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Commentary about clock repair and clock history from Bill’s Clockworks and ClockHistory.com

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Ansonia Iron Case Mantel Clock with Small Round Movement

September 27, 2009 . by Bill

I recently repaired this Ansonia mantel clock. The case is cast iron with black finish and enamel dial. It is 9 5/8 inches tall, and 11 inches wide at the feet.

The round 8 day movement is 3 1/4 inches in diameter with open mainsprings. It has rack and snail strike on the hour and half-hour. It has a strip recoil escapement.

I did not do a complete repair job on this movement, per customer request.  I cleaned it and replaced the strike click, which had failed. I also replaced the time mainspring, as the existing one was providing at least twice the necessary torque (it was not original). It was 7/16 x 0.018 by 60 inches, and I replaced it with 3/8 x 0.014 by 60″. A longer and thinner spring would have been even better, but not readily available.

The original strike spring is only 0.0125″ thick and is 7/16 inch wide, and 8 feet long. The original time mainspring was probably similar.

Here are movies of the rack and snail strike mechanism and the escapement.

Here is a slideshow.

Repair job 4990.

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Gear Rotation Speed in the Schatz Standard 400 Day Clock

September 25, 2009 . by Bill

I was curious how quickly (or slowly) the various gears in the Schatz standard 400 day clock turned, and especially wanted to know how many rotations the mainspring barrel makes in a year and in 400 days.

Here are the results:

Beats per hour: 480 (8 beats per minute)

The escape wheel rotates every 5 minutes.

The center wheel rotates once per hour

T4 (the wheel driving the center wheel) rotates every 7.5 hours

T3 rotates every 2 days

T2 rotates every 256 hours (10.67 days)

The mainspring barrel rotates every 76 days. It rotates 4.77 times per year, and 5.23 times in 400 days.

Calculations:

First, the number of teeth were counted in each gear:

Barrel 86 teeth

T2 64 teeth (gear) 12 leaves (pinion)

T3 64 12

T4 60 10

T5 (center wheel) 96 8

T6 (escape wheel) 20 8

For all calculations, the center wheel is used as the starting point, we know that it makes one turn per hour. We then multiply a series of ratios to find the rotation speed of the other gears, and the number of beats per hour of the escape wheel.

For number of beats per hour, the escape wheel rotates faster by the ratio of the number of center wheel teeth to the number of leaves in the escape wheel pinion, times the number of escape wheel teeth times 2 (because each tooth of the escape wheel needs to escape twice – from both the entrance and the exit pallet).

Beats per hour = (96 / 8 ) x 20 x 2 = 480

Dividing by 60 minutes per hour gives 8 beats per minute.

For the rotation speed of the barrel, we multiply ratios of the gears driving the center wheel:

Rotation time in hours = 1 hour x (60 / 8 ) x (64 / 10) x (64 / 12) x (86 / 12) = 1835 hours

= 76 days,

corresponding to 4.77 rotations per year or 5.23 rotations per 400 days.

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Schatz 400 Day with Early Logo and Roman Numerals

September 23, 2009 . by Bill

This Schatz standard size 400 day clock was made about 1949 or 1950 in Germany. It has the early form of the Schatz logo on the dial: written horizontally in black (later ones are red and incline slightly). It has Roman numerals instead of the more common Arabic numerals.

When this clock came in for repair most of the gears were rusty and the hour hand was broken off. I replaced most of the gears between the plates (the anchor or verge was usable). Before and after photos are shown below.

Here is a slide show:

Here is a video:

Repair job 4974. Horolovar back plate no. 1278, no date stamping. Uses 0.004 inch thick suspension spring.

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Mainsprings in New Haven Long Drop Clock Movement

September 22, 2009 . by Bill

I recently overhauled this movement belonging to a New Haven wall clock.

Time mainspring: The original time mainspring was broken, and measured 3/4 inch wide by 0.018 inch thick. The replacement is 3/4 by 0.0165 by 96 inches, Merritt’s P-1956.

Strike mainspring: The movement came into the shop with a 3/4 by 0.0142 inch mainspring! It may have been original, but it had a jerky action after cleaning and lubrication. The replacement spring is 3/4 x 0.0155 inch thick (Merritt’s P-1496 in the orange and red box).

The video below shows the escapement action when the time mainspring is run down 7 1/2 days and then fully wound. The motion is sufficient but not excessive.

Repair job 4926.

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Ansonia Walnut Kitchen Clock – Older, 5 Pillar Movement

September 21, 2009 . by Bill

I recently overhauled this Ansonia walnut cased kitchen clock. The strong time mainspring of 0.018 inch thick, was causing wear to the mainwheel teeth, so I replaced the mainspring with a new one that is only 0.0155 inch thick (Merritt’s P-1496 in the orange and red box).

The first video below shows how good the escapement motion is with the thin time mainspring. It is run down 9 days in the video. The second video shows the entire movement in the case and then a closer view of the clock striking the hour and half-hour.

Repair job 4899.

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1880s Cuckoo Clock with Wood Plate Movement

September 20, 2009 . by Bill

I recently overhauled the movement of this clock. The case was in very good condition, it just needed to have a couple of broken leaves glued on and the surface wiped down with wood feeder. I love all the hand carved leaves on the case. The case is missing two finials on the bottom. The clock was made in the Black Forest of Germany.

I polished the pivots, and replaced one badly worn pivot (time second wheel front pivot). The wood movement plates have brass pivot bushings, 3 of them were worn badly enough to need replacing. A previous repairer had bent the warning lift improperly (there are plier marks all over it), it took over an hour to get it shaped properly again.

The front of the movement has an FF trademark on the front. Below are 3 photos, followed by a slideshow of many photos, followed by a YouTube video.

Repair job 4923

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