Powered Bellows

Blows air into whatever it's touching. Air makes a fire burn hotter. It's the only way past a fuel's normal temperature, and the only way to reach steel.

Crafting

L P L
L S L

L is Leather, P is any Planks and S is a Shaft.

Setting it up

The bellows is driven by strokes from a Crank Linkage, the same way a hammer is. Put it in front of the linkage, and touching what you want to blow into:

• a Firebox (under a crucible or boiler),
• a self-fired furnace,
• a Valve, to cut the air on and off,
• a Pressure Vessel.

It blows into everything it touches, sharing each stroke between them.

Throw: long is better here

On the bellows, the linkage's long throw moves 30 mB of air per stroke and the short throw only 10 mB. That's the opposite of the hammer, where short is the strong one.

A fully blown fire burns 4 mB of air a tick. A long throw keeps up with that at about 21 RPM. A short throw would need 64 RPM.

Gearing the linkage down doesn't squeeze any more air out of a stroke. It only changes how often the bellows strokes. Faster strokes mean more air per second.

What air does

A fire needs a steady supply of air to stay hot. Keep the bellows pumping and the fire climbs to as much as 1.5× what the fuel does on its own (charcoal: 1220 Tu to 1830 Tu). Stop, and the fire falls back to normal within a second or so.

Air only makes the fire hotter. The fuel doesn't burn any faster.

Controlling it

The bellows has no on/off switch. It runs whenever its shaft turns. To control it, put a Clutch on its shaft and switch that, by hand or with a Bimetallic Strip, Timer or Controller. Or put a Valve between it and the fire.

It's a load of 40 Su on the shaft, half a hammer.

Remember that the bellows can only add heat. To take heat away, use a Damper.