# Designing a Gearing System for an Analog Clock: Need Help!

In summary, the speaker is struggling to design the gearing for their analog clock and is seeking guidance on the best way to gear the stepper motor and servo. They suggest using a 1/4 turn drive for the stepper motor and a frequency of 1 turn per minute for the servo to reduce wear, but are open to other suggestions. They also mention needing 4 gears and 4 pinions for the gearing and suggest a reduction ratio of 60 for the minute hand and 12 for the hour hand. They ask for a simplified explanation on how to properly gear the clock.
This task seems to me like it should be rather menial but I can't seem to wrap my head around it. I've already designed a circuit to run an analog clock with components I have already got sitting around my work bench. When it comes to designing the gearing though, I am struggling.

My basic idea is this...
1/4 of a turn of my stepper motor will be equal to one second

My servo is a 1/64 turn servo so the simple way of doing this is out the window. The math for the programming is simple. The math for the gearing eludes me. I'm not sure really what makes sense. I think I need to have 4 gears to reduce the gear size. So, 4 gears and 4 pinions. I expect that my servo will drive my minutes hand, and my hours hand will be geared off of that.

So, 1 turn for 4 seconds.
15 turns for 1 minute
900 turns for 1 hour
10,800 turns for 12 hours

Would someone explain to my mechanically simpleton mind a simplified version of how to properly gear this?

Edit: It doesn't need to remain a 1/4 turn drive. It would probably be easier for each step to somehow represent a bit of time, or I could pass a single step every .9375 seconds (60/.9375=64 "Steps"). It would be less wear on the motor as well if I use it less often, or more often with smaller steps.

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This task seems to me like it should be rather menial but I can't seem to wrap my head around it. I've already designed a circuit to run an analog clock with components I have already got sitting around my work bench. When it comes to designing the gearing though, I am struggling.

My basic idea is this...
1/4 of a turn of my stepper motor will be equal to one second

My servo is a 1/64 turn servo so the simple way of doing this is out the window. The math for the programming is simple. The math for the gearing eludes me. I'm not sure really what makes sense. I think I need to have 4 gears to reduce the gear size. So, 4 gears and 4 pinions. I expect that my servo will drive my minutes hand, and my hours hand will be geared off of that.

So, 1 turn for 4 seconds.
15 turns for 1 minute
900 turns for 1 hour
10,800 turns for 12 hours

Would someone explain to my mechanically simpleton mind a simplified version of how to properly gear this?

Edit: It doesn't need to remain a 1/4 turn drive. It would probably be easier for each step to somehow represent a bit of time, or I could pass a single step every .9375 seconds (60/.9375=64 "Steps"). It would be less wear on the motor as well if I use it less often, or more often with smaller steps.
If you choose the frequency (as you suggest) so the motor turns once a minute, you would need a reduction by 60 to drive a minute hand followed by a reduction of 12 to drive the hour hand. These ratios must surely be standard in clock making.

## 1. How do you determine the gear ratio for an analog clock?

The gear ratio for an analog clock is determined by the number of teeth on the gears. The gear ratio for the hour hand is usually 1:12, meaning that the minute hand rotates 12 times for every 1 rotation of the hour hand. The gear ratio for the minute hand is 1:60, meaning that the second hand rotates 60 times for every 1 rotation of the minute hand.

## 2. What materials are commonly used for gears in an analog clock?

The most commonly used materials for gears in an analog clock are brass, steel, and plastic. Brass and steel are durable and can withstand the constant movement of the gears, while plastic is a more affordable option.

## 3. How do you calculate the size of the gears for an analog clock?

The size of the gears for an analog clock is determined by the size of the clock face and the desired gear ratio. The diameter of the gears should be proportional to the size of the clock face and the gear ratio should be adjusted accordingly to ensure accurate timekeeping.

## 4. How do you ensure the gears in an analog clock are properly aligned?

To ensure proper alignment of the gears in an analog clock, precise measurements and careful construction are necessary. The center axes of the gears should be perfectly aligned and the teeth should be evenly spaced to prevent any slipping or jamming.

## 5. Can a gearing system for an analog clock be customized for different timekeeping systems?

Yes, the gearing system for an analog clock can be customized for different timekeeping systems such as 12-hour or 24-hour time. This can be achieved by adjusting the gear ratios and the number of teeth on the gears for each hand to match the desired timekeeping system.

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