Small Grande Sonnerie Desk Clock 

As received, this small Grande Sonnerie desk clock would run but would not chime automatically and would not repeat on demand.  It did make a whirring sound of the strike train wheels turning.

The brass case was missing one of the round brass feet, which have off-center screw holes.  The movement out of the case was beautiful and looked unmolested.

The sonnerie quarter and hour racks were not falling because of gummy old oil.  I cleaned them and the pivoting posts and it now works fine.  In addition, the gongs were out of place and the hammer rebound needed setting, but now it chimes the time beautifully on the hours and quarters, and on demand with a push of the top button.

To make the missing brass cabinet foot, I curt down a large brass rod to the right diameter and cut a recess in the end for a new felt pad.  Then I parted the new foot from the rod.

To drill a double off-center hole for the screw in the new foot, I had to set up a left handed faceplate lathe head opposite my regular lathe head to hold the new foot exactly off-center and steady where the new hole would be.  I drilled through once for a hole for the screw and a second time, larger and shallow, to inset the screw head into the new foot.

 Now I had a new cabinet foot.  I had found a screw with the right threads, but the head was much too large and the screw far too long.

Back to the lathe to cut the screw head down to size.

And measure and cut the screw to the right length.

 Now the new foot fit the cabinet, but all 4 feet needed matching felt pads.

Easily solved with felt pads from Home Depot.

And cut down to size to fit all 4 feet.

With the new cabinet foot, felt pads in place and regulating the timekeeping, the repair was complete.

 
 

 

 

Enamel Silver Minute Repeater Repaired:

This minute repeater was non-running, would not wind or set and the repeater was not working  as received.  Initial investigation showed the following:

A: Repeater operating lever has non-original operating slide that is too short and too rough to operate the  repeater.

B: Clutch wheel operating lever out of wheel slot.

C: Non-original trip dog keeper.

D:  Slide sticky and stiff.

E:  Major problem is the minute wheel is missing 6 teeth, has one poorly replaced tooth and one tooth damaged by filing.  Plus, the center pinion is missing one leaf (tooth).


Repairing the repeater (A:)
The repeater operating slide required making a new slide because the current slide was too short to achieve striking beyond 7 hours and too  rough to run smoothly.  A suitable piece to high quality steel of the correct gauge was found to be a piece of a large case knife snap off blade.

The blade piece was heated to red and allowed to cool slowly to remove the temper and a 0.5 mm hole was drilled for the screw-in post.

The hole was tapped for a screw.

A screw had to be made from scratch for the right size and shape new post for the slide, first turning steel stock on the lathe.

and then making the threads with a screw die.

The finished screw will have the head filed off after it is in place and spot welded from the bottom, leaving a strong steel post in the slide plate.This 0.5 mm screw will have to take all the pressure of a person's thumb or finger operating the repeater slide of the watch.







The slide was shaped and the post installed and then the slide and post were both hardened and tempered for strength.










On reassembly, the repeater worked.








Fixing the clutch wheel lever (B:) was simple to do by loosening the hold-down screw and moving the clutch lever into the clutch wheel slot.  This let the winding and setting system work.

Checking the operating of the hammer trip dogs showed that the non-original keeper (C:) worked fine  as it was.

The sticky repeater slide (D:) was fixed by cleaning rust off of the internal slide and shaving it down slightly to allow it to clear the case braces in the slide channel.

Fixing the minute wheel and center staff pinion (E:) was a major undertaking.  First, with the set lever working, I checked to see if the minute wheel would still set the time by spanning two leafs on the pinion as it went past the missing leaf, but it would not.  The specifications for both wheels were so tight and unusual that no suitable replacements could be found.  This meant that teeth would have to be repaired on both the minute wheel and center pinion. On a minute repeater, this part is not a true canon pinion and it is an integral part of the repeater minute snail and surprise piece assembly.

A suitable larger brass wheel of the right gauge was selected for the damaged wheel.

The donor wheel was cut down on the lathe to the right diameter. 

Then the wheel cutting and indexing attachments were set up on the lathe to cut new teeth on the wheel blank.  This was a 36 tooth minute wheel.

New teeth were cut.

Next, a rounding up machine was set up and aligned to shape the tooth profile of the  new teeth correctly and the wheel was machined until the tooth profile and wheel  diameter was as required.












The new wheel matches the damaged wheel. Only the teeth will be used as the center pinion does not match the old wheel.











Good teeth are cut from the new wheel to replace bad teeth on the original wheel.












Bad teeth are cut away from the original wheel and the new teeth carefully matched in place.











The new teeth are soldered in place with heat from below so solder is wicked into the entire joint.











Solder is filed flat and the wheel tested for strength and true.

 Repairing the center pinion: 
The pinion staff and shoulders for the repeater snails are cut from a single piece of steel so the pinion can not be replaced. 

First, the surprise piece with quarter snail is removed and then the minute star snail is removed from the arbor by breaking the staking rivet.












New metal is microscopically welded onto the broken pinion.  18K solid gold is used because it flows and welds to the steel strongly and it is hardened by the welding process.   Gold welded onto steel is surprisingly strong.

















A new tooth profile is filed from the gold.

















The minute star snail is riveted (staked) back on to the arbor against the center pinion and tested for strength.  Then the surprise piece with quarter snail are re-assembled and tested.

The repaired minute wheel and center staff pinion are re-installed and tested.  Now the motion works runs correctly, the  time can be set and the minute repeater works correctly.




Total time spent was 11 hours, 15 minutes (not counting any time to take pictures and type the blog).

18K Two Train Grand & Petit Sonnerie With Trip Repeater

With Signed Original Wood Case including 2 alternate original dials

Beautiful carved and engraved massive 18K hunter cased Grande Sonnerie.  This watch by C. A. Montadon from Locle, Switzerland has a tandem wind 37 jewel movement with diamond endstones is a Grande & Petit Sonnerie and trip repeater which will chime the hours and quarter hours as time passes automatically.  The fully jeweled movement will chime the hours every hour by itself and will chime the hours and quarter hours every quarter hour (Grande Sonnerie).  It has 2 switches on the bezel; one for sonnerie or silent, and another to select Petit Sonnerie or Grande Sonnerie.  In the petit sonnerie mode the watch strikes the hours every hour, but at each quarter hour it chimes only the 2 tone quarter strikes without the hours, much like many striking clocks.  Winding the watch crown clockwise winds the watch and winding it counterclockwise winds the sonnerie.  There is a button in the edge band that, when pressed, makes the watch strike the hours and quarters on demand.  The case, dial and movement are all in very good working condition, correctly chiming the hours and quarters as time passes.  The watch is signed C A Montadon on the case, the movement and the original wood box.  The box has an inlaid brass shield and contains a spare alternate silver engraved dial and a clear glass dial with gold index numbers to display the magnificent complicated dial side of the movement.  The silver dial is very similar to many other dials like this on other C A Montadon watches from this period.  The clear glass dial has gold index numbers that are very worn because the numbers are on the outside of the dial where they were touched and cleaned by prior owners of the watch.

18K Minute Repeater with Perpetual Calendar

Excellent condition 18K hunter case minute repeater with perpetual calendar and moonphase.  The movement is signed by Samuel Lyon Jr., 57 Church Street, Blackpool, England.   The full plate movement is fully jeweled through the hammers with an English side lever escapement.  Movement, case and dial are all in excellent condition and all functions work correctly.  The massive 18K solid gold hunter case has no monograms or personal engravings.  The repeater slide is actually inset into the gold case band so only the operating edge of the slide shows, instead of the usual larger slide on other repeaters.  The perpetual calendar uses English language.