Balance Staffs



Balance Staffs
Balance Jewels



Correct replacement of the balance staff in a mechanical watch is of the utmost importance.  If the staff is not properly installed, a good watch will become a poor timekeeper.  When the balance staff is correctly installed, the balance wheel will run true and level with relationship to the axis of the pivots on the balance staff.

If the balance staff does not run true and level, the watches ability to keep good time in all positions will be affected.  The photographs in the following gallery shows the replacement of a staff in a Elgin convertible pocket watch.  There are two kinds of staffs.  There are friction fit staffs and riveted types of balance staffs.  This particular watch uses the rivet type of staff that is staked onto the balance wheel.

Be Sure To Click On Any Image For A Large Version


Balance Assembly

These are the component parts of the balance. The balance wheel with staff, hairspring, roller table and balance bridge.

Broken Staff.

This shows the broken pivot of the staff. It is at the bottom.

Elgin Convertible Movement.

This is the movement that contained the damaged balance staff.

Dial Side.

This is the dial side of this rather rare movement.

Balance Wheel In Lathe.

The balance wheel is being setup for the removal of the damaged balance staff.

Cutting Out the Staff.

Here the staff is being cut our of the balance wheel. This is done with a graver.

Removing The Staff.

The staff rivet has been cut away allowing the staff to be driven out of the balance wheel.

The New Staff.

The new staff is now ready to receive the balance wheel.

Staking The Staff.

Here the balance staff is being staked or riveted onto the balance wheel.

Test the New Staff.

Here the new staff without the roller table and hairspring is checked for proper fit in the movement.

Roller Table.

Here the roller table is placed onto the staff.

Installing the Roller Table.

A special stake with a milled slot is used to install the roller table. This slot prevents the roller jewel from being damaged.

Roller Table Set.

The roller table is now staked onto the balance staff.

Another View.

Here is another view of the roller table in position.

Installing the Hairspring.

Here the hairpring is pressed onto the balance wheel. Using the staking set prevents damage to the balance wheel and hairspring.

Finished Balance Wheel.

This shows the finished balance wheel. It has been checked to make sure that it is running true and level.

Another View.

This shows another view of the balance wheel. If it is not true and level with relationship to the staff, the watch will not be a good timekeeper.

Letting Down the Mainspring.

The watch is now ready for cleaning, oiling and regulation. All power from the mainspring is let down so the watch can be taken apart for cleaning.

Elgin Convertible.

These rare watches can be used either as a hunter cased watch or as an open faced watch. Placement of the winding mechanism determines which one is used.

Winding Gears.

This shows the winding gears of the movement.

Finished Movement.

Here the movement is ready to be placed back into its 14kt. gold hunting case.

The Waltham Friction Fit Balance Staff.

One of the most innovative inventions of the pocket watch industry was the design of the friction fit balance staff.  These staffs were used not only by Waltham, but other companies such as Hamilton and Howard also used them.  The friction fit staff made it possible to install a new staff without the need to cut out the old staff using the watchmakers lathe.  The only tools required was the staking set.  Click on the following picture to see details of the Waltham friction fit balance staff.

Friction fit balance staffs almost eliminated damage to the delicate balance wheel that could be caused by cutting the old staff out using the lathe or damage cause by distorting to balance arms when staking in a new rivet style balance staff.  Many watchmakers that worked in the days leading up to the friction fit balance staff hailed it as one of the greatest inventions of the watchmaking industry.



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