Why do flip clock motors stop working? And how do we fix them .... are our motors doomed?
I'm starting to believe that, basically, our flip clocks are doomed unless someone starts manufacturing replacement motors.
As anyone who's been around vintage flip clocks knows, one of the primary problems is that after 40 years or so, these motors just stop working. For a few years now, I was sure that the problem was dust and oils in the air getting between the spinning portion of the motor (rotor) and the stationary part (stator) - that's the part that looks like a squirrel cage, beneath which is copper windings. These motors were returned to service after spinning the motor in alcohol. This removed the oils and dust, I thought. In any event, the motors worked again. I believe now that for many cases I was wrong.
When you get right down to it, the only thing that moves on these motors is the rotor the spins the axle. On the end of the axle (inside the gear box), you'll typically find a brass gear, that for most motors, turns nylon (plastic) gears that eventually power the clock mechanism. For years I figured the axle was located inside of a brass bushing or tube.
Today, I tore apart a motor that had play in the rotor. It was an extra motor and I had no intention of using it. That play is what I think causes the motor to make a sound when running. I figured that perhaps the axle would show signs of wear. But there was none. However, as I pulled the axle out and pushed in back in I could feel a bump. This was only when as I pulled it out I sort of tilted the axle - that is, I didn't pull it straight out, I tried to run the end of the axle up against the tube. After a while I could sense that inside the center of the brass tube was a valley or indention. On a hunch, I put a wad of grease inside the tube to try to fill in that valley. Immediately I could tell that the rotor was more stable and had much less play (it spun, but not perfectly).
I believe that these motors must have been manufactured with a permanent, self lubricating bushing of some sort of grease-type substance. Over the years this kept the axle lubricated but eventually the grease or bushing degraded, causing the axle to bind up. Using WD-40 or alcohol apparently liquefies the grease sufficiently allowing the axle to rotate again.
I have no idea how long this will keep the motors going.
Another person who restores clocks told me that he oils his motors yearly. He seemed to imply that he was preventing breakdown of the motor. But why would you need to yearly oil a motor that previously had worked without fail for 10, 20 and more years. Unless I'm right about the tube holding the axle having a grease-type bushing. Perhaps this practice of taking the clock apart and oiling the motor is a good idea. I'd say so, if you already had to free up the motor in the past. But if the clock has been working - I'd leave it alone.
The thing is, we have to accept this ... these motors were not intended to last forever and are not designed to be serviced.... by anyone (even "authorized service personnel").
The motor I disassembled would be very hard to get back into service. It could be done, but the results would be questionable. In most cases tearing down these motors to get some sort of grease in the axle would not be worth the likely damage to the whole system.
Is Alcohol a mistake? Maybe so. Alcohol breaks down grease. Maybe the way I've been doing it liquefies the grease inside the tube enough to let it work again. But I'm thinking that we may need to go to another solvent/oil. WD-40 itself will act like a solvent, breaking down the grease. You know you can use WD-40 to clear parts and remove adhesives. Some have suggested synthetic oil. I've tried that on really frozen motors and it doesn't seem to work by itself. It works fine after the alcohol treatment though.
Why don't we know any of this for sure? We have to keep in mind ... these clocks were designed and manufactured when very few if any companies kept records on computers. And for sure, none of this information made it to the internet.
I'm going to cut into that clock motor eventually and see if I'm right about that valley. But looking inside that small hole with a light .. I'm pretty sure I can see it.
So what's the next step. Well, we have to get those motors spinning. whatever is on that axle has to be lubricated. We just have to find a better solvent/oil solution.
I'm starting to believe that, basically, our flip clocks are doomed unless someone starts manufacturing replacement motors.
As anyone who's been around vintage flip clocks knows, one of the primary problems is that after 40 years or so, these motors just stop working. For a few years now, I was sure that the problem was dust and oils in the air getting between the spinning portion of the motor (rotor) and the stationary part (stator) - that's the part that looks like a squirrel cage, beneath which is copper windings. These motors were returned to service after spinning the motor in alcohol. This removed the oils and dust, I thought. In any event, the motors worked again. I believe now that for many cases I was wrong.
When you get right down to it, the only thing that moves on these motors is the rotor the spins the axle. On the end of the axle (inside the gear box), you'll typically find a brass gear, that for most motors, turns nylon (plastic) gears that eventually power the clock mechanism. For years I figured the axle was located inside of a brass bushing or tube.
Today, I tore apart a motor that had play in the rotor. It was an extra motor and I had no intention of using it. That play is what I think causes the motor to make a sound when running. I figured that perhaps the axle would show signs of wear. But there was none. However, as I pulled the axle out and pushed in back in I could feel a bump. This was only when as I pulled it out I sort of tilted the axle - that is, I didn't pull it straight out, I tried to run the end of the axle up against the tube. After a while I could sense that inside the center of the brass tube was a valley or indention. On a hunch, I put a wad of grease inside the tube to try to fill in that valley. Immediately I could tell that the rotor was more stable and had much less play (it spun, but not perfectly).
I believe that these motors must have been manufactured with a permanent, self lubricating bushing of some sort of grease-type substance. Over the years this kept the axle lubricated but eventually the grease or bushing degraded, causing the axle to bind up. Using WD-40 or alcohol apparently liquefies the grease sufficiently allowing the axle to rotate again.
I have no idea how long this will keep the motors going.
Another person who restores clocks told me that he oils his motors yearly. He seemed to imply that he was preventing breakdown of the motor. But why would you need to yearly oil a motor that previously had worked without fail for 10, 20 and more years. Unless I'm right about the tube holding the axle having a grease-type bushing. Perhaps this practice of taking the clock apart and oiling the motor is a good idea. I'd say so, if you already had to free up the motor in the past. But if the clock has been working - I'd leave it alone.
The thing is, we have to accept this ... these motors were not intended to last forever and are not designed to be serviced.... by anyone (even "authorized service personnel").
The motor I disassembled would be very hard to get back into service. It could be done, but the results would be questionable. In most cases tearing down these motors to get some sort of grease in the axle would not be worth the likely damage to the whole system.
Is Alcohol a mistake? Maybe so. Alcohol breaks down grease. Maybe the way I've been doing it liquefies the grease inside the tube enough to let it work again. But I'm thinking that we may need to go to another solvent/oil. WD-40 itself will act like a solvent, breaking down the grease. You know you can use WD-40 to clear parts and remove adhesives. Some have suggested synthetic oil. I've tried that on really frozen motors and it doesn't seem to work by itself. It works fine after the alcohol treatment though.
Why don't we know any of this for sure? We have to keep in mind ... these clocks were designed and manufactured when very few if any companies kept records on computers. And for sure, none of this information made it to the internet.
I'm going to cut into that clock motor eventually and see if I'm right about that valley. But looking inside that small hole with a light .. I'm pretty sure I can see it.
So what's the next step. Well, we have to get those motors spinning. whatever is on that axle has to be lubricated. We just have to find a better solvent/oil solution.
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