Floor Loom Construction

Part of Textiles and Weaving

A floor loom is the machine that transforms spun yarn into woven cloth at practical speeds. Building one from wood requires intermediate carpentry skills, but the resulting tool can produce fabric for clothing, blankets, and shelter for decades.

A simple frame loom or backstrap loom suffices for narrow strips of fabric. But to produce cloth wide enough for blankets, clothing panels, and practical use, you need a floor loom — a freestanding frame with a mechanism to raise and lower groups of warp threads, allowing the weaver to pass weft thread through hundreds of threads in a single motion. This article covers building a two-shaft counterbalance loom capable of producing plain-weave fabric up to 70 cm wide.

Loom Anatomy and Terminology

Before building, understand every component:

Component	Function	Typical Dimensions
Side frames	Structural uprights	120 cm tall, 100 cm deep
Warp beam	Rear roller holding unwoven warp	80 cm wide, 8-10 cm diameter
Cloth beam	Front roller collecting woven fabric	80 cm wide, 8-10 cm diameter
Shafts (harnesses)	Frames holding heddles that lift warp threads	75 cm wide, 15 cm tall
Heddles	Individual loops on shafts, each holding one warp thread	String or wire, 25-30 cm long
Reed (beater)	Comb that spaces warp threads and beats weft into place	75 cm wide, 10 cm tall
Beater frame	Swinging frame holding the reed	80 cm wide, 60 cm tall
Treadles	Foot pedals connected to shafts	2 treadles for 2-shaft loom
Lamms	Connecting levers between treadles and shafts	Horizontal bars below shafts
Breast beam	Front crossbar at weaver’s chest height	80 cm wide
Back beam	Rear crossbar above warp beam	80 cm wide

Materials List

Wood Requirements

Use hardwood where possible — oak, maple, ash, or beech. Softwood (pine) works for the frame but wears faster at pivot points.

Part	Quantity	Dimensions	Wood Type
Side frame uprights	4	120 x 8 x 5 cm	Hardwood
Side frame horizontals	4	100 x 8 x 5 cm	Hardwood
Cross beams (breast, back)	2	80 x 8 x 5 cm	Hardwood
Warp beam	1	85 cm long, 8-10 cm dia	Hardwood
Cloth beam	1	85 cm long, 8-10 cm dia	Hardwood
Shaft bars	4	75 x 3 x 2 cm	Hardwood
Beater uprights	2	65 x 5 x 4 cm	Hardwood
Beater crossbar	1	80 x 5 x 4 cm	Hardwood
Reed holder bars	2	78 x 2 x 2 cm	Hardwood
Treadle bars	2	80 x 4 x 3 cm	Hardwood
Lamm bars	2	50 x 3 x 2 cm	Hardwood

Hardware and Supplies

• Wooden pegs or dowels (at least 30, various sizes) — or screws/bolts if available
• Strong cord or rope (10 meters) for shaft connections
• Thin, strong string (50+ meters) for heddles
• Flat strips of wood, bamboo, or metal for reed dents (teeth)
• Leather strips for bearings (beam journals)
• Wood glue or hide glue

Precision Matters

A loom demands more precision than most woodworking projects. Beams must be parallel. The warp and cloth beams must be exactly the same distance apart on both sides. Shafts must rise evenly. Misalignment of even 5 mm across the width produces uneven cloth. Take time measuring and checking square at every stage.

Step-by-Step Construction

Phase 1: Side Frames

Each side frame is a rectangle: two uprights (120 cm) and two horizontals (100 cm), joined with mortise-and-tenon joints or lap joints secured with pegs.

1. Cut mortises 5 cm from each end of the uprights
2. Cut matching tenons on the horizontals
3. Dry-fit and check for square — measure diagonals (they must be equal)
4. Glue and peg all joints
5. Build two identical side frames

Critical: Both frames must be exactly the same size. Stack them together and check alignment at every corner before the glue sets.

Phase 2: Cross Beams

Connect the two side frames with breast beam (front) and back beam (rear):

1. Mark identical positions on both side frames for beam mounting
2. Breast beam sits at approximately 70 cm height (chest level when seated)
3. Back beam sits at approximately 80 cm height (slightly above breast beam)
4. Attach with through-mortise and peg, or bolt through the side frame

Phase 3: Warp and Cloth Beams

These are the rotating cylinders that hold the warp under tension.

1. Turn or shape round beams from straight-grained logs (8-10 cm diameter, 85 cm long)
2. Cut a slot along the full length of each beam — this holds a flat stick (apron rod) where warp threads tie on
3. Shape reduced-diameter journals (bearing ends) at each end
4. Cut bearing notches in the side frames — U-shaped slots lined with leather
5. Warp beam mounts at the rear, below the back beam
6. Cloth beam mounts at the front, below the breast beam

Tension mechanism: Drill a series of holes around a wooden disk (ratchet wheel) attached to each beam end. A pivoting wooden pawl drops into these holes to prevent the beam from turning backward. You need a ratchet on at least the warp beam; the cloth beam can use friction or a simpler clamp.

Ratchet Alternative

If you cannot make a ratchet wheel, use a simple rope-and-peg brake: wrap rope around the beam end 2-3 times, tie to a lever. Pulling the lever tightens the rope friction; releasing allows the beam to advance. Cruder but functional.

Phase 4: Shaft (Harness) Construction

For a two-shaft loom, build two identical rectangular frames:

1. Cut four bars: two top bars and two bottom bars, each 75 cm long
2. Join into rectangles approximately 75 cm wide by 15 cm tall
3. Use lightweight wood — these frames must move up and down freely
4. The heddles hang between the top and bottom bars of each shaft

Making String Heddles

Heddles are the loops through which individual warp threads pass. For a 70 cm weaving width with warp threads at 5 per centimeter, you need approximately 350 heddles (175 per shaft for plain weave).

1. Make a heddle jig: a board with two nails/pegs 25-30 cm apart, and a center peg
2. Wrap strong, smooth string around the pegs in a figure-eight pattern, crossing at the center peg
3. Each figure-eight creates one heddle — the center crossing forms the “eye” through which the warp thread passes
4. Tie a knot at each end to form loops
5. Slide heddles onto the shaft bars — top loop on top bar, bottom loop on bottom bar

Heddle Length Consistency

Every heddle must be exactly the same length. Uneven heddles mean some warp threads are tighter than others, causing uneven fabric, broken threads, and frustration. Use the jig for every single heddle — do not estimate or shortcut.

Phase 5: Reed and Beater

The reed spaces the warp threads evenly and beats each weft row tight.

Building a reed:

1. Cut two long strips of hardwood (78 cm) — these are the top and bottom rail of the reed
2. Cut a groove along the inner face of each strip
3. Prepare dents (teeth): thin strips of bamboo, wire, or hardwood, all identical width
4. Space dents evenly in the grooves — spacing determines thread density (sett)

Fabric Type	Dents per cm	Thread Spacing
Coarse blanket	3-4	2.5-3.3 mm
Utility cloth	5-6	1.7-2.0 mm
Fine fabric	8-10	1.0-1.25 mm

5. Glue dents into grooves or bind with thread wrapping

Building the beater frame:

1. Two upright posts (65 cm) mounted to pivot on the loom frame at the breast beam level
2. A crossbar at the top connecting the two uprights
3. The reed sits in a slot or groove at the bottom of the beater
4. The beater swings forward toward the weaver to beat the weft, then swings back

Phase 6: Treadles and Lamms

The treadle mechanism allows foot-operated shaft control:

1. Mount two treadle bars horizontally below the loom, pivoting at the rear
2. Each treadle is connected by cord through a lamm to one shaft
3. When you press a treadle with your foot, it pulls one shaft down (in a counterbalance system, this raises the other shaft)
4. Lamms are intermediate levers that allow proper mechanical advantage

Counterbalance system: Suspend both shafts from a pivot (roller or pulley) at the top of the loom frame. When one shaft goes down, the other goes up — they balance each other. Connect each treadle to one shaft via cord and lamm. Pressing treadle 1 lowers shaft 1 and raises shaft 2, creating the shed (opening) for the weft to pass through.

Test the Action Before Warping

Operate the treadles without any warp on the loom. Both shafts should rise and fall smoothly with equal travel. If one side sticks or travels less than the other, adjust cord lengths and pivot points now — fixing these problems with a warp under tension is far harder.

Threading the Loom (Warping)

With the loom built, warping is the setup process before weaving:

1. Calculate warp length: Desired fabric length + 50 cm waste (loom allowance)
2. Wind the warp: Use a warping board or pegs to measure uniform-length threads
3. Beam the warp: Spread threads across the warp beam, wind on evenly with paper or sticks between layers to maintain tension
4. Thread heddles: Pass each warp thread through one heddle eye, alternating shaft 1, shaft 2, shaft 1, shaft 2 for plain weave
5. Sley the reed: Pass each thread through a dent in the reed
6. Tie on: Tie warp thread groups to the cloth beam apron rod
7. Tension: Advance the warp beam ratchet until all threads are equally taut

Threading Order for Plain Weave

Plain weave (the simplest and most useful pattern) alternates: thread 1 through shaft 1, thread 2 through shaft 2, thread 3 through shaft 1, and so on across the full width.

When you press treadle 1, all shaft-1 threads rise, all shaft-2 threads stay down — creating a clear opening (shed) for the weft to pass through. Alternate treadles with each weft pass.

Maintaining Your Loom

Issue	Cause	Solution
Beams don’t turn smoothly	Dry bearings	Lubricate journals with tallow or beeswax
Shafts don’t rise evenly	Unequal cord lengths	Measure and adjust connecting cords
Reed dents breaking	Brittle material	Replace with green bamboo splits, soak before bending
Treadle stiff	Pivot point friction	Widen pivot holes slightly, lubricate
Cloth wider at one edge	Uneven warp tension	Re-tension, check beam alignment

Design Variations

This design describes a two-shaft counterbalance loom for plain weave. With modifications:

• Four shafts allow twill patterns (diagonal weave, herringbone) — add two more shafts, four treadles, and more complex tie-up
• Jack loom design lifts individual shafts independently rather than using counterbalance — more versatile but more complex
• Wider looms (100+ cm) need sturdier frames and a second person to throw the shuttle — consider a fly shuttle mechanism

Floor Loom Construction Summary

A two-shaft counterbalance floor loom requires two matching side frames connected by cross beams, rotating warp and cloth beams with ratchet tension, two heddle-bearing shafts suspended from a counterbalance pivot, a swinging reed/beater for spacing and packing weft, and treadles connected via lamms to the shafts. Critical dimensions: 70 cm weaving width, 120 cm frame height. Build with hardwood at all wear points, maintain parallel alignment throughout. String heddles must be uniform length (use a jig). Start with plain weave (alternating shaft threading) — a single loom operated by one person can produce enough cloth for a household. The most common mistake is insufficient attention to squareness and parallel alignment during construction.