- #1
lesaid
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I'm about to pick up again on a project started last summer to build a Foucault pendulum that will fit on, or at least, above a desk in an ordinary room. This was described, with photographs in https://www.physicsforums.com/threa...or-physics-project.890835/page-3#post-5845824
The pendulum (about 1.2 m in length with a 1.5 kg bob) pivots on a 1mm ruby sphere at the tip of a 'probe', that rests on a hard platform. The hardest surface I have found so far is a piece of glazed dinner plate - but it seems this is not hard enough. After some time running, the platform is pockmarked with tiny pits, which I suspect will be influencing the swing.
Does anyone have any ideas for a material that is
I had the pendulum working well last summer, running for nearly six hours before the (unpowered) swing decayed too much to establish its direction, and showing rotation at the expected rate for my latitude. I then disassembled it to make some modifications but on reassembly, it no longer worked (swing settled into a preferred direction over three or four hours). I think the problem lies in the structure that supports the pivot, so my first task will be to design a more robust (very rigid but finely adjustable) version.
Other thoughts or ideas welcome!
The pendulum (about 1.2 m in length with a 1.5 kg bob) pivots on a 1mm ruby sphere at the tip of a 'probe', that rests on a hard platform. The hardest surface I have found so far is a piece of glazed dinner plate - but it seems this is not hard enough. After some time running, the platform is pockmarked with tiny pits, which I suspect will be influencing the swing.
Does anyone have any ideas for a material that is
- very hard (harder/stronger then glazed china)
- very smooth
- readily available without being too expensive
- can be cut or broken into a piece that provides a roughly square/circular platform around 3 cm across with a very flat top surface and not more than about 1 cm thick
- Will support a weight in excess of 1.5 kg on the 1 mm ruby sphere
I had the pendulum working well last summer, running for nearly six hours before the (unpowered) swing decayed too much to establish its direction, and showing rotation at the expected rate for my latitude. I then disassembled it to make some modifications but on reassembly, it no longer worked (swing settled into a preferred direction over three or four hours). I think the problem lies in the structure that supports the pivot, so my first task will be to design a more robust (very rigid but finely adjustable) version.
Other thoughts or ideas welcome!
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