Hi all - my first post here and a weird one.
For a film based in the sixties, they need as a suspense building prop, a large flip clock that is at least 6 digits long (HH:MM:SS) and that is also required to count DOWN to doomsday in seconds. Now before you all point out that counting in seconds will be noisy and it'll wear out the mech in no time, please just remind yourself that this is film and everything in films is just pretend and very temporary! OK? This will only have to work for an hour or two whilst being filmed. Nothing on the market I'm sure that does this? Obviously you can't just turn the motor backwards as the flaps move down by gravity and where I live at least, gravity works strictly top to bottom. A stylish Cloudnola clock has been bought to experiment on with the possibility of adding another (unlinked) to the left to give days and hours.
I initially thought that I could simply remove all 60 of the minutes flaps from the drum & reassemble them in reverse order. However this won't work as they're all printed double sided and the tops and bottoms of characters won't match if they've been put out of their original order. So I'm thinking that one side of each flap at least would have to be reprinted - vinyl lettering or something which is very tedious but I suppose doable. Being battery powered, I also initially thought that this clock would contain some kind of simple impulse motor driven by a pulse every 60 seconds. Wrong again as the purpose made motor is synchronous, spinning continuously from an 8 Hz sine wave produced from a battery powered tiny electronics module stabilised with a quartz crystal. To make the clock count in seconds, everything needs to be running 60 times faster than the original design. Being electronics minded, I tried feeding in a variable frequency sine wave from a signal generator directly into the motor coil but found that the motor only works over a fairly narrow frequency range of about 5 - 40 Hz. I need it to run on 480 Hz so it's still spinning way too slow. The motor is followed by a cascade of six tiny nylon gears to bring the final minutes spindle speed down to 1 Rev Per Hour. I hoped I might be able to reverse the order of some of some gears but they're all different sizes so this isn't possible either. I think the gear train would have to be re-engineered which I'm not too keen on as I've never yet managed to so much as drill a hole in exactly the right place & these things are very tiny so machining accuracy would be critical.
For the curious I'm including some pictures of the clock, its components and closeups of the motor mech. The motor assembly fits into a circular well in the central support column which also contains the D size battery.
So I'm wondering if anyone has ever heard of such an extreme level of electro-mechanical customisation that is required for such a project or is there any clock available that is driven by a simple solenoid mechanism that can be jabbed at one sec intervals with a simple switch rather than a continuously running motor? Thanks if you can help.
For a film based in the sixties, they need as a suspense building prop, a large flip clock that is at least 6 digits long (HH:MM:SS) and that is also required to count DOWN to doomsday in seconds. Now before you all point out that counting in seconds will be noisy and it'll wear out the mech in no time, please just remind yourself that this is film and everything in films is just pretend and very temporary! OK? This will only have to work for an hour or two whilst being filmed. Nothing on the market I'm sure that does this? Obviously you can't just turn the motor backwards as the flaps move down by gravity and where I live at least, gravity works strictly top to bottom. A stylish Cloudnola clock has been bought to experiment on with the possibility of adding another (unlinked) to the left to give days and hours.
I initially thought that I could simply remove all 60 of the minutes flaps from the drum & reassemble them in reverse order. However this won't work as they're all printed double sided and the tops and bottoms of characters won't match if they've been put out of their original order. So I'm thinking that one side of each flap at least would have to be reprinted - vinyl lettering or something which is very tedious but I suppose doable. Being battery powered, I also initially thought that this clock would contain some kind of simple impulse motor driven by a pulse every 60 seconds. Wrong again as the purpose made motor is synchronous, spinning continuously from an 8 Hz sine wave produced from a battery powered tiny electronics module stabilised with a quartz crystal. To make the clock count in seconds, everything needs to be running 60 times faster than the original design. Being electronics minded, I tried feeding in a variable frequency sine wave from a signal generator directly into the motor coil but found that the motor only works over a fairly narrow frequency range of about 5 - 40 Hz. I need it to run on 480 Hz so it's still spinning way too slow. The motor is followed by a cascade of six tiny nylon gears to bring the final minutes spindle speed down to 1 Rev Per Hour. I hoped I might be able to reverse the order of some of some gears but they're all different sizes so this isn't possible either. I think the gear train would have to be re-engineered which I'm not too keen on as I've never yet managed to so much as drill a hole in exactly the right place & these things are very tiny so machining accuracy would be critical.
For the curious I'm including some pictures of the clock, its components and closeups of the motor mech. The motor assembly fits into a circular well in the central support column which also contains the D size battery.
So I'm wondering if anyone has ever heard of such an extreme level of electro-mechanical customisation that is required for such a project or is there any clock available that is driven by a simple solenoid mechanism that can be jabbed at one sec intervals with a simple switch rather than a continuously running motor? Thanks if you can help.
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