s', is the rate of change of the energy of a gear. No machines look at the power value at all- it only exists to help show the player the change in energy.
Gears will also have a small amount of <thing>energy loss/$ proportional to the <thing>speed/$. This is a slow decrease in <thing>energy/$ over time unless power is supplied.

Usually, a machine will consume a certain amount of <thing>energy/$ per operation, but have a minimum <thing>speed/$ to work. Most machines will work faster at higher <thing>speeds/$.
<item><link:rotary/gear_base>Gears and axles/$ can be connected together to transfer energy. Placing a <item><link:rotary/gear_base>small gear/$ next to a <item><link:rotary/gear_large>large gear/$ will cause the larger gear to spin slower than the small one- as you'ld expect.

All networks of gears/axles/whatever <em>MUST HAVE/$ a <item><link:rotary/axis>Master Axis/$ connected somewhere in the network- otherwise nothing will work!