Weaving Loom Types
Woven fabric formation machinery
The earliest art of hand weaving along with hand spinning remains a popular craft. There are different types of weaving looms and these include handloom, frame loom, and backstrap loom. A loom is a mechanism or tool used for weaving yarn and thread into textiles. Looms vary in a wide assortment of sizes. They come in huge freestanding handlooms, tiny hand-held frames, with vast automatic mechanical tools. A loom can as well pertain to an electric line construction like that of a wiring loom.
Types of Looms
The following is a description of the three main types of looms: Counterbalance, Jack, and Countermarch, plus a brief description of Table looms and Drawlooms. If you are not familiar with these three basic types of looms, look at the diagrams in Peggy Osterkamp’s book Warping Your Loom.
This type is found in nearly every country and is the traditional type of loom used in this country. Pulleys, horses or roller dowels are used to hang shafts so that when at rest the warp threads are neither pulled up nor down. When a shed is made, some shafts go up and the rest go down. All of the shafts are responding to the weaver’s foot, giving smooth, quick and quiet treadling which helps the weaver to develop a rhythm while weaving.
The Counterbalance Shed
Counterbalance looms allow one to open a small shed or a large shed by giving a light touch or a stronger touch on the treadles. Small sheds give much nicer selvages and can help to prevent draw-in at the selvages. A counterbalance loom can do this because you can weave on a tighter tension and the tension on the warp threads is the same on the top and bottom of the shed at all times. The pressure on treadles regulates the size of the shed. Another advantage is that all of the shafts are moved by each treadle. There are no shafts left to keep their place only by their weight. A clear shed can be made even on closely sett or sticky warps. Also, a large clear shed can be made even on a very tight tension by pushing harder on the treadles. This is one of the reasons that rug looms are a counterbalance. The wefts can also be beaten in more securely because the warp travels straight from the breast beam to the back beam.
Weaving Unbalanced Sheds
When weaving 3 shafts against 1, on a loom which is more than 3′ deep, the shed will be very close to normal. On a small loom, the one shaft that moves opposite the three will have a tighter tension, so if you change the height of the shafts, the tension will even out. All counterbalance looms have a way to adjust the height of the shafts. If the loom is a deeper loom there is no problem with the shed. Counterbalance looms commonly have from 2 to 10 shafts, but are mostly 4. If you want 3, 5 or more shafts, you need to tie them up differently. This is done after the warp is tensioned, and you will need to use more pulleys or horses. When weaving a very narrow web on a counterbalance loom, you should wind and beam a few threads to have on both sides of the loom. Or you can attach elastic bands from the tops of the shafts to the top of the loom to keep the shafts level.
This type of loom is popular mainly in the US where it was created in the early part of the 20th century for handloom weaving. It is the type of loom used for table looms and small folding looms. Sometimes jack looms are chosen because they are readily available or are less expensive since they are smaller. Four shaft jack looms are also easy for beginners to use unless they have problems getting a good shed.
How the jack loom works
The shafts work independently, moved by jacks which can be placed above the shafts on the castle or below the shafts. The later type eliminates the need for the castle frame above the loom and is the reason so many small looms are jack type.
The shafts work by being placed a few inches below the usual path of threads going straight from the breast beam to the back beam. This lower position is maintained by having the shafts heavy enough for their weight to resist the tension on the warp threads. Weaving with a slightly looser tension is needed to keep the shafts down, especially on a wide warp.
Disadvantages of the jack system
The reliance on gravity to hold heavier shafts down gives some disadvantages which are most notable on wider or more difficult warps. The looser tension required can give you skipped threads, warps which will not separate properly when making a shed, poor selvages and the inability to weave a tight weave. Rugs cannot be easily woven on a jack loom unless the shafts are very heavy. The looser tension and lower position of the shafts make it very difficult to weave a tight weave. These problems may not be very noticeable on a 4 shaft loom when weaving lightweight fabric less than the full width.
Jack loom warp thread wear
One problem is the extra wear jack looms put on warp threads causing them to weaken and perhaps break. The reasons for this is that the shafts are holding the threads down at maximum tension, even when the loom is at rest. And when a shaft is raised, the warp loosens until it arrives at its highest position. This causes a snapping effect which can weaken threads. The looser tension of a jack loom can also cause more draw in at the selvages. The heddles are not the only thing that causes wear. Excessive draw-in of loose selvages can also cause broken warp threads. And the reed causes friction on the warp due to the raised position of the reed. Instead of having the warp threads in the center of the reed where they can move freely, they rest on the bottom of the reed. The beater is raised to give an even bottom shed and make the threads sit on the shuttle race.
Jack looms need shuttle races
Another problem is that the weaver’s rhythm is more difficult to attain. One reason is that the looser tension requires that a shuttle race be put onto the beater and it can get in the way of the hand when throwing or be catching the shuttle.
Shafts do not always fall properly, shafts are heavy and sometimes sheds do not clear
Weaving rhythm is sometimes interrupted because the falling of the shafts is not tied to the treadling and will often be slow or uneven. When they do not fall, their threads are sitting too high in the shed. Sometimes it takes an extra step on the treadle to make the falling shafts fall completely down before the shuttle can be thrown. Heavier shafts prevent this, but the heavier shafts, being more difficult to raise, can also affect a weaver’s rhythm and comfort in weaving. Sticky threads cause sheds to be more difficult. They cannot be easily cleared on a jack loom, as treadling harder will not help. Sheds which will not clear also interrupt the weaving.
Another problem is the unequal tension on the top and bottom of the shed. When a shed is made the upper threads become tighter than the threads remaining on the bottom of the shed, especially on small looms. This makes weft-faced weaving more difficult as every other thread is slightly loose. To increase the tension on the bottom of the shed you need to increase the weight of the shafts.
Lastly, I must mention the noise that results from the shafts falling onto the jacks or the jack box. Most jack looms have metal heddles to add weight to the shafts and when the shafts fall to the jacks there is a disconcerting metallic rattle.
When using a jack loom I would recommend avoiding weaving full width when you are also weaving warp-faced weaves, close setts, fuzzy or sticky warps or unbalanced weaves on more than four shafts. With these weaves, it may be difficult to open the sheds, especially on a wide warp. Treadle springs can be added to help clarify difficult sheds.
This loom of Scandinavian and European design is becoming more available and more popular in the US. It gives the advantages of a counterbalance loom: quiet, smooth and light treadling on a tight tension.
How does the countermarch loom work?
An extra set of lamms, usually at least a foot longer than the other lamms, allows the shafts to be tied up more completely. You can imagine this as a tie-up of a jack loom with the addition of a way to also tie up the falling shafts to the treadles. This makes all the shafts respond to the weaver’s command when treadling.
How does this extra set of lamms affect the loom?
This extra set of lamms often makes the loom taller and they are the reason that there is twice the number of ties to the treadles. It is like tying up the ties for a jack loom and then tying up all the empty spaces you left. As with many counterbalances looms, you must put a warp onto the loom before tying up the lamms and treadles, as the shafts need the warp threads in order to work. At first, it seems that it is more work to tie up a countermarch loom, but the first part is the same as other types of looms, and tying up all the leftover places does not add a lot of time. And the savings in ease of weaving and ease of treadling more than a makeup for it. You can add any number of treadles and shafts without getting a new loom frame, so it is a good choice for those who want more than 4 shafts.
Horizontal and vertical countermarch
There is a castle on a countermarch loom as the countermarch jacks are at the top of the loom. Horizontal countermarch looms have two jacks for each shaft and they sit horizontally. Vertical countermarch looms have one jack for each shaft and they sit vertically. Both types of countermarch are available. There is little difference in the weaving when using the two types. The second set of lamms is longer on the vertical countermarch and the cords for typing them are on the outside of the loom, rather than in the center of the loom. The horizontal countermarch is often less expensive and more common.
Since countermarch looms have castles, there is usually a hanging beater attached to the castle. This gives better control of the beat, a better view of the weaving as you beat, and allows you to have a heavier beater. Countermarch looms are often deeper than jack looms. This gives a more even tension, more even beat and easier treadling, usually because they are made in Scandinavia where looms are made deeper.
These smaller, less expensive, portable looms are usually jack looms. Sometimes they have springs under the shafts to hold them down as the small shafts do not have enough weight of their own to stay down. Table looms are used for learning as they are portable enough to put into a car or even on a plane to take to a workshop.
The disadvantages of a table loom for weaving are first that the weaving progresses more slowly because there are no treadles. Secondly, because you use your hands to move levers to change sheds, you must always interrupt the weaving and usually put the shuttle down. Thirdly, the shorter distance front to back gives a less even beat and some difficulty producing even selvages and an even width.
This type of loom is a two harness loom. The first harness has 4, 5 or 6 shafts and they weave the ground weave. You only need 4, 5 or 6 treadles for weaving these shafts. The second harness is either a single unit draw, giving images with no repeat, or a shaft draw which gives repeat patterns.
The second Harness
The second harness is placed behind the first harness. The single unit draw has groups of warp threads attached to a cord and these cords are pulled to make the pattern. The shaft drawloom is set up with pull handles which are attached to 10 to 100 shafts. They are threaded to weave a fixed size of a repeat but can make an infinite number of patterns. The single unit drawloom gives the most flexibility of design and is easier to thread, but takes more time to draw the cords while weaving. There is combination looms with both the single unit and the shaft systems in one loom.
Long eyed heddles and pattern heddles
The heddles on the shafts of the first harness have long eyes of about 2 ½”. These shafts produce the ground weave. Traditionally this is twill, broken twill or satin since this is not the major design feature. If you have 4 or 6 shafts you usually use a counterbalance tie up. If you have 5 shafts it is best to use a countermarch. A jack loom cannot be used as there are always some shafts which remain in a neutral position, one shaft which rises and one which sinks. Elastic bands or counterweights are used to hold the shafts which remain in the neutral position.
The second harness has very long heddles with normal eyes. When the weaver pulls the threads up by a handle or a cord, the threads rise to the top of the long eyes of the other heddles in the ground shafts. This allows a shed to be produced even in the group of threads pulled up. The back harness threads are placed in groups of 4, 5 or 6 threads, corresponding to the number of shafts in the first harness. Designs are planned on graph paper. Each square represents a group of warp threads (4, 5 or 6), and an equal number of weft shots treadled in order.
These groups of warp threads are pulled up according to the graph design and then the wefts are woven for that row.
Added loom depth
Since the second harness is in the center of the loom, the loom needs to be about 2 feet deeper than usual. If you have a shaft drawloom the more shafts you use, the deeper the loom needs to be, up to 3 or 4 feet deeper. This is especially true for nonstretchy warps.
One can use a drawloom to expand the number of blocks in a pattern weave such as summer and winter or crackle. The shaft type drawloom is used in this case.