Re: Sticking reset

Ian Richardson

Hi Brian,

There is an ancient proverb which says, "if all else fails, read the instructions".

Others may contribute, but for a start I attach a pdf file of a sketch I made years ago showing the settings for the buffers, air gaps etc.  As your current seems to be correct, maybe you could try adjusting these settings.

The only other thing is to try slackening the gravity arm return spring.  Finally, make sure that the rest buffer is clean and that the armature isn't sticking to it.  Other than that, I've noting more to offer.

Good luck,
Ian R
Auvergne, France

-----Original Message-----
From: Brian Cracknell <brcracknell@...>
Sent: Thu, 29 Jul 2021 23:09
Subject: [synchronomeelectricclock] Sticking reset

Hello, I am having issues with my clock again. It runs fine for a while and then starts sticking as shown in this Youtube video (link below). The armature does not get grabbed by the coils properly when it should be impulsed leading to the ugly delay evident in the video which has adverse effects on timekeeping.

The current in the system is set to 330mA. Everything is clean; I have tried two separate power sources with the same result. I am currently using a mains plug-in transformer/rectifier running at 4.5 volts output with appropriate resistors. 

Previously I have fixed this issue by adjusting the backstop screw for the armature to being it closer to the coils and also adjusting the contact screw to move that the other way to keep the gap constant. That worked for a while but now the fault has reoccured. I always make sure that the screws are tightly locked in place after each adjustment so I do not think they are wobbling and reverting to a bad state.

Frustratingly, the "stickiness" may well disappear for a while the following day without any intervention and the gravity arm reverts to a healthy briskness in its reset. The improvement is generally short lived.

I would welcome any opinions.


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