Tuesday, May 8, 2007

Chicago School Of Watchmaking Lesson 1

Master Watchmaking
A Modern, Complete, Practical Course
By Thomas B. Sweazey and Byron G. Sweazey.

The Chicago School of Watchmaking was founded in 1908 by Thomas b. Sweazey.

LESSON 1: FUNDAMENTAL PRACTICES, EQUIPMENT AND CASING

Section 3:
Master every job and all steps and speed will come with experience.

Section 12:
The first watch was made in 1500. In 1587 watchmaking as an industry was introduced in Geneva, Switzerland by Charles Cusin.

In 1635, enameling was invented by Paul Viet, a Frenchman.

The balance was introduced in 1658. While the minute hand came in to use in 1687. In 1700, jewels began to be used to support gear pivots.

The compensating balance was introduced in 1749, while in 1780 the seconds hand was created.

Section 13:
In 1819, Aaron L. Dennison began building watches by machine. His method of measurement was derived from the English measurement of 1 inch and 30th of an inch.

Dennison used 6|30 of an inch for the "fall". The fall was used by English watchmakers, making the pillar plate small enough to fit into the handmade watchcase.

With 1|30 being the measurement, an 18 size watch would measure 1 inch and 6|30 of an inch for the fall and 18|30 of an inch for the watch size; so the total size would then be 1 inch and 24|30 of an inch.

For watches which are 16 size, down to 0 size, (oh size, or naught size) the measurement is 5|30 of an inch for the fall. So a 16s would measure 1 inch plus 5|30 plus 16|30 making the total measurement 1 inch and 21|30 inch.

Dennison decided to move his factory from Boston to Waltham in 1851.

Section 16:
Screws were used on the pillar plate at the four o'clock position, while a pin was placed diagonally across at the 10 o'clock position in order to hold the movement inside the case, but also to make aligning the 12 hour marker directly center of the pendant easier.

Section 17:
Eventually screws were made long enough, that they could be screwed through both the top plate and bottom plate to hold the movement in the case. The problem with half head screws of tempered metal, is that the constant turning of the screws milled away the portion of the watch case, needing a washer to hold the movement in the case. This was remedied by introducing full head screws, which require removing the entire full head screws from the plates before removing the movement from the case.

Section 19:
The hunter case is comprised of several parts: The front and back lids and the cap are all held to the center by hinges, or joints, the bezel is snapped onto the center.

Section 22:
On snap back cases, a small lip, or cut out is present, so that a thin blade, or case knife may be inserted under the lip, or into the cut out to pry open the front and back. When replacing the front and back lids, the lip, or cut out should be slightly right of the crown.

Section 23:
Shaped cases are built with a key or pin in the center which fits onto the key seat. When replacing the back and bezel, it is important to make sure the key seat is directly over the key.

Section 24:
Swing out cases have a dust proof crown, stem and sleeve. Under the crown is a nut that screws down onto the outside of pendant and under this nut is a leather washer. To make adjustments to the sleeve, you must first unscrew the crown from the stem and then unscrew the nut off the pendant.

Section 29:
In older style cases for lever set movements, there is no sleeve. To remove the stem, you must unscrew the screw located on the pendant just enough, to be able to pull out the stem using the crown.

Section 33:
When trying to remove a movement from a case that is stuck, use the right thumb nail to apply pressure on the movement to ease it out of the case onto your waiting hand.

Section 34:
When taking a movement out of the case, or picking up a movement, be sure to use watch paper to avoid leaving prints on the dial, or movement.

Section 36:
When polishing a badly tarnished watchcase using a red cloth, blow some breath onto the case to moisten it to help with the polishing.

Section 38:
To replace the movement in the case, put the movement in by starting the stem in the winding arbor and fitting the movement into place. Then, while holding the dial side with the nail of your first finger on your left hand, turn the case over and place the movement screws in their slots and screw them in.

Section 39:
Place the crown into the winding position and turn it to be sure the movement is perfectly centered. Then screw in the movement screws just tight enough to keep the movement in place.

TEST QUESTIONS

Assignment No. 2: Sections 12-25

Q1. How are sizes of American watches determined?
A1. American watch sizes are determined by using the English 30th of an inch. An 18 size movement would be 1 inch plus 6|30 of an inch for the fall and 18|30 of an inch for the watch size, for a total of 1 and 24|30th of an inch. A 16 size, down to a 0 size would be 1 inch plus 5|30th of an inch for the fall plus 16|30 of an inch for the watch size, for a total of 1 and 21|30th of an inch.

Q2. What is a case screw and what is its purpose?
A2. A case screw is used to hold the movement inside the watchcase.

Q3. Why are full head case screws considered better than half head?
A3. Full head screws are better than half head screws because the screw is made of milled steel and can wear away the case. A full head screw will not.

Q4. What is the crown and what is its purpose?
A4. The crown sits atop the pendant and is used to set the time and wind the mainspring.

Q5. What is a bezel?
A5. The bezel holds the crystal and sits on top of the watchcase center, protecting the dial and hands.

Q6. Why are screw bezels and snap bezels so called?
A6. A screw bezel screws onto threads located on the case center. A snap bezel snaps tightly onto the case center.

Q7. What is a screw back?
A7. A screw back is a watchcase with threads on the center, so the back may be screwed on.

Q8. What is a back back?
A8. A back back is what the watchcase back cover is properly called.

Q9. What is the center?
A9. The center is the middle of the watchcase where the bezel and back attach to.

Assignment No. 3: Sections 26-40

Q1. What tools are required to remove and replace a movement in its case?
A1. The tools required to remove and replace a movement in its case are a screwdriver, tweezers and watch paper.

Q2. What is the right way to hold and use screw drivers?
A2. The right way to hold and use a screw driver is by holding the shank between the thumb and middle finger, with the forefinger on the top twisting the screw driver with the thumb and middle finger. It may also be held with the top in the palm and the thumb, middle and fore finger on the shank twisting the screw driver.



Q3. What is the correct way to hold tweezers?
A3. The correct way to hold tweezers is by resting them on the middle finger and using the thumb and forefinger on the blades. Also, you may hold the blades between the thumb and forefinger, with the butt of the shank in the palm.



Q4. What steps are necessary to remove and replace a movement in the case?
A4a. To remove and replace a movement in the case, first unscrew the front back and back back, or snap them off, if a snap back case. Unscrew the movement screws and remove them from the movement. Pull the crown out to the set position and lift out the movement, holding it between a piece of watch paper.




A4b. To replace the movement, put the movement into the case by starting the stem in the winding arbor. Keep the dial up and make sure the movement is centered by moving the crown to and fro. hold the case between the thumb and middle finger and use the nail of the left forefinger to hold the movement in place. Use the screw driver to set the screws down tight enough to hold the movement.





Q5. Why should you use tissue when handling watch movements?
A5. I should use tissue when handling a watch movement to avoid getting finger prints on the dial, or movement.

Q6. Why should the movement be placed in a tray and covered?
A6. The movement should be placed in a tray and covered to keep dust off the movement, to avoid losing parts and to avoid damage caused by something falling on the movement.

Q7. How should a case be polished?
A7. The watch case should be polished by placing it in a two sided polishing cloth. Open the cloth like a book to expose the red cloth and rub the watchcase until polished. If the case is very tarnished, breath on it to moisten the case to help the polishing.

Progress Check 1A:

Q1: A man who repairs watch movements is commonly called a___.
A1. Commonly called a watchmaker, or a watch repairer.

Q2. Watches are generally classified as___watches and___watches.
A2. Generally classified as screw back watches and snap back watches.
Watches are generally classified as pocket watches and wrist watches.

Q3. The most important thing about a bench for proper work is its___.
A3. The most important thing about a bench is its height.

Q4. A Master Bench has an___to catch anything that might slip off the bench.
A4. A master bench has an apron.

Q5. Additional means to keep small parts from rolling off are___.
A5. Additional means are a groove along the front edge and a guard rail on the sides and back.

Q6. Watch work is best done on a___surface.
A6. Watch work is best done on a smooth surface.
Watch work is best done on a white gloss free surface.

Q7. The tools used___should be stored nearest at hand.
A7. The tools used most commonly should be near at hand.

Q8. To avoid tiring the eyes, the watchmaker should have___.
A8. The watchmaker should have a loupe.
To avoid tiring the eyes, the watchmaker should have good light.

Q9. Watchmaker's benches have a standard height of___inches.
A9. Watchmaker's bench has a standard height of 38 inches.

Q10. A___set is desirable at the bench.
A10. A comfortable seat is desirable at the bench.
A low seat is desirable at the bench.

Progress Check 1B:

Q1. The first watches were made about the year___.
A1. The first watches were made about the year 1500.

Q2. In 18 size watches, the amount allowed for the "fall" is___thirtieths of an inch.
A2. Eighteen size watch have a "fall" of 6|30th of an inch.

Q3. In 16 size and smaller watches, only___thirtieths of an inch is allowed for the fall.
A3. Sixteen size and smaller watches have 5|30th of an inch for the "fall."

Q4. American manufacturers use___to hold the movement in place.
A4. Movement screws are used to hold the movement in place in American watches.
American manufacturers use case case screws to hold the movement in place.

Q5. The best type of case screw has a___head.
A5. Full head case screws are the best.

Q6. A watch which has two lids or backs is said to have a___case.
A6. A hunter case has two lids or backs.

Q7. When the bezel and back can be snapped on, the case is known as a___case.
A7. A snap case has the bezel and back snapped on.

Q8. Some types of cases must be opened with a___.
A8. A watch blade must be used to open some types of cases.
Some types of cases must be opened with a case opener.

Q9. When both bezel and back screw on, the case is known as a___case.
A9. A screw back case has both the bezel and back screwed on.
When both bezel and back screw on, the case is known as a screw bezel and screw back case.

Q10. Where the movement is contained in a hinged inner ring, the case is called a___case.
A10. A swing out case has a hinged inner ring.

Progress Check 1C:

Q1. The first step in taking a movement from its case is usually to remove the___.
A1. When taking movement from the case, first remove the bezel.
the first step in removing a movement from its case is usually to remove the back.

Q2. Next, the stem is ordinarily___to free the movement.
A2. Place the stem into the set position.

Q3. The width of the screw driver blade should be___the width of the screw head.
A3. The screw driver width should be as close as possible to the width of the screw head.

Q4. Watch parts are preferably handled with___.
A4. Handle watch parts with tweezers.

Q5. ___pressure should be applied to tweezers in working with watch parts.
A5. Light pressure should be used with tweezers.

Q6. You can avoid finger prints by using___in handling the movement.
A6. Use tissue paper to avoid finger prints on movements.

Q7. A movement should always be held by the___.
A7. A movement should always be held by the edge.

Q8. A good habit to form is to place small parts in a___.
A8. Place small parts in a parts tray.

Q9. Cleaning a watch should also include cleaning the___.
A9. When cleaning the watch, also clean the case.

Q10. it is important to___the movement before tightening the case screws.
A10. Center the movement before tightening the case screws.

2 comments:

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Lajuana said...

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