I would like thiSeiko. Has the slowest movement ever. 1 revolution per year.

[Robert Gift]

 

[Willie X]

Day, date, moon phase, month, and local time. Not sure about the "1 revolution per year"?? Willie X

 

[Robert Gift]

Day, date, moon phase, month, and local time. Not sure about the "1 revolution per year"?? Willie X

The month pointer does 1RPY!
Seeing the back it appears all mechanical from a battery-powered quartz motor.

 

[J. A. Olson]

Looks like a typical Quartz movement plopped atop a plastic gear reducer platter for the moon dial and day/month hands.
Seiko did many specialty Quartz clocks and they are usually unserviceable when they stop working.

 

[Steven Thornberry]

The month pointer does 1RPY!

Nothing particularly surprising or new (or slow) about. Here is an Ingraham Calendar with B.B. Lewis's calendar movement, whose month pointer also does one RPY. After all, how fast should it move?

 

[wisty]

I have a French mantel clock with a Brocot perpetual calendar. There is a wheel in the calendar mechanism that rotates once every four years to manage the leap years.

 

[Robert Gift]

I have a French mantel clock with a Brocot perpetual calendar. There is a wheel in the calendar mechanism that rotates once every four years to manage the leap years.

Wow! Wonderful!
Would love to see that and the B.B. Lewis calendar movements.
At least I could possibly own that Seiko.

When did mankind begin to add leap days? (Manyears ago I was excited to hear a leap second on WWV!)

 

[Robert Gift]

Looks like a typical Quartz movement plopped atop a plastic gear reducer platter for the moon dial and day/month hands.
Seiko did many specialty Quartz clocks and they are usually unserviceable when they stop working.

Would silicone spray help?

 

[Robert Gift]

Nothing particularly surprising or new (or slow) about. Here is an Ingraham Calendar with B.B. Lewis's calendar movement, whose month pointer also does one RPY. After all, how fast should it move?

View attachment 736437

Do the day and month pointers click to thext day and month?
(In the upper dial the day pointer is too advanced for the time indicated.)

 

[Robert Gift]

For what?

Spraying on the plastic gears and their axles to free them if stuck.

 

[Robert Gift]

You haven't been reading much about oiling clocks then have you?

No.
On our mechanical clocks I use Mobil1 full synthetic 0W-20 motor oil.
Is there something better than silicon spray for plastic gears and axels?

 

[J. A. Olson]

What happens is the Quartz movement eventually stops working and cannot be disassembled the way that most mechanical movements can be disassembled for servicing. Too many cheap plastic parts which break as soon as you try to take everything apart. Plastic gets brittle with age so it's worse when you're trying to work on something over 20 years old.

The best that may be done is switching out the movement for a replacement and that isn't always guaranteed to fit.

 

[wisty]

Would love to see that

As requested, a picture of the calendar movement with some notes. Sorry about the poor quality of the dial photo, it's the only one I have to hand.
The calendar movement is actuated once per day via a drive rod (top left) from the strike train in the clock. The strike train has a disk with a pin on it that rotates once per 180 strikes (One day including half-hours - it is a pig to get to operate at midnight!).
The drive rod moves three actuators. A Day actuator that steps the day wheel on one day (7 teeth); a date actuator that steps the date wheel on one day (31 teeth) and a short month's actuator that moves every day, but only does anything once per (some) month. There is also moon phase gearing (the fine-tooth wheel is just visible) driven from the day wheel.
The months cam in the centre ( which also carries the central hand) resembles a count wheel. It is geared to the date wheel, rotates once per year, and has notches for the 30-day months plus February at 28 days. As pictured the follower is sitting in a 30 day notch.
At the end of the month, the pins (currently shown at bottom left) will have rotated (anticlockwise) round to be aligned with the face of the short months actuator. There are three pins one for 30 day months, one for 29 day months and one for 28 day months (hidden behind the setting wheel).
Depending on the month length the Month's follower lifts or lowers the Month's control lever which lifts the short months actuator to clear or catch the appropriate pin. In 31 day months the actuator lifts clear of the top pin and on the 31st of the month the date actuator rolls the date over to the 1st. In 30 day months the short months actuator catches the top pin on the 30th and pushes the date wheel forward 2 days to the 1st. In February of non leap years the actuator is fully lowered, catches the third pin on the 28th and pushes the date forward by four days from the 28th to the 1st.
Once every four years there is a cam on a wheel between the Months cam and the Moon gear which appears in the February notch and lifts the follower so that the short months actuator doesn't catch the 28 day pin - so the date goes on to the 29th, but the following day catches the second pin and pushes the date on by three days.
I have not dared take it apart. Getting all the wheels back in the correct relationships strikes me as a nightmare.
Hope this is useful to someone.

PS On the subject of leap years look up Julian and Gregorian calendars.

 

[Burkhard Rasch]

When did mankind begin to add leap days?
afaik the julian calender introduced by Julius Caesar in 45bc used leap years , and probably these were introduced by the late egyptiens in the calender even one or two centuries before that time.
Burkhard

 

[Burkhard Rasch]

btw if You look for slow revolving gears look at the astronomic clock in Straßburg/France : it contains a wheel turnin once in about 25700 years to demonstrate the so called Platonic year , the circle of the precession of the eath´s axis. That´s what I call slow turning!
Burkhard

 

[Robert Gift]

btw if You look for slow revolving gears look at the astronomic clock in Straßburg/France : it contains a wheel turnin once in about 25700 years to demonstrate the so called Platonic year , the circle of the precession of the eath´s axis. That´s what I call slow turning!
Burkhard

Depressing. None will geto see it move.