Pendulum enquiry

[Michael GilliganParticipant @michaelgilligan61133]

Posted by roy entwistle on 24/07/2019 20:47:04:

Apologies all round I was confusing Wilding's egg timer with his alarm clock, sorry blame it on a senior moment

Roy

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Easily done, Roy … both breakfast related

I understand that JW may currently be working on coffee-grinder and tea-maker attachments

< honest >

MichaelG.

[Tim StevensParticipant @timstevens64731]

Can I start from first principles?

All that is needed is a device which gives the pendulum a prod as it passes. This need not happen every time, or even regularly, as long as the movement is so free of friction that it swings for several cycles without further impulse. It is easier, though, to prod every time. The actual prod can be mechanical, or electro-magnetic (etc).

It might be worth trying a pendulum supported, pivoted, at the top of an upright strut, which itself swing a small amount round a pivot at its lower end. The strut is what receives the nudge or prod, so the pivot for the pendulum moves slightly too and fro, and this keeps the swing in action.

As the strut moves to and fro it can operate microswitches, which would be more stable in operation on a two-position flip-flop strut than on the continually moving pendulum itself.

Unless, of course, you actually need an escapement wheel – which is a lot of work for no real benefit for driving a pendulum on its own.

Unless I have mis-understood (again).

Cheers, Tim

Edited By Tim Stevens on 24/07/2019 22:42:41

[Mark P.Participant @markp]

Don't suppose that it could be based on a metronome?

Mark P.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Tim Stevens on 24/07/2019 22:41:05:

Can I start from first principles?

All that is needed is a device which gives the pendulum a prod as it passes. [ … ]

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An admirable sentiment, Tim … But I think those first principles need to include compliance with the customer's outline specification.

What I have gleaned so far is that he desires to build an 'art installation' comprising a swinging pendulum, (approximately two metres long), that is visually interesting, weight driven, and fully mechanical.

An important 'not yet known' might be … "wall-mounted or free-standing ?"

If 'all that is needed' was a way to maintain a pendulum in motion, then [for example] the Hipp toggle is a wonderful solution; but I think it falls at the first hurdle for plasma's 'beating heart of the house'

MichaelG.

[Author]

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