Connecticut type American antique clocks are known for being over-powered. The one-day clocks often have more than 3 times the least amount of power necessary to run the clock.
One of my Chauncey Jerome 30 hour OG clocks was missing its weights when I bought it, and so I experimented with weights. I found that the time train of the clock would run reliably on 1 pound! (Normally these clocks have about 3 to 3.5 pounds on the time side). The strike weight usually weighs around 2.5 to 3 pounds.
I recently repaired an early Seth Thomas 30 hour Ogee. The weights that were with the clock when I received it are 2 pounds 9 ounces and 2 pounds 10 ounces. They look old and match each other in appearance, but there is no way to know if they are original to the clock. The strike sounds fine with this amount of weight, and the pendulum and escapement take an excellent motion. Here is a video showing the escapement in operation. Note the generous amount of overswing or supplementary arc (how much further the verge moves after an escape wheel tooth lands on one of the pallets):
This clock will run for a short time with a 7 ounce weight on the time side, with almost no overswing. There is noticeable overswing with 9.8 ounces of weight, and with 1 pound weight the overswing is small, but enough. With 1 pound, 12 ounces, the overswing is quite good. Of course, a clock movement must be in excellent condition to run with this little weight.
The striking sounds a little slow, but acceptable, with 1 pound 12 ounces of weight. The striking will run with 1 pound of weight, but it sounds WAY too slow.
I plan to wind this clock daily (it is on a workbench at my clock shop), and will run it with a 1 pound time weight and a 1 pound 12 ounce strike weight, to reduce wear in the movement.
Update
From June 30, 2009 to February 10, 2010, it ran continuously on the 9.8 ounce time weight. Then, it would occasionally stop around 10 minutes before the hour (when the strike levers are lifting). On February 13, I started running the clock with a 15.6 ounce (440 gram) weight.
I just repaired this beautiful and impressive French mantel clock. The clock is 25 3/8 inches wide and has 2 matching candle holders. The visible escapement and black dial chapter ring are very good looking.
The only major problem with the clock was that the mainspring hook in the strike barrel had pulled out. I securely re-riveted back in place, after flattening the area around the hook, which had bulged. I also tightened the hook in the time barrel.
A common problem with French clocks is a torn hole in the outer mainspring end, but in this clock the mainspring ends were fine.
Here are videos of the escapement, and the clock striking:
I recently repaired this clock and polished and lacquered the base and pillars. Diamond dial clocks are not as common as those with round enamel dial. This diamond dial is unusual in having a picture (beehives and beekeepers) instead of a silver background. I cleaned the movement, polished and burnished several of the pivots, and replaced the suspension spring. This clock runs extremely well.
The movement is dated 10 52 (October 1952) and is Horolovar back plate number 1281.
I recently repaired this clock and polished and lacquered the base and pillars. Square dial clocks are not nearly as common as those with round enamel dial, and slightly less common than the silver diamond dial. I cleaned the movement, polished and burnished several of the pivots, and replaced the suspension spring. This clock runs extremely well.
The movement is dated 2 53 (February 1953) and is Horolovar back plate number 1281.
I recently repaired this clock. It needed a new ratchet wheel and a new second wheel. The mainspring was stronger than necessary (3/4 inch wide by .018 inch thick) so I replaced it with a new spring 0.0165 inches thick and 108 inches long.
This clock has a Graham deadbeat escapement, with the adjustable pallets mounted between the two brass pieces that form the body.
The oak case is 52 inches tall, 20 1/2 inches wide at the top, 16 15/16 inches wide at the door, 10 inches deep at the top and 8 1/4 inches deep at the door. The dial is made of aluminum, and is 13 inches square, with a 10 7/8 inch time track.
I just serviced an E. N. Welch “Arditi” perpetual calendar clock. I disassembled the movement and cleaned it, but the only repair was replacing the click rivets, as the original brass rivets were coming loose.
This clock has a 27 3/8 inch tall walnut case, and was made in the 1880′s. The movement has very old mainsprings which appear to be original. They are thin (0.0153 inches thick for the strike spring and 0.0156 inches thick for the time spring) and do not seem very “springy”. Yet, they provide plenty of power and have no visible damage, and so I kept them in the clock. If a mainspring has lasted for over 120 years, it is likely to keep on working.
The video below shows how well this clock runs, even with the weak mainsprings (and it is run down several days, not fully wound).
One interesting thing about repairing 400 day clocks, is that they almost NEVER need bushing. The few that have come into my shop with bushings installed by a previous repairer, would have been better off if they had not been bushed (because the bushings were installed off-center and were too tight on the pivots)!
The gears in 400 day clocks turn so slowly that the pivot holes wear very little. A 100 year old 400 day clock that has been running for many years might possibly need a bushing or two, but it is a bad idea to routinely bush 400 day clocks.
Many 1950′s 400 day clocks (especially the Schatz) can benefit by having some of the pivots smoothed and burnished. Take a close look at the pivots after cleaning, and quite often the the second, third and fourth wheel pivots will show slight pitting. Smooth broaching the pivot holes (using an oiled round broach) is also a good idea.
As the 1950′s began, most (if not all) 400 day clocks in production were “standard” size, with movements about 2 5/8 to 2 3/4 inches wide. In the early to mid-1950′s, companies including as Kundo and Schatz designed “narrow plate” standard movements slightly less than 1 3/4 inches wide that could be imported into the USA as a “watch” instead of as a “clock”, with a lower import duty. From that time on, the Kundo standard 400 day clocks had the narrow movement. For a reason unknown to me, Schatz made their narrow plate movement for only a short time, and then reverted to their wide movement. Thus, the Schatz standard narrow movements are not very common.
I recently repaired this Schatz narrow plate clock. It has Horolovar back plate no. 1291A, dated 7 – 53 (July 1953). The movement has 2 jewels. It has model number 49R in a circle on the back. The movement has a thin brass plate screwed to the back to make it appear wide.
This example has an extra barrel and mainspring, which was intended to equalize the power to the escapement (but as far as I can tell, it did not provide any improvement). This feature is occasionally seen on examples from the early 1950′s.
