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Want to make cheap quartz clock turn paper gear. Need more torque...how? Answered

I followed one Instructable to create 4 different size paper gears and I've got a cheap quartz clock that I've stripped down to just the guts. Inside the clock was a small circuit board with quartz crystal and smaller plastic gears that move the hands of the clock. I'd LOVE to make the part of the clock that moves the second hand move the small paper gear that will then move the other 3 bigger gears. I've done a test fit but the parts of the clock don't have enough torque to cause the smaller gear to move the bigger one... ideas?

I was thinking I could wire the quartz mechanism to act as a switch to power a small motor on/of each second. Will that work? I know that the voltage necessary to power the quartz crystal is really small, so I might be able to get away with powering the small motor AND quartz mechanism with the same AA battery, I could do separate power sources though...

Here's the link to the gears instructable



Best Answer 9 years ago

i tried a very similar thing once-powering a series of gears using the second hand on a clock. the motor is just too weak and when you think about it, all the motor has to do is move one little tiny second hand that probably weighs like a gram. i would recommend building an amplifier circuit and getting a more powerful motor. if you are absolutely bent on using the motor that's already there then you need to have a lot of gears count how many teeth are on the gear attached to the motor. then pick a ratio like 10,000:1 get several larger gears and attach them to the smaller gears so when the motor spins it barely moves the largest gear. now you've got a lot of torque. i bet you could move a car with that motor if you geared it the right way and had several eons to wait. and by the way when i did this we ended up scraping the idea of using a clock and just used a plain store-bought motor.

I figured it was too weak. I don't know much about microcontroller programming so that's why I want to use the quartz crystal as a "switch" in a sense for a more robust motor... is this still possible? battery to quartz. each "tick" is on/off on a switch between said battery and larger motor. can't I just ground them to the same battery and have the switch "close" whenever there's a surge in the quartz? btw, I don't know much about voltage either. Thanks for your help and the help of any others!

well i don't know what type of quartz timer your using but i'd bet that it's only able to handle a limited amount of current. this means that if you want to use the quartz timer it's only going to be able to process so much current (it's maximum is probably a weak motor like the one already attached). to answer your first question i would say that yes it is possible but it may be more trouble than it's worth. as previously mentioned you would need an amplifier and probably an external power source to amplify your signal. then you need to find a motor that matches the signal. i'm not quite sure what you mean when you say "close"? are you saying that when the switch is "closes" it completes the circuit? or do you mean "close" as in it disconnects the circuit. if you mean that it disconnects the circuit i would say that what you have sounds like a good idea-maybe. first off if you want a more robust motor it's going to draw more current. if it draws more current you need to feed it more current (aka a more powerful battery). now if you've got a more powerful battery attached to this circuit that was built to run off for example AA's and then you attach for example a 9.6V or 7.2V battery to it. it's probably going to fry the circuit before it ever makes it to the motor. now i said earlier i don't know what type of quartz timer and circuit you have but i'd guess that the increased current would be too much for the circuit. that is why i suggested using an amplifier circuit if you are bent on using the clock components. you would power the circuit with the same weak, for example AA's, and it would then send an output signal to what used to be the motor but is now the amplifier circuit which is powered by a battery or from a transformer on the wall. the amplifier circuit keeps everything the same except it adds more energy to the signal so that it is able to power the motor.

what I meant is when it ticks it'll close the circuit to complete it. I see what you mean about having to amplify the signal. I think I need to do more research on the quartz timer in the cheap clock that I have before I really get going on this project. I'll keep you posted. Thanks for all your help!