Poising a Balance and Positional Error
Tags: balance, escapement, poising, positional error, watch repairs —
One of the important things to consider when regulating a watch is positional error.
Positional error occurs on mechanical watches and can be caused by many factors. These factors could include a poorly sprung balance spring (out of true), a worn or bent balance staff pivot, not enough (or too much) oil on the balance endstones and possibly the balance being out of poise.
If the rim of the balance wheel has a heavy point then we consider this out of poise.
To test for this we need to use some special equipment – the main tool being the “Poising Tool”. A poising tool is a small bench tool which has the facility to be made completely flat by use of height adjustment screws. The tool will have two adjustable jaws and the balance pivots will be rested upon these jaws.

