Swaging a setting button
If you repair many alarm clocks, as I do, you will sooner or later come across one without an alarm-setting button. If a push-on setting button is required, you don’t have much of a problem. You may be able to find a suitable replacement in your box of odds and ends or, if not, a visit to your parts supplier will solve the problem. If a screw-on button is needed, finding a replacement could be more difficult. The internal thread required may not match any available tap and may even be left-handed.
Recently I was faced with such a problem. I had a brass push-on setting button which would just push on to the threaded end of the steel alarm setting arbor, but how could I modify it to screw on to the arbor? Swaging was a process that came to mind. This is the squeezing process used to attach the fittings to the ends of stays and halyards of sailing dinghies and also to attach the ends to speedometer cables when one buys a cable in kit form.
I set the jaws of a pair of ‘Vise-grip’ locking pliers to the outer diameter of the setting button and then turned the adjusting screw to limit the travel of the jaws to about 1mm. I placed the threaded end of the alarm setting arbor in the hole in the setting button, positioned the pliers so that a jaw was on each side of the slot in the winding button, and squeezed.
The result was pleasing—the setting button could now be screwed on and off the arbor. When the arbor was replaced in the movement and the swaged setting button screwed on, it worked perfectly. I now know that it is possible to reproduce any internal thread, right-handed or left-handed, in a brass setting button and the process is probably applicable, with some modification, to brass winders as well.
Alf Wilford, Australia
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