In restoring my Sankyos, I of course needed new motor gears. These gears are made from rubber (for a good reason) and deteriorate over time. I figured that a tougher gear wouldn't deteriorate like the original ones and therefore wouldn't need to be replaced. This is incorrect. The gears are rubber due to the nature of the Intermatic motors used in them. Using a solid gear will cause the motor to yank teeth from the grey gear it engages. The motor gear is rubber to prevent this damage. If you damage that second, grey gear, it's game over as it has a larger center bore than the ones on other Intermatic motors. I now have two Sankyos that are dead in the water due to my ignorance on this topic. Don't make my mistake. 
-
-
Sorry to hear that, but that's odd, you mean the originals are from flexible rubber? I've never seen these gears from rubber, only from plastic, solid plastic, non-flexible... -
I'm referring to the gear directly on the motor. The teeth portion of that is rubber. Not the grey ones.Originally posted by flipoclock View PostComment
-
Sorry, my bad. I see what you mean. I have replaced these with plastic ones and (most?) of these clocks are still running fine so not sure what is going on there. I do agree that they probably used rubber for a reason...Comment
-
I have repaired a few of these motors where the small gear was broken. The material was very soft and disintegrating and I always thought that that was some kind plastic that deteriorates with age, but maybe it indeed was a kind of rubber. I have replaced the broken gears with plastic gears (POM), see this post: https://www.flipclockfans.com/forum/...nning-too-fast
Some have been running for almost two years now without problems.
What material did you replace the gear with?Comment
-
Now that I'm thinking about this a bit longer, I think it is a culmination of factors. The small gear and the large gear in your clock were both old and at the point of self-destruction. The small one had gone but the large one not yet. The large one was now being attacked by a hard plastic gearwheel as opposed to a softer wheel and since the large one was already at the point of destruction, this was what helped it to the 'other side'...Comment
-
Comment