Editing Loom (section)

===Motions===
[[File:Belarus weaving.jpg|thumb|Passing the [[Shuttle (weaving)|shuttle]] through the shed]]
A loom has to perform three '''principal motions''': shedding, picking, and battening. 

*'''Shedding'''. Shedding is pulling part of the [[warp (weaving)|warp]] threads aside to form a [[shed (weaving)|shed]] (the space between the raised and unraised warp yarns). The shed is the space through which the filling yarn, carried by the shuttle, can be inserted, forming the weft. 
**Sheds may be simple: for instance, lifting all the odd threads and all the even threads alternately produces a [[tabby weave]] (the two sheds are called the shed and countershed). More intricate shedding sequences can produce more complex weaves, such as [[twill weave|twill]].
*'''Picking'''. A single crossing of the weft thread from one side of the loom to the other, through the shed, is known as a pick. Picking is passing the weft through the shed. A new shed is then formed before a new pick is inserted. 
**Conventional shuttle looms can operate at speeds of about 150 to 160 picks per minute.<ref name="Collier 1970 104">{{harvnb|Collier|1970|p=104}}.</ref>
*'''Battening'''. After the pick, the new pass of weft thread has to be tamped up against the fell, to avoid making a fabric with large, irregular gaps between the weft threads. This compression of the weft threads is called battening.

There are also usually two '''secondary motions''', because the newly constructed fabric must be wound onto cloth beam. This process is called taking up. At the same time, the warp yarns must be let off or released from the warp beam, unwinding from it. To become fully automatic, a loom needs a '''tertiary motion''', the filling stop motion. This will brake the loom if the weft thread breaks.<ref name="Collier 1970 104"/> An automatic loom requires 0.125&nbsp;hp to 0.5&nbsp;hp to operate (100W to 400W).