Clock question #4

[Mark BusParticipant @markbus97330]

[Mark BusParticipant @markbus97330]

Hi,

I'm thinking about building the W. R. Smith skeleton wall clock ; it's supposed to be simple to build which is what I want. Of course, however , I have to complicate things. I would really like it to be larger so it would look more impressive . Can clocks be scaled up and how does one do that ? I was thinking that keeping the ratios between the gear sets the same would be the thing to do ?

Thanks,

Mark

[John HaineParticipant @johnhaine32865]

You could scale it up, but not the pendulum length because its period varies as the square root of length. So you need to keep the pendulum length the same, about a metre for a seconds pendulum. So the proportions of the clock will change. There are ways of counteracting this, you could arrange for the pendulum centre of gravity to be well above what appears to be its bob, but it won't do much for accuracy if that's a concern. If you scale everything you would need to change the gear ratios.

[Mark BusParticipant @markbus97330]

Hi,

What I want is a clock with a less ornate frame and larger gears. The clock uses a .8 Mod cutter for the going train. My most recent idea is to use the 1Mod cutter from the Wilding Brass Alarm Clock,so I don't have to buy another cutter, keep all the gear ratios and tooth counts the same and cut the gears with that . The PCD's would change and so would the OD's . The lantern pinions would be larger too.

All other things being equal, if that's possible, is a clock with larger Module gears as accurate as a clock with smaller M gears ? Does Module size affect accuracy ?

Thanks,

Mark

[Stephen BensonParticipant @stephenbenson75261]

Well Wilding's Small Weight driven Tower Clock uses Mod 1 throughout, has large gears; is certainly impressive and not difficult to build.

Smaller modules effect size which in turn reduces the power requirements which then allows for more wheels for longer running but does not improve the accuracy by a huge amount.

Edited By Stephen Benson on 02/02/2015 08:55:54

[roy entwistleParticipant @royentwistle24699]

Re John Haine You do not alter the gear ratios What you could do is up the tooth count ie use 12 leaf pinions

( orn trundles if lantern ) and increase the wheel count by the same factor

Roy

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