lining up escape wheel pivot holes

[willofiam]

Thought I would share this even if it is common knowledge. Many times thru previous work on a clock or by just plain old abuse the brass piece that holds the pivot outside of the main plate for the escape wheel becomes twisted if not just a tiny bit , using a technique I used in building orthotic braces with joints you have to line up 2 holes perfectly parallel to each other or else they will bind. In the case of a escapement set outside the plate the 2 pivot holes need to be exactly parallel in all directions (this is true with ALL pivots) but here we can make the adjustment. Place the plates together and tighten with the screws or nuts just as if it were assembled. Using a piece of pivot wire or anything round, straight and long enough as close a diameter as the hole as a guide, pass the rod thought the escape wheel side with the angled brass piece “arm” and trace a imaginary circle around the corresponding hole on the opposite plate. Notice whether it is circling the other hole equally all the way around or not. If not then make the adjustment accordingly to the “arm” and test again. once it looks proper put the escape wheel in and check the end-shake (must have some end-shake) if all is lined up then give it a spin and see if it runs freely, if adjusted right you will have a smooth running escapement. This also works well on the exposed escapement and any other areas where there can be an adjustment made to line up holes.

[arutha]

Great idea William,
just make sure whatever piece of wire you use is perfectly straight otherwise this could cause a problem. I like to check my escape wheel pivots by chucking them up in my watch makers lathe and then lining them up with the tail stock. Once you know the arbor and pivots are true you will soon know if there is a problem with the plates. It is not unknown for a previous repairer to do a bushing and move the centre of the hole enough to make the wheel bind. If this is the case you can plug the incorrect hole with brass wire and then find the centre again by using the other clock plate for reference using a pair of dividers and using two holes that run to and from the wheel that would be in the hole that is incorrect. If both sides have been done badly you will struggle unless you have a depthing tool.
Paul.

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