Editing Loom (section)

==Components and actions==
{{see also|Weaving|Textile manufacturing terminology}}

===Basic structure===
<imagemap align=left>
File:Simple_treadle_floorloom,_line_drawing.png|thumb|upright=1.5|left|A simple treadle floor loom. Mouse over components for pop-up links. The warp runs horizontally. On the left the warp beam, held from turning by with a weighted trough to keep the warp taut; on the right, the cloth beam (also called a ''breast beam'' on this type of loom), with a [[Ratchet (device)|pawl and ratchet]] to allow the weaver to roll up the fell. In the center, devices for performing the motions of weaving.

poly 735 1063 1335 731 1488 825 1016 1148 [[Lease rods]]
poly 1360 808 1904 553 1921 1152 1399 1437 [[Heddle|Heddles and heddle frames or harness]]
poly 2036 510 1998 1386 2678 812 2614 315 [[Beater (weaving)|Batten bar or beater bar]]
poly 2155 1063 2538 799 2542 888 2164 1161 [[Reed (weaving)|Reed]]
poly 2648 816 2559 922 2627 961 2721 876 [[Shuttle (weaving)|Shuttle]]
poly 1611 1590 1462 1836 2780 2023 2993 1768 [[Treadle]]s
poly 2729 829 2470 1058 2491 1271 2835 969 2831 820 [[Breast beam]]
poly 327 990 336 1186 999 897 1024 799 973 723 [[Warp beam]]

desc bottom-left
</imagemap>

[[File:loomwork.jpg|thumb|Weaving a tapestry on a [[#Tapestry looms|vertical loom]] in [[Konya]], Turkey]]
[[File:Ankara 4P5C4752 (27616736687).jpg|thumb|upright|A Turkish carpet loom showing warp threads wrapped around the warp beam, above, and the fell being wrapped onto the cloth beam below.]]
[[File:Tropenmuseum Royal Tropical Institute Objectnumber 403-150 Toestel voor het vervaardigen van kral.jpg|thumb|A simple handheld frame loom]]

Weaving is done on two sets of threads or yarns, which cross one another. The [[Warp (weaving)|warp]] threads are the ones stretched on the loom (from the [[Proto-Indo-European]] *''[[:wiktionary:warp|werp]]'', "to bend"<ref>{{cite web|url=http://www.etymonline.com/index.php?allowed_in_frame=0&search=warp|title=warp - Search Online Etymology Dictionary|website=www.etymonline.com}}</ref>). Each thread of the [[weft]] (i.e. "that which is woven") is inserted so that it passes over and under the warp threads.

The ends of the warp threads are usually fastened to beams. One end is fastened to one beam, the other end to a second beam, so that the warp threads all lie parallel and are all the same length. The beams are held apart to keep the warp threads taut. 

The textile is woven starting at one end of the warp threads, and progressing towards the other end. The beam on the finished-fabric end is called the ''cloth beam''. The other beam is called the ''warp beam''. 

Beams may be used as rollers to allow the weaver to weave a piece of cloth longer than the loom. As the cloth is woven, the warp threads are gradually unrolled from the warp beam, and the woven portion of the cloth is rolled up onto the cloth beam (which is also called the ''takeup roll''). The portion of the fabric that has already been formed but not yet rolled up on the takeup roll is called the ''fell''. 

Not all looms have two beams. For instance, warp-weighted looms have only one beam; the warp yarns hang from this beam. The bottom ends of the warp yarns are tied to dangling loom weights.

<gallery mode="packed" heights="200">
File:Weaving demonstrated on a historic loom in Leiden.webm|thumbtime=12|Weaving demonstration on an 1830 handloom in the [[Museum Het Leids Wevershuis|weaving museum]] in [[Leiden]]
</gallery>

{{clear}}

===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).

===Components===
A loom, then, usually needs two beams, and some way to hold them apart. It generally has additional components to make shedding, picking, and battening faster and easier. There are also often components to help take up the fell.

The nature of the loom frame and the shedding, picking, and battening devices vary. Looms come in a wide variety of types, many of them specialized for specific types of weaving. They are also specialized for the lifestyle of the weaver. For instance, nomadic weavers tend to use lighter, more portable looms, while weavers living in cramped city dwellings are more likely to use a tall upright loom, or a loom that folds into a narrow space when not in use.