Maine Chapter 89, NAWCC

Clock Repair Course and F101 Class 1

 

The Community Room, Senior Health Center, 58 Baribeau Drive, Brunswick, Maine. [Directions]

Saturday, April 19, 2008

9:00 a.m. to 4:00 p.m.

Proposed date:  February 16, 2008

Workshop Leader: Br. Mark Beever

 

Workshop 1:  

Introduction to the common American time and strike movement,  typically found in a "Kitchen Clock", including the identification of parts, inspecting, and diagnosing problems.

Captivation of mainsprings and letting down power, Movement Disassembly, Clean Mainsprings, Clean Movement by Hand.  Note:  We welcome you to jump in where you like.  We would prefer, however, not to take the rest of the class backwards, so we ask you to be competent in the previous workshop skills. 

Repair of the common 8-day mass-produced American clock is foundational to repairing all other types of clocks.  We will truly exhaust every detail of this movement over the coming months.  With these fundamental techniques as credentials, you’ll be prepared to tackle some of the finer, complicated and no-so-common movements.

Materials needed (minimum):

8-day American count-wheel type striking pendulum movement with winding key

Safety glasses or safety goggles (no exceptions please)

24 inches 16 gauge steel wire or two hose clamps (12 inches in length)

Household two position slip joint pliers

Flat blade screwdrivers (one with 1/8 wide tip, one with ¼ wide tip)

Plastic dishpan (approximately 10 x 12); a hospital wash pan would be ideal

6 sheets of paper towels

Notebook, pen / pencils (to make a sketch of the layout of the gears)

Small wad of 0000 fine steel wool

2 pair surgical gloves

1 pair leather gloves

Sharpie black pen (fine tip)

Old toothbrush, a few Q-tips, some round toothpicks, and a couple of chopsticks, sharpened to a point.

We will provide:

Let down key set

Mainspring winder

Vice

Cleaning solution

Compressed air source

Mainspring lubricant

Stuff you might forget

During this workshop module, each of us will captivate the mainsprings and safely let down the power using a minimum of common hand tools.  This will be done using the stock winding key that comes with your movement.  Be sure it is good fitting. 

One of the clock plates will be removed.  At this point, you’ll make a sketch of your movement BEFORE removing the gears and levers.  In your notebook, make a tooth and pinion gear count of each wheel.  We will need this information later on.  We will review the names and functions of each clock part.

As time permits, we will clean each piece of the movement, making note of worn bushings and relationship with respect to wear.  Drawing out each mainspring, we’ll properly clean and lubricate.

This document as well as all other available handouts are posted at:

http://www.nawcc89.org/workshop/F101.htm

 

Typical 8-day time and strike pendulum clock

 

 As we review the parts of the clock together, fill in the name of each part below.

A	G
B	H
C	J
D	K
E	L
F	M

Additional hints:

 

How to release the mainspring power using your wits and a winding key

The power in mainsprings MUST be carefully released before anything is done to the movement.

Even if you think there is no power, there could be sufficient tension in the trains to cause you a great deal of embarrassment, damage to the gear teeth as well as tearing up the flesh on your fingers. 

After winding up the mainspring to “almost there”, install a hose clamp around the mainspring and movement post.  Don’t over-tighten. Alternatively, you can replace the hose clamp with a spring "C" clamp around the spring alone.

It can be helpful to have a spare set of hands  available.  Use a well-fitting key.  While holding the clock movement in one hand, take up the spring tension slightly with the key and gently release ratchet click from the ratchet wheel.  You may be able to do this ¼ turn at a time, or more safely one or two teeth at a time.  Repeat the process until all of the power is contained within the hose clamp.  At this point, you should not have any torque in any of the gears in the trains. 

Remember, one slip and it’s major damage.

And now you know the reason why I use a set of “Let-Down” keys.  As an alternative, one can modify a 4 inch long piece of 1-inch diameter wooden dowel.  Drill a ¼ inch hole down through the center approximately an inch deep.  Next, saw a slot across the diameter at the same end where you drilled the hole.  The slit should be wide enough to permit the winding key to fit into the end of the dowel.  I’d also advise that you spin the other end of the dowel and remove any sharp edges.  Now you have a home-fashioned let down key.