Elgin Grade 345

It's a good idea to demagnetize movements before disassembly. Otherwise there's a chance of ending up with magnetized tools. Magnetism cause trouble for watches, even very small amounts.

This is the underside of the dial showing the three feet that hold the dial in place.

Dial foot screws go into the edge of the main plate of the movement and press against these feet, holding the dial.

Dial foot screws do not need to be torqued down by a gorilla...

This is one of the main causes of hairline dial cracks.

Here are the train wheels from the movement.

The escape wheel...

The forth wheel (seconds hand)...

The third wheel...

The center wheel (minute hand)...

The pallet fork and its bridge...

The pallet fork engages the escape wheel, as the balance moves from side to side, allowing a small amount of movement of the gear train with each cycle. The escapement slowly "escapes" the unwinding mainspring.

Here is another view of the pallet fork

Here is the balance cock, gold beveled pivot and cap jewels, and the screws that hold them in place

Here is the tool I use to remove the roller table. There are quite a few different gadgets out there for doing this. Some work better on smaller watches than this one.

The replacement staff...

The old staff is removed by cutting away the back hub.

It is cut down to almost, but not quite nothing.

The remaining bit is then easily popped off

This is the balance wheel, the old staff, and the ring of steel broken off to free it.

The new staff is riveted in place.

The hairspring is seated, and turned to the approximate position using a stake with a small tab on the edge that engage the gap in the collet. Finer adjustments can me bade to the hairspring's orientation later.

This is the completed balance assembly showing the hairspring on one side and the double roller on the other.

This is an Elgin grade 345, 12 size, 17 jewels, made about 1924.