Dorrin K Mace, Horologost

Dorrin K Mace, Horologost
The Clock Man in a pensive moment

Sunday, July 8, 2012

What makes a superior clock?

Many customers will wonder about the gearing in clocks and wonder out loud what makes one clock better than another. 
Simply put, it is the engineering that makes one clock superior to another.   When I say engineering I am talking about the metal for the plates, the gearing, the chiming mechanism and the case work.  If any of these are done haphazardly, a less that desirable clock time piece is the result.
Let us begin by looking at the materials used for the front and back plate of a clock movement.
The plates are the material (either metal or wood) that are used to hold the gearing and chiming mechanism in place for a clock movement.
Through the years many materials were utilized for these plates.  I have seen wood, iron, steel, bronze, brass, chrome plated steel, and even hard thermo plastics.  The plastics are usually on electric movements.
Each material has its good and bad properties; I provide a few examples below
WOOD
Pros:      Inexpensive
                Easy to work
                Can be bushed and re-bushed easily
Cons:     Not stable (warps)
              Cannot be oiled , let me explain.  Many time a less than consummate repairman or clock owner  will  want to lubricate their own timepiece, that is fine if they knew what to do.  A wooden movement can only have a small drop of oil placed on the pivots IF THE GEARING IS NOT WOOD.  I have seen many movement come into the shop frozen in time from over zealous oiling that swelled the wood and caused the movement to cease to function.  I have dried many out in an old heat cabinet I have and shaved them  down to work.  This was done only after discussing this with the owner and letting them know this is a short term work around, but the movement will need all gearing recut once the oil dissipates.

BRONZE
Pros:      Easy to work
              Long wearing
              Can be punched to nearly any desired requirement
Cons:     Creates oxides that destroy the pivots
              Can become so hard it is difficult to work
              Brittle

STEEL & CHROME PLATED STEEL
Pros :     Cheap
                Plentiful
                Fast to work
                Strong
Cons:     Corrodes (rusts)
                Pits
                Cannot be repaired easily
               
IRON
Pros:      None Currently
Cons:     Corrodes
                Brittle
                Cannot be easily repaired

BRASS
Pros:      Inexpensive
                Easy to work
                Easy to bush
                Easy to repair
Cons:     Not a strong material

PLASTICS
Pros:      Cheap
                Easy to manufacture
                Versitile
Cons:     Not long wearing
                Difficult to repair


Gearing, these can be of several forms:
hobbed (cut), pressed from sintered metals (powdered), Punched, assembled (such as a pinion gear)

The cut gears can be made to the closest tolerance and are the most precise.

The chiming mechanism can be a coil gong of steel, bronze, copper, or brass.   Bells of steel, iron, brass, or bronze.  The most melodic sound will come from the brass, bronze or copper.
The case work of a clock can make or break the look of a clock.  Suffice it to say solid wood and quality carvings become antiques, engineered wood, artificial wood and plastic veneers do not.
Cases can also be of stone (marble or onyx for example) or cast metals.   
Stone and metal cases do not reflect the best value.

When looking for a superior clock, keep the following in mind:
Purchase the best movement available
Purchase a clock that has been properly maintained and professional cared for
If possible a melody clock (such as Westminster chime) garners  greater value than time only
A quality wood case keeps the best value as an antique

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