Archive for February 24th, 2015

Kenmore 158: Bobbin Winder Repair

For reasons which are, trust me on this, not relevant here, we now have a third Kenmore 158 sewing machine: a freebie that sat under a roof leak in an unused room some years ago and wasn’t cleaned before being stored. Even though not much water got inside the covers, the bobbin winder shaft froze solid.

Two black screws hold it to the cover and provide a slight adjustment of the tire-to-handwheel distance:

Bobbin Winder - old tire

Bobbin Winder – old tire

Prior to this adventure, I soaked the shaft in penetrating oil for a week or two, but to no avail.

I didn’t take any before-the-repair photos, but it looked like this afterward, with the new tire installed…

From the top right (looking over the handwheel):

Bobbin Winder - assembled - top right

Bobbin Winder – assembled – top right

Notice the small rectangular hole just below the larger section of the shaft in the protruding part of the pot metal housing. That’s supposed to be an oil hole, but it’s also a fine water inlet.

From the top left:

Bobbin Winder - assembled - top left

Bobbin Winder – assembled – top left

The two obvious screws remove the obvious parts, but beware the compression spring:

Bobbin Winder - fill sense lever

Bobbin Winder – fill sense lever

And the torsion spring:

Bobbin Winder - drive latch

Bobbin Winder – drive latch

Some experimentation with a strap wrench rotated the wheel on the (still firmly frozen) shaft, which suggested the joint was a press fit without a setscrew, splines, or adhesive.

Grabbing the shaft lightly in a machinist’s vise, resting it atop the bench vise, and giving it a few shots with a drift punch drove it downward through the housing:

Bobbin Winder - driving out spindle

Bobbin Winder – driving out spindle

More gentle beating produced this heartrending scene:

Bobbin Winder - corroded shaft

Bobbin Winder – corroded shaft

Water just isn’t any good at all for unlubricated steel in a pot-metal bushing…

Anyhow, the shaft & housing cleaned up well, although they look a tad grody, and everything went back together in the reverse order.

I added a drop of light oil through the lube port, chucked the shaft in the drill press, spun it for a minute at low speed to wear off a slight binding, and it’s all good again.