I have this HAC Alarm clock which has been keeping me busy with various faults. It is now ticking happily but the hands don't turn. I deduced that the centre wheel was turning but its arbor was not rotating. I think I understand the construction of the arbor and wheel but perhaps not. As I understand it the wheel must be free enough on its arbor to allow the arbor to be turned by hand to adjust the time but must be attached firmly enough so that the arbor turns with the wheel under normal operation. The spring on the arbor is designed to facilitate this by keeping some tension on but allowing the arbor to be turned without the wheel turning.
With some difficulty and a little violence I have dismantled the centre wheel and installed a substitute spring with a collet to retain it but the problem persists. The wheel is turning too freely on its arbor.
How can I increase the tension on the wheel so that the hands will turn driven by the clock mechanism and also allow adjustment of the time by hand?
Thanks for any advice you can give.