From the SLBBHI Workshop

londini

We thought it may be interesting to show some of what as been going on in the SLBBHI workshop during the evening classes.

Let me first set the scene. The class is made up of a mixed bag of ‘students’ with a range of abilities including those with many years of prior horological experience, through to myself with almost none. So far, each student brings in their own projects to work on. Each gets individual attention from Ron and, on welcomed occasions, James, with advice on how to proceed, problem solving, associated history, and subtle encouragement for further study. The evenings are frequently punctuated by talks or demonstrations given to the whole class by Ron. Everyone takes an interest in the other students’ projects. In this way the learning opportunities are frequent and cover many aspects. I am looking forward to the next class before I have left the current.

Onward! To describe a project, chosen just because it is mine, and my first ever dabble in the practical aspects of clocks:

The subject is a weight-driven winged lantern clock by Thomas Dyde, Londini, probably dating from around 1660’s. It has been in my family for about 50 years. It has not been cleaned or given much care since it was first restored after being purchased as a box of blackened parts from a shop while on family holiday in Yorkshire. For most of those years it has been running and I have childhood memories: of it’s tick; of watching the pendulum swing in and out of the windows in the wings; and of raising the weight and the pleasing sensation feeling the click while pulling the rope. In recent years it had become tired and would need to take a nap after a few minutes of running. So, it has been temporarily entrusted to me to enliven.

At the start, I had no intention of writing about it so I don’t have any pictures of the initial condition. On first opening the sides it became clear what the probable cause of it’s unreliable performance was: cobwebs and the remains of a diverse range of arthropods. The attention of a 2″ paint brush completed the problem solving but I took the opportunity to dismantle, clean the components with lighter fluid, remove surface rust from the iron components with a fiber-glass pencil, reassemble, and oil. Here are some pictures of the result, with some comments on things I learned, with Ron’s help, along the way.

Lantern Clock

So you can see what I’m talking about, here is the clock, cleaned, and in the sun.

 

 

 

 

 

 

The first point of interest along my journey that I want to share was the minute-hand wheel. The hand sits over the square end. In it’s current state, the hand is held on by a washer and a pin through the steel shaft which the wheel rotated on. However, Ron notes that originally the hand would have been held with a clip that sits in the groove in the square end. The first clue to some changes the clock has seen over the years. The wheel also shows signs that the strike pin has moved and that a tooth has been replaced due to a stress crack that started at the original location of the strike pin. (click pictures for full-size)

minutewheelminutewheelend

Another example of a replacement tooth, and the first I noticed, was not dovetailed as the minute-had repair has been, but instead has a round mortice profile. This is on the wheel that takes the weight (I’m not up to speed on terminology yet, despite being told).

roundmortice

This wheel also shows signs of alterations. The click stop has been upgraded from a latch spring that would have engaged the wheel spokes (and there is considerable wear on these as evidence) and given a ‘stop’ every quarter of a turn of the wheel, to a more fine latch on a new wheel mounted alongside.

 

More on the subject of stress fractures in cast  brass, here is a repair to a crack…

crackrepair

In detail, a stress-relieving stop hole drilled at the end, and a supporting plate riveted in place. It seems that the crack may have been aggravated by a replacement bush:

 

crackclosecrackrepairclose

Someone in the past, who perhaps wanted to avoid riveting a replacement bush in a material prone to cracks, has opted for a more raw blacksmith technique to close up an oversize hole. (By the way, Thomas Dyde had a blacksmith apprenticeship  and was not known to be a member of the Worshipful Company of Clockmakers so in some way this seems appropriate here but probably not generally recommended for fine clock restoration!) The metal around the pivot hole has been ‘moved’ to close up the hole by using a round punch around one section of the perimeter. The punch has been applied to both sides of the hole.

alternativetonewbush

There are more photos available on Google+

One Reply to “From the SLBBHI Workshop”

  1. Great post Jack, many thanks!
    The minute hand is a rare and interesting feature to the clock. I like the outer minute chapter which shows the quarter hours only, it suggests that the clock was only ever expected to be accurate to around 15 minutes when new.

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