Sewing Machine Bobbin Wound Unevenly: Winder Friction Disc Adjustment

You hit the bobbin winder, the wheel spins, and the thread piles up on one side of the bobbin while the other side stays nearly empty. The bobbin goes into your sewing machine and the stitches are loose on one side and tight on the other. This is a classic winder friction disc problem, and it is almost always an easy fix.

What Causes Uneven Winding

The bobbin winder has a small friction disc or friction pad on the winder arm. This component creates resistance against the bobbin, which makes the thread spread evenly across the bobbin as it spins. When the friction disc wears down, gets glazed over with old thread finish, or loses its spring tension, the bobbin no longer gets enough friction to distribute the thread evenly.

The result: the thread stays in one spot on the bobbin, building up into a lopsided mass.

Locating the Friction Disc

On most sewing machines, the friction disc is on the winder arm itself — the piece that presses down against the top of the bobbin. It may look like:

A small rubber or felt disc pressed into the arm
A setscrew with a friction washer underneath
A metal disc with a spring-loaded center pin

On some Brother and Janome machines, the friction is provided by a simple metal tab that contacts the bobbin flange. On older Singers, there is a rubber tire on the winder wheel that contacts the handwheel — if that tire gets hard or worn, it cannot spin the bobbin fast enough to wind evenly.

The Adjustment Procedure

Remove the bobbin and any thread from the winder.
Locate the friction disc or setscrew. It is usually on the top or side of the winder arm where it contacts the bobbin.
Turn the setscrew clockwise (tighten) by 1/8 turn. Use a small flathead screwdriver or a hex wrench depending on the screw type.
Test wind a bobbin. Watch the thread build. It should fill the bobbin evenly from one side to the other.
Repeat if needed. If the thread still piles up on one side, tighten another 1/8 turn. If the thread now winds too tight and breaks or the bobbin is hard to pull off, back the screw off by 1/8 turn.

If There Is No Setscrew

Some machines have a friction pad that is not adjustable — it is simply a rubber or felt disc glued into place. If this disc is worn flat or missing, you need to replace it. Friction disc replacement kits are available for most common machines and cost about $5 to $10.

To check the disc, press your fingernail into it. It should have some give. If it is hard as plastic, it needs replacing.

Other Possible Causes

Bobbin winder tire is glazed. On machines where the winder runs off a rubber tire against the handwheel, the tire can harden or get a shiny glaze. Sand the tire lightly with fine-grit sandpaper (220 grit) to restore grip.

Incorrect bobbin type. Using the wrong bobbin (metal vs. plastic, class 15 vs. class 66) can cause uneven winding even with perfect friction. The bobbin must match your machine’s specification.

Thread tension on the winder path. The thread should run through the tension disc on the top of the machine before going to the bobbin winder. If you skip this step, there is no tension on the thread and it wraps loosely onto one side.

When to Call It

If you have tightened the setscrew all the way and the bobbin still winds unevenly, the winder mechanism may be bent or the bobbin spindle may be worn. At that point, replacing the winder assembly is usually cheaper than trying to straighten a bent part.

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