Long Case #1

This is an attempt at making a wooden longcase clock in the style of a 30 hour clock. It has count wheel striking but sadly a metal bell has had to be used. The ship is animated and rocks gently back and forth. Occasionally it capsizes.

The chain driven movement runs for about 2 hours for a full weight fall  and  12 strike uses most of the length of the clock. The reason for setting up this way is to reduce the mass of the driving weight so as to reduce stresses on the mechanism. The driving weight used is 500g.

Because of the necessary frequent rewind an automatic electrical rewind has been fitted. This comprises a motor and two pin dog clutch driven into engagement with a spiked wheel to pull the chain. This happens once an hour just before the strike and continues until the weight passes an optical sensor.
Interestingly this system could be fitted to an existing antique clock in a completely reversible way with no damage to the clock. The auto wind is shown in an image below.

A general view of the mechanism

The mechanism an be viewed as three sections. The motion work and date wheel are on the left with going train next right, followed by the striking train and the count wheel just visible on the right. The ratchet for the wind mechanism is built into the chain wheel seen in the centre of the image. 

 

 

The autowing mechanism. The rewind motor is the yellow object which is driven into engagement by a radio control servo at bottom right.

 

The dial is a high quality photographic print glued to a plywood dial plate.

 

 

All in all it has been very successful. The timekeeping part of the movement works well and the striking section, although noisy when running is very reliable. The autowind is brilliant.