# Controling an analog clock



## zac850 (Mar 1, 2005)

My schools upcoming musical requires the an analog clock to be on the set. The play is 1940's Radio Hour. It is an hour and a half on the set of a Radio studio, and there is a clock in the radio studio. While it is not 100% imperative that the clock be controllable, it would be very nice as people take time cues off it ("The time is 9:00 *chme*" is in the script). 

Does anyone know a good way to control an analog clock? I am trying to figure out a way to open the back of the clock up and make a crew member able to change the time, but is there a good way of doing this?

Anyone done anything like that?


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## Peter (Mar 1, 2005)

I guess it depends on what kinda clock you are using and what is behind it. Many clocks just have a hole thorugh the middle with the axel of the clock motor running through it attached to the hands. The slightly tricky part of this is the fact that the clocks i have worked with do not have a solid axel, it is instead layered so that each hand spins at the correct speed. 

I know you can get clock motors like the ones I am talking about (with the hands to go on it, so basicly you just supply the casing and numbers) at almost any craft store. (my dad uses them when he does a progject with making wood burned clocks at some reatreats we go to) You might want to pick up one of these and mabye mess with the voltage being supplied to it. They usually run off an AA batt. or something like that, you could try gently changing the voltage/amperage and see if that makes the clock go faster or slower. If you pick up the clock motors cheap enough, it wont really matter if you burn one up trying (just dont hurt yourself doing it!).


As a low tech alternative, you could always try something like sliding two straws (or one straw and a stirrer) inside eachother and attaching each to one of the hands, and then have someone spin the straws from the other side of the "wall" (ya, i would probably be good to use something besides straws.... but they are what come to mind)

I hope these ideas get you started!


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## Mayhem (Mar 1, 2005)

Other than having a set time (as for the cue example you gave) what would your requirements be?

I am just wondering if a variable voltage supply could be wired up to the mechanism in the clock that could allow you some control over the speed at which the hands move.

Normally such mechanisms run off 1.5 or 3V DC. In theory, doubling the voltage should make the clock run at 2x and so on. It is (in theory) then possible to vary the speed for different settings and during non-time related sections of the play, the clock could be running at what ever rate you require. May be useful to spread the 90 minutes over the time that your productions runs, including intermission.

It would take some playing about with but if you have the time it may work out. As I said – a lot would depend upon your requirements and if this theory actually works.


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## ccfan213 (Mar 1, 2005)

is there more than one reference to the clock in each scene? otherwiser you could have someone just take it down and change it


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## zac850 (Mar 6, 2005)

The clock is supposed to be just that, a normal clock. It is supposed to sit on the wall. In the perfect world, it would take exactly the right amount of time to get to a certain point in the show, when they say what time it is.

I will look into changing the voltage of the clock, which could help if we are running to fast or to slow.


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## Mayhem (Mar 8, 2005)

Yes - but utopia aside, is you production going to be in a perfect world, in real time?


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## avkid (Mar 8, 2005)

Zac, ask your school maintenance guys for an old clock and a control unit,all standard carbon copy type mass installation clocks have a central control unit of some kind.


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## cutlunch (Mar 8, 2005)

Two suggestions:

One) Build the clock out of mecano with the shafts sticking out the back for stage crew to operate.

Two) replace the motor with a small stepper motor and controller, you can change the speed of the clock easily.

Unless the clock is giant size the audience won't notice it most of the time until it is refered to, so stage crew opereating it from the back probably wouldn't be noticed.

If you are using sound effects for the clock chime etc then when the time gets changed won't matter so much. E.g for the Nine O'Clock chime the hands could be moved while there is enough action on stage so the audience won't notice. They'll only think about the clock when it chimes or is mentioned in the script.


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