Hints and Tips ---
Polishing Clock Pivots
Before showing how to polish the pivots, I thought that it would be a good idea to explain why you must use a pivot file and not some other kind! A pivot file has been designed for the sole purpose of dressing hard tool steel pivots. The teeth are of extremely fine cut and the file is much thicker than any other of its size. The file will not bend when in use and the edge is offset so you can get right into the root of the
pivot. I have heard of people using a needle file for this job but I doubt that they will have had much success.
After a while the file will become clogged with steel dust,-sweat,-oil etc, and must be cleaned.
There are lots of ways to do pivot polishing and I will try to give an insight into the ones that I know or have used.
Another way is to make runners from brass rod or steel. An 18" inch length of 1/4" diameter brass rod will cover most common clock pivots and give some spares left over for specials.
Cut the runners into 1 inch lengths and place in the 3 jaw chuck of the lathe, face each end flat. Drill a hole the same size as the pivot and long enough for the pivot you are working on. File the rod to half it's thickness and you have made your first runner! To make a set for future use you can start with a drill size of, -8mm then 1mm, 1-2mm etc up to about 2-6mm.
For the larger arbors, e.g.- fusee and Longcase barrel, you have to use your imagination and ,or whatever tools you have in the workshop! You could of course make a
Jacot tool for these larger items.
Another way is to dress the pivots by hand methods.
Hold the arbor in a pin chuck and support the pivot on a block of wood which has a shallow groove filed into it.
Rotate the pin chuck towards you and at the same time push the pivot file over the pivot, it sounds hard to do, but with practice it becomes, quite easy. In fact some strike lever arbors would be nearly impossible to do, any other way.
Using this same technique you can make your own taper pins from steel or brass wire. Sometimes when using the
Jacot tool, especially on the larger clock arbors, Longcase or fusee for example. The pivot has a tendency to (pick up) while burnishing. This looks like a smear of metal around the pivot and can only be got rid of by using the hand burnishing technique on a block of wood.
There are certain situations which will dictate the setup you have to use but all I can say is NEVER be tempted to use the opposite pivot as the driver while polishing as it will surely end in tears. There again, I could always write an article on re-pivoting!
An article on bushing clock plates-- CLICK HERE A tip on making your own movement holder for clocks under test -- CLICK HERE
HOW TO MAKE A CLOCK WHEEL HOLDING DEVICE
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