The Micrometer

A two-monthly review of the engineering of time

Issue 11   May - June 2018

The science of mainsprings

     For some months now I have been undertaking a number of trials to assist me in my understanding of how a clock mainspring 'works', which is not helped by many horological texts lumping together the theory of mainsprings and balance springs.  While superficially the way they work may seem similar, they are not.

     Take, for example, the matter of mainspring length where these texts generally imply that the 'strength' is inversely proportional to length.  It is not, as a glance at my measured torque v. turns graph of the same spring cropped to three different lengths clearly shows.  For all three springs, the maximum torque is of the order of 110,000 gm.mm, whereas if it were inversely proportional, the 400 mm (second) spring would provide 4½ times the torque of the 1800 mm (first) spring.

 

     Over the coming months I hope to go into more detail, but for those who are interested in the reasons behind my iconoclastic interpretation: "Think strain, not stress".

Guy Gibbons

Copyright (c) 2018  G E Gibbons     If you do not see the updated pages you expect, try again after by-passing or clearing your browser cache.  Guidance may be found at https://en.wikipedia.org/wiki/Wikipedia:Bypass_your_cache

The Micrometer

A two-monthly review of the engineering of time

Issue 10   May - June 2018

The Micrometer

A two-monthly review of the engineering of time

Issue 11   May - June 2018

Copyright (c) 2018  G E Gibbons        If you do not see the updated pages you expect, try again after by-passing or clearing your browser cache.  Guidance is at https://en.wikipedia.org/wiki/Wikipedia:Bypass_your_cache