This is Part I of a three (3) part series. In Part I I discuss disassembly and servicing the mainsprings. In Part II, the movement and in Part II restoring the brass case.

My wife found this 1910 Ansonia Crystal Regulator in the late summer 2018 while antique shopping. In the 1905 Ansonia Crystal Regulator catalogue it is listed as the Prism at a price of $29.00 which would have been a hefty sum at that time. (Flash is required to open the catalogue)

What a great choice! We were in a hurry and should have asked the proprietor to show us that it worked. We returned home and to our dismay, it was not running. As I said in an article published in Dec 2018:

A gentle push of the pendulum produces a few ticks and then it stops. I am not familiar with Brocot escapements and before I do anything I will research the movement before I disassemble it and give it a thorough cleaning.

Brocot visible escapement; in this photo, the brass is very tarnished
Just days old but I thought I would polish the brass

This is a truly beautiful clock with a visible escapement. What I have learned is this; don’t mess with a Brocot escapement. The stone pallets, which are made of garnet are very delicate and breaking one or both is a huge issue. The pallets are held together by melted shellac and cleaning them in an ultrasonic will loosen them as they are position sensitive.

It is now April (2019) and I have put this project off long enough. So let’s begin.

This not a particularly easy clock to work on. The pivots are smaller than a typical American time and strike movement which means closer tolerances. The strike side is rack and snail, that is, there are no helper springs and only one combination lever between the plates. Most strike parts are located outside the plates and the final assembly for the Brocot escapement also occurs outside the plates. There are two wheels with stop pins for the strike side. Setting them up can be a challenge.

Dissembling the case

To disassemble the case I wrapped two strips of painters tape on all four sides. Doing so prevents the glass from falling out. Beveled glass panels are difficult to replace and exercising care when working with the case will prevent accidents. Each glass panel can be as much as $75 by the time shipping is included and turnaround time can be as much as 2 months.

The first to come out is the gong assembly. One large nut secures the gong to the case and is accessible from underneath the base.

I chose to disassemble the entire case though it is possible to remove the movement without doing do. There are three screws at the 1-2, 10-11 and 6 o’clock positions though a long skinning screwdriver is required to get at them.

There are 4 large screws on the bottom and 4 on top. Unscrew the bottom 4 screws first. Once the base is off you will quickly realize the importance of the painter’s tape. To access the top screws there is one small screw underneath the top plate that must be released to access the 4 top corner screws. Patience is key if you work slowly the chance of error is reduced. Put the brass pieces and the glass panels in a safe place while working on the movement.

Mainsprings

The mainsprings are in barrels. The barrels are secured to the movement plates with 4 screws. The great wheel and the arbour are one piece. With a twist, the arbour can be removed from the mainspring.

There are three ways to service the mainsprings.

1) Find a temporary winding arbor and use it to unwind the mainspring on a spring winder.

2) Hold the barrel in one hand and pull the spring out with the other being careful not to kink or bend the spring. Once the spring is released from the barrel, unhook it and you are free to clean the spring. To put it back together, use a thick leather glove to hold the barrel, hook the hole end, and carefully rewind the spring back into the barrel.

3) Partially disassemble the great wheel and use the arbour without the gear in place. Special tools are required to separate the arbour from the wheel.

Olie Baker spring winder
Olie Baker spring winder
Front of movement showing visible escapement
Back of movement showing rack and snail, hammer and rate adjuster

In Part II I discuss servicing the movement and in Part III, restoring the brass case.